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A Mexican tale about life

2012-01-21T10:03:00.000+01:00

One day a rich Westerner who had made sqillions from speculating on the stock market was strolling along the beach and saw the fisherman pulling in his boat with his meager catch.

The rich Westerner stopped and remarked “not much of a catch today”. The fisherman replied “yes not much” but explained that his small catch was enough for him and his family.

The rich Westerner asked, “But what do you do with the rest of your time?”

“I sleep late, play with my children and have an afternoon’s rest under a coconut tree. In the evenings, I go to the local pub to see my friends, play some music, and sing a few songs….. I have a full and happy life.” replied the fisherman.

The rich Westerner ventured, “I have an MBA from Harvard and I can help you…… You should start by fishing longer every day. You can then sell the extra fish you catch. With the extra revenue, you can buy a bigger boat. With the extra money the larger boat will bring, you can buy a second one and a third one and so on until you have a large fleet. Instead of selling your fish to a middleman, you can negotiate directly with the processing plants and maybe even open your own plant. You can then leave this little village and move to a city from where you can direct your huge enterprise.”

“And after that?” asked the fisherman.

“After that? That’s when it gets really interesting,” answered the rich Westerner, laughing, “When your business gets really big, you can start selling stock in your company and make millions!”

“Millions? Really? And after that?” pressed the fisherman.

“After that you’ll be able to retire, move out to a small village by the sea, sleep in late every day, spend time with your family, go fishing, take afternoon naps under a coconut tree, and spend relaxing evenings with friends…”

Author?

Dongria Kondh’s resistance against Vedanta

2012-01-19T09:59:00.000+01:00

Extracts:

"They [Vedanta, a mining company] want to take these rocks [bauxite, the raw material of aluminium] from the mountain. These rocks are the reason our children can live here. Because of these, the rain comes. The winter comes, the wind blows, the mountain brings all the water. If they take away these rocks, we'll all die. We'll lose our soul."

"Initially, they [Dongria Kondh, the locals] welcomed the company. But now they realize their mistake, because they live like dogs. Now they realize they've lost their land and their homes forever.

"When people said they wouldn't leave, they [Vedenta] came with bulldozers at night and demolished their home."

"But now the bauxite dust is mixing into the wells and streams."

"Now they're trying to tell us that the company will do good things. But we say, "You don't have to take care of us. We can take care of ourselves. We'll lead our lives the way we know."

The Crisis in Education

2012-01-17T15:58:00.000+01:00

We are in a multi-crisis world according to experts. Our civilization is in crisis. Civilization is failing because education is also in crisis -a chain of crisis, so to speak-. Values are no longer respected and kids are disoriented. Knowledge is being taken over by specialized skills, and many things that were known and considered the pillars of humanity are being forgotten. Wisdom is obsolete, nobody seeks nowadays to develop his/her soul and to find peace of mind. Habits are battled away by the constant changes and enormous leaps in civilization, i.e., those who learned a set of essential habits to live and appreciate the world as it was don't understand anymore and can't live in the new state of the world; and those who learned the new set of essential habits can't communicate with those who were living in the old world, and can't understand its richness.

Many explanations account for the decrepitude of education. One of them, the institutionalist approach, states that education is failing because institutions that have the burden of educating children, don't have the appropriate means to fulfill their mission. To solve this problem, pro-instutionnalists think, accordingly to this paradigm, that, in order to help the institutions to fulfill their mission, means must be given to restore their efficiency. Pro-institutionnalists range from conservatives (more books and discipline) to progressivists (new methods and more freedom).

I intend to show here that this solution is missing the point and argue i) that the current organization of education disrupt the mechanisms of education, and ii) that current teaching is too far from the real application of children's (and our's by extension) capacities. Let me say first that I'm not the advocate of "More morals and work at home" school. I think it's besides the point. It's not that parents are doing something wrong, it's that parents can't do anything, because almost everything in the organization of our western society is preventing them to do anything.

Let's begin with the basics. What is education? And what is its purpose? It's the means through which a group of people passes on its habits, its wisdom, its knowledge, its set of values, to the next generation. What are the means? Mainly the means are parenthood, family and group, sports, and formal education (schools, universities… any organized institution that aims to teach some skills and knowledge, whether it's State or privately funded).

1) Parents with no teaching power.

Who is nowadays carrying out the mission of education? Schooling institutions and sport clubs mostly. And for a few hours per week in the best case, parents. Who's in charge of passing on knowledge? School. Who's in charge now of teaching values? School and sometimes parents. Who's in charge of passing on habits? School, sports and nursery. Who's in charge of nurturing the soul of the kid? I don't know. The Church (whatever it is) if the baby or the child is in a family with religious beliefs.

When we think, when children think nowadays, about physical activities, when we think about teaching physical habits and skills, we think about sports. When we want to see our kids physically active, we enroll them in a dance, kung fu, athletics, wrestling, running, tennis, soccer… class. To us, sports seems to be everything there is to know about physical activities, and associations and clubs are where sport takes place. Kids practice sometimes at home, but the core of the training is in the club. Yet, what do we learn in sports? Rules. The importance of performance and winning. Work out. There is no denying it, sport is no physical education. Children don't learn how to move efficiently, why solidarity is important for physical activity and its aims, how to avoid and treat injuries, how to breath correctly, how to defend themselves, etc. My point is that sport claims to be the best way to be active today, and yet it's a poor way to physical activity. Moreover, another problem arises from the fact that it claims to be the only way to physical fitness, and the fact that sport is elitist. Sport's purpose is to select the best achieving person in a highly specialized movement pattern (the fosbury flop, catching a ball, etc) and use them to win. Because winning is always the goal in sports, sport clubs need the bests to win (whatever the prize is, from money to fame or the pride of being better than others). This is why children and people of "average levels" according to their standards are excluded rapidly. And since sport is considered to be the only way to health, strength, and fitness, the left-out are quickly out of shape, not knowing what to do as a physical activity. So the problem with sports is not that it's not fulfilling its purpose. It's that it's doing that too well; that most children and adults are transformed as mere passive watchers, with no idea whatsoever about physical education; that parents, thinking that there is nothing else in physical activities than sports, don't get involved in physical education. They don't get their chance. And that is how some human knowledge, values and habits, disappear. Ending some of the most the basic features of human education.

At school, children learn the abc, the basics of calculus, history, geography, anatomy, evolution, religion, elements of biology, drawing, painting, modeling, physics, technology, philosophy, etc. Even morality is taught at school. Lots of topics of human knowledge are covered at school. Out of school, children are doing something for school (an essay, a translation, a show and tell, etc). School seems to be their alpha and omega. But let's do some analogy reasoning. Who's in charge of the education of a cub? His/her mother and the tribe. What do they teach ? They teach the cub how to hunt, how to feed, how to kill, how to find and recognize a prey, how to play, how to dig the teeth in the flesh and tear it, how to find water, etc. Anything that is valuable to live as a lion. Of course, all these capacities are instincts and grounded as capacities in any cub. But who's in charge of helping the development of the instincts? Who's in charge of sharpening the use of the capacities? The tribe and the mother. Now who's in charge of the education of a baby-bonobo? His/her mother and the tribe. What do they teach? They teach the BB how to brachiate, how to behave with others, how to find the fruits and leaves its need, how to hunt the small animals it needs, how to be oriented in a forest habitat, etc. Anything that is valuable to live as a bonobo. BB's capacities are all instinctual, but tribe and family share the task of sharpening the instincts and the use of BB capacities. And who was in charge of the education of a human baby, 70 000, 9 000, 2000, a few hundreds years ago? Family and tribe. They taught the HB what he/she needed and anything that was valuable to live as a human. Now, I know what you are thinking: this only an analogy argument. It's not because something is or was in a certain way, that it must be that way. Certainly not, I agree. And yet I can't help thinking there is a benefit in the process, because inherited and selected features are in the game. E.g., the fact of presenting some face features as a baby and child, and the disposition of parents of considering this features as an input, of interpreting them as "being cute", entailing the output of care and love of parents and of close people. Other traits are also involved but I can't list them all here. There is no denying it, some traits are made for obtaining a response of love and care from parents, facilitating the educative process. Cubs, bonobos possess these traits and disposition to interpret them. Why not humans?

So what's wrong with schooling institutions? First, they're doing the job the child expects the parents and the close group to do. Consequences? Children are expecting to learn many things from their parents. Instead, they are left with people they know nothing about, that have no importance for them, that they will forget, and that they will never see again. Anonymity seems the rule of the educative process now. Second, they're not teaching what's essential to live as humans and the basics of life. The bound uniting humans, parents and children is dissolved, and the link of human knowledge, values, habits and wisdom, has been replaced by expertise knowledge. Indeed, we're not educating children, teaching them to be adults, we're turning them into lawyer, physician, electrician, philosopher, or plumber. Education has been transformed into functionalization: children learn how to get a function in the society they live in. As such, they will learn to familiarize with an input (for example, a problem in civilian life), learn how to process the input (using civil laws), and produce an output (an application of an appropriate law). From this, they will get a reward (money, social capital, etc) and provide great and useful services to everyone. But that's not what education is about. Education is not about our function, it's about who and what we are. And that's exactly what schooling education is doing wrong: it's turning its back on human education, opening its arms to social functionalization, and breaking the link of human education by preventing parents to share their knowledge, habits, values and wisdom to their children. Who would want to ask for more?

Let me get some things straight. First I'm not an advocate of the caveman politics (macho, sexist and stuff) portrayed sometimes, as some may think I am. I'm husband at home, I'm the one doing the domestic chores and taking care of my children and yet I'm not a woman and I don't have any problem with this. We're doing fine, thank you. As I said: the job THE CHILD EXPECTS THE PARENTS and the close GROUP to do (i.e., not "the job the mother is supposed to do"). I'm not for the time being showing a solution to problem, I'm just showing why a set of interpretation-of-a-problem+solution isn't working. Meaning I'm not an advocate of the solution where one member of the family (a lonely mother for example, while the father is far away making crazy money and suffering from an eternal jet lag) raises alone the child. It's too hard for the child and the parent, and not efficient (because the member of the family "in charge" of education is compelled to ask for the help from institutions, there is no other solution nowadays, with its inherent limitations). Second, I have nothing against functionalization in itself and I don't want to go back to the paleolithic (I'm fond of up-to-date technology, and at peace up to some point with the world I live in). From my point of view, the problem with functionalization arises only when the ratio between education and functionalization becomes too much in favor of functionalization. Third, don't give me the cultural argument crap. Yes I know, human cultures have differences between each other, and that differences may affect the material that is passed on and the way it is from one generation to the other. But it's besides the point.

So the answer may be: let the parents and the close group take care of the children. But no, we can't! Why? First, because schools and sports have incapacitated potential parents. Since school and sports claim to give anything there is to do, care about, and know, and have act accordingly since many generations, potential parents have forgotten what is essential for humans (basics skills and knowledge, physical education, development of the soul), having succumbed to functionalization and overspecialization in sport. Second, because of the organization of our society, many couples with children live in cities, where family and close friends and members of the group are… not that close. They are away, maybe in another country. They don't form a unified unity. They are individuals, that sometimes share a moment together. But the children expect the family and the group, not one person, to educate them, to teach what is worth knowing and doing as humans. The social group is in a way dissolved, and parents find they are unable to carry out alone education. Thus parents leave their children at school and sports' clubs, thinking that they're doing the best they can for their children. With the best intentions. That's how human civilization is failing.

I'm not finished yet. There is another point about the kind of knowledge and know-how children are getting from school and sports.

2) Children not getting the informations they expect and need.

Remember the distinction between proper and actual domain of a module in Dan Sperber's theory of mind? This distinction, applied to capacities in general, may be crucial. To any capacity, there is a bounded domain of stimuli that will trigger an automatic and appropriate response. The proper domain consists in the set of stimulus that it is the capacity's biological function to process, and the actual domain is all the information in the environment that may satisfy the capacity's input conditions (See Sperber 1994) and trigger an output, a response.

What sports do? Basically, a sport isolates one capacity and stimulates it with a certain movement pattern. Think about baseball. A catcher, a thrower, and a beater. Think about athletics. A fast runner, a long-distance runner, a thrower of sticks, a thrower of ball, a jumper. Think about soccer. A catcher, a player with a ball at his feet. No need to continue, you get the picture.

So what's wrong? First, they focus on one capacity only and isolate it from the rest. Do you think we're good because we are experts at one thing? Because we are able to do a fosbury flop? Do you think we survived because we're great at one thing? Well let's see. Compare to a cheetah, the fastest human is really slow. Compare to the most average chimp, the best gymnast looks like a clumsy amateur. Compare to migratory birds, the best long-distance runner is really slow and non-endurant. We don't have any absolute extraordinary capacity. But we're okay at many things. That's how we survived (among other things). When hunted by felines, we could brachiate. When hunted by brachiators or species with good climbing capacities, we could run fast. What's the point of doing one thing when our strength is that we are diversified? You want to know the result of sports? Overspecialized people at one physical movement who are basically unfit (yes, most of them are suffering from inflammations, injuries, asthma…). Weird, no? Second, sports, compare to physical activities, with actual/proper domains distinction as a background, is like being fond of chocolate and having a sweet tooth. Seeing a fruit and wanting to eat it is a normal response; indeed, a fruit belongs to the proper domain of recognition of food's capacity. We need our liver to be full of carbs to be able to run fast if we're attacked, so we developed the capacity to recognize edible food with high sugar material, and the trait spread because it was beneficial (I'm not making this up, there are studies backing this up). Wanting to eat chocolate all day is a gross distortion of the recognition of food capacity. Chocolate triggers the response because it's food, but the capacity was never built for it. Consequences: eat chocolate all day, your liver will be intoxicated and you'll be sick. Sports is exactly like this, a trigger to some capacities that were never built for it, that is intoxicating for your body. We were built to jump, not to do the perfect fosbury flop. Wanting to run when the terrain is smooth is a normal response. Wanting to climb into some trees in a forest, or a pole in a city is a normal response. Interactions with the environment is the keyword of physical activity. But repeating over and over the same physical move is an abnormality. Do a fosbury flop again and again and you'll end up with overuse injuries and lack of balance in structure and capacities. We were built to be physically active in general, not to be super-expert in one movement. Furthermore, Sports creeps on our need to play to instill the need of victory. Soon, performance takes over pleasure; finding the weaknesses in others, and winning something is all the sudden all that matters. And it's not what children are expecting from their parents, it's no real physical education, no value system. It's not useful. Not functional. Body awareness is completely out of question. Pain is something that athletes don't know what to do with, they ignore the best system we have about our health by taking "Vitamin I" (i.e. non steroidal ibuprofen). And pleasure is out of the picture. Incredible. Serena Williams, one the best tennis player in the world, doesn't like to play tennis. It's something, isn't it? Sports uses the body without involving the body. But an involved body is exactly what any child needs. (And any adult, for that matter.)

What about school then? Is there also something wrong with school? From my point of view, school is exactly like sports: a trigger to some capacities that were never built for it, which provokes, from overuse, dysfunctions. Memory, reasoning, focus, ability to build artifacts, creativity, ability to count, read, etc. Is school disregarding the effects of what it does? Take visual capacity (I borrow this example to Forencich, in Exuberant Animals). Do you think it's been built to be focused on one small thing all day long (a book, a screen)? No of course. Why do you think we always have to look at the window sometimes? Because that's exactly why it's been built for. Scan the big picture and focus. Scan and focus. Have you see any animals eating recently? Focus on food, scan the environment to see if there is no predators or challengers. Focus on food, scan the environment. So focus on the screen then scan. If not, the ability to scan in the visual capacity will atrophy and stress will build up in the body, because there is no verification of the environment. Another example. What about the ability to make sounds, the voice ability. At school, they learn to talk nicely and quietly. It's really impressive. But leave children alone in a class for 5 minutes, and they will scream, cry of joy or pain, mimic animals or adults or friends, sing, whisper… Chaos in the room. We say that we can't allow this at school or no teaching will be possible, that they should do that at home. But what do we do at home? "Be quiet. Shut up. You're too loud. Don't scream…" We just don't allow them to explore the whole range of the voice ability. And yet voicing and expressing are the most primal and useful things in humanity. It comes along birth, death, celebration of life, and everything that matters in life or survival (it increases rate of success in hunting of certain tribes who mimic with their voices animals' screams to get their attention and get them closer to hunters). I'm already picturing the teacher saying: it's not practically achievable. Well, first, children are not made to make the life of teachers easy (I know I'm one them, I mean a child and a teacher). Second, it's a basic skill. If not sharpened and explored, we just talk, and use this ability without really training it and involving the whole range of its capacity. Another example, with a less eccentric capacity for Westerners. Reasoning. Most tasks at school consist in finding the correct answer to a question: mathematics as they are taught are the paradigm of this attitude, but they are not alone. In literature, you'll have to find the right name of the figure of speech, the right structure of the text, the right way to spell the name, etc. It's called convergent reasoning (expression coined by Joy Paul Guilford). I always find this extraordinary that children are able to find the right answer most of the time. Because teachers never explain the basic rules of reasoning or the basic rules of argumentation. They just apply innate capacities. That's what school is: application of a small range of capacities without training. Even reasoning is far more complex than that. What about divergent thinking? What about the ground of fallacious reasoning? Mapping? Intuition? Metaknowledge? Hypotheses building? Conclusion, schooling institutions treat capacities like sport clubs do. At school, we apply and use capacities, but we don't train them, refined them, we're not considering the capacities for their own sake. Contrary to what conservatives believe, children don't need to spend more time on books. They need to be able to distinguish between capacities, and to apply them with efficiency and smoothly. Children needs their intellectual capacities and instincts to be sharpened, not loaded or used blindly without any guiding.

Schooling institutions and sports claim to teach valuable things to children. They just miss the point. They hypertrophy capacities while leaving other capacities to atrophy, and induce dysfunctions from overuse and ill-guided use. They just use capacities with stimuli that they were not built to take care of, without training them for their own sake. In one word, the main means of education are not fulfilling their purpose, and, more importantly, it was not the purpose of schooling and sports institutions to do educate, because functionalization and specialization is their primarily role. So the current situation is the following: children spend most of their time at school and sport clubs, and parents think that children are getting what they need at school and sport clubs; but children don't get what they need from school and sports clubs, which weren't built to offer what they need anyway ; children expect wisdom, knowledge, habits, and values from parents, and yet parents, because they also spent most of their time, when they were youngster, at school and in sport clubs, don't know how to train properly children's capacities. So who's doing the job? Who's educating the children? Nobody.

That's the hell of a crisis.

Remember, there is more to education that learning how to get a job.

BBC. Human Planet. Jungles.

Links and thoughts about static stretching

2011-12-06T07:00:00.000+01:00

Many runners stretch before and after a workout or a competition. Often they do static stretching, i.e. they strech a muscle by elongating it, in a static posture for 15-30s or more. The idea is that if we stretch a muscle before and after an effort, it will gain power, elasticity, and it will decrease the chances of being injured.

However, you have to admit that the idea lacks of intuitivity: if you extend a rubber band to its maximum capacity and hold it that way for a long time and repeatedly, then when you relax the tension, at some point, you'll notice that it has lost its capacities, that it has become too loose.

Researchers interested in the biomechanics of sport and physical activities tried to show if static stretching had any benefits. What they found out, when results weren't completely negative (I mean not corroborating the hypothesis that static stretching shows an identified benefit), is that things aren't clear. USA Track & Field conducts a study where results about health benefits are... Well, not clear. See the summary published by Gretchen Reynolds in Does stretching before running prevent injuries:

The study, one of the largest of its kind, involved almost 1,400 runners, from age 13 to past 60, who were assigned randomly to two groups. The first group did not stretch before their runs, while otherwise maintaining their normal workout routine: the same mileage, warm-up (minus any stretching) and so on. The second group stretched, having received photographs and specific instructions for a series of simple, traditional poses, like leaning over and touching toes, that focused on the calf, hamstring and quadriceps muscles. The volunteers were told to hold each stretch for 20 seconds, a technique known as static stretching. The entire routine required three to five minutes and was to be completed immediately before a run.
The volunteers followed their assigned regimens for three months. Predictably, since running, as a sport, has a high injury rate, quite a few became injured during the three months. About 16 percent of the group that didn’t stretch were hobbled badly enough to miss training for at least three days (the researchers’ definition of a running injury), while about 16 percent of the group that did stretch were laid up for the same amount of time. The percentages, in other words, were virtually identical. Static stretching had proved to be a wash in terms of protecting against injury. It “neither prevented nor induced injury when compared with not stretching before running,” the study’s authors concluded, raising the obvious corollary, so why in the world do so many of us still stretch?

To continue with the "non-clear" effect, Gretchen Reynolds, in To stretch or not to stretch, gathers some recent studies where it is shown that, if someone maintains the position of a static stretching for less than 30s, she/he will experience no "detrimental effects". Indeed it seems that over that length of time, you are likely to hurt yourself and diminish your capacities. But that leaves open the question of the benefit of static stretching in the less than 30s condition: does it help us to get injury-free? to be more powerful? faster? What's the point of stretching if it doesn't help us in any way?

In Stretching: the truth, Gretchen Reynolds contrasts static stretching and dynamic stretching. It's an interesting read. According to GR and the background studies of this article, the problem with static stretching is that it doesn't fill the required conditions of stretching: i) increasing the range of motion of joints and, ii) warming up body's temperature.

Personally I stretch dynamically before some workouts, but not every time (some samples of dynamic stretching can be found in Stretching: the truth). If you have to run to save your life or save the life of someone, you will not have a hint 15mn before to warm up. You just run when it's needed.

Running as a global experience

2011-12-04T09:30:00.000+01:00

Why do we run ? According to my experience, we run to flee (from an aggressor or from our anxiety), to hunt (a bus when we are late or a deer when we are hungry), to play (with our friends on Saturday morning).

What do we do when we flee, hunt and play ? We don't just lift our legs one after the other. When we run after the bus, we use our eyes to check where it is and where it can stop. When we flee from an aggressor, we use our ears to listen to his pace, to check if he is far or close; and when we flee from anxiety, we enjoy the feeling of the wind on our face or the inner feeling of wellness. When we run with others in trails with uneven ground, we use the sensation of our feet to adjust our posture and pace, we use our ears to check that our friends are still with us and our eyes to see if they are ok and having fun. (Photo: Jason Bourne (Matt Damon), in a chase scene, his eyes fixed on the target, Bourne Ultimatum.)

Running is a global experience. With the feelings on my skin, I know the quality of the air; with the feelings on my feet, I know what is right under my feet where I stand. With my eyes I know what is just in front of me. With my nose, I know what I can't see, what is behind the next bush. With my ears, I know how things move in any direction, especially what is behind me and on my sides. The touch for the present and where I stand; the hearing for the past and what is behind me and on my sides; the view for the short-term future and what is right in front of us; the smell/ taste for the long-term future and what is far ahead.

Being mindful of my sensory system helped me to get rid of pressure of performance, and improved my technique and posture. Indeed I think we have this finely atune and precise global sensory system for one and only one thing: to adapt, to adjust to our environment. It's not our will or desires that shape our behavior, but the interaction between our capacities and the environment. It's not a pair of shoes with flying wings that dictates if I can run fast everywhere, but how my body can react to my environment with its capacities. If you start thinking about how it hurts to run on sharp rocks, and start thinking about the reason behind this kind of pain (I mean ache not suffering), you begin to realize that your sensory system is not just bothering you and preventing you to achieve your PR, but telling you how to adjust to your environment with the capacities you have. The interaction between the environment and our capacities show us how we can adapt to the features of our environment with efficiency and safety. (Consequence: don't mess with things that alter your sensory system and your brain chemistry, or seclude your sensory system from its environment.)

Why not standing still before running instead of rushing into things without anticipation ? Why not paying attention to this mechanism to know ourselves and our environment during a physical effort, instead of disregarding what we can do and where we are ? Why not unplugging the mp3 and paying attention in running to the functionning of our sensory system? Our capacities might be sharpened. Why not smelling the air to see what kind of plants, flower or ground is ahead, seeing what kind of obstacles and challenge are in front, listening to what can come from any sides? It might be useful.

Parutions du recueil "La Philosophie expérimentale"

2011-11-25T15:00:00.000+01:00

Les éditions Vuibert font paraître un volume de recueil d'articles sur la philosophie expérimentale : Dutant, J., Machery, E., Knobe, J., Nahmias, E., Cova, F., Nichols, S., (eds) (2011), La Philosophie expérimentale. Paris : Vuibert.

J'ai traduit l'article de Nahmias, Morris, Nadelhoffer, et Turner : L'incompatibilisme est-il intuitif ?

The mystery of the sunstone

2011-11-18T11:04:00.000+01:00

In sagas recording Viking navigational stories, it's written that they used stones that could point to the sun in any conditions. A study, directed by Guy Ropars (University of Rennes) and published by the Proceedings of the Royal Society, shows that they may have used a mineral called iceland spar, a form of calcite. The passage of sunlight polarises it, which means that light from the sky points towards the sun, in certain conditions.
Source : the Economist, Discovery News.

MAJ (19/11/2011) : someone I know reacted to this post by saying that sometimes we have the feeling that with our technology we can do more things that we ever did, but often it's just that we have forgotten how we did it before. Moreover, even if with technology we are able to do things that were forgotten, just look at the cost. Vikings could navigate with a stone. We need GPS. What goes with GPS ? A manufactory, powered by an electrical station. A satellite in the sky, that needs to be launched by a rocket, built by another manufactory, etc.

The 100-up exercise for proper running technique and posture

2011-11-08T08:55:00.000+01:00

Christopher McDougall, author of Born to Run, published a paper in the New York Times where, among many other things, he describes a good training to obtain a proper technique and a good posture: the 100-up exercise. With his talent as a narrator, he narrates how he digged up this secret, from W. G. George. Here is the description of the exercise:

The 100-Up consists of two parts. For the “Minor,” you stand with both feet on the targets and your arms cocked in running position. “Now raise one knee to the height of the hip,” George writes, “bring the foot back and down again to its original position, touching the line lightly with the ball of the foot, and repeat with the other leg.”
That’s all there is to it. But it’s not so easy to hit your marks 100 times in a row while maintaining balance and proper knee height. Once you can, it’s on to the Major: “The body must be balanced on the ball of the foot, the heels being clear of the ground and the head and body being tilted very slightly forward. . . . Now, spring from the toe, bringing the knee to the level of the hip. . . . Repeat with the other leg and continue raising and lowering the legs alternately. This action is exactly that of running.”

Here is Christopher McDougall showing how it's done:

He then published two blog posts related to injuries, posture and the 100-up exercise: the barefoot MD, in his own words, 100-up and the vampire bite (aka, plantar fasciitis).
Some interesting comments on McDougall's post:

The finest traceurs in Parkour

2011-11-05T08:07:00.000+01:00

How to train in Parkour, according to these amazing traceurs? Play, play and play.

High fat diet & digestion of pythons

2011-11-03T08:05:00.000+01:00

Interesting article to appear in Science this week reported in the National Geographic about the swelling of organs in pythons in the after-meal period. Reseachers shows that there is a link between blood high level of fatty acids and the swelling of organs. The purpose of this process is to speed up digestion. The remaining question is how lipids causes the swelling.

Demystifying paleo. An answer to the 5 failings of paleo according Darrin Carlson

2011-10-31T15:00:00.000+01:00

Here I address, one after the other and in good order, each of the 5 failings of paleo, according to Darrin Carlson (blogpost published a few days ago in Free the animal).

Concerning knowledge,paleoanthropology & the paleo diet (the first failing : we don’treally know what our ancestors ate, therefore we can’t use paleoanthropology toguide us in our dietary choices)

First, the argument as it is described by Darrin Carlson isambiguous. Is it an epistemological/psychological problem ? or anontological problem ? Is it a problem with the way we build our knowledge(the way we obtain our data, analyse it and interpret it) ? Or is it a problemwith the data (not representative, damaged by the time, incomplete, etc) ?Whatever it is, we can address it.

If it’s an psychological/epistemological problem, Darrin’sstatement is that we do not have the adequate tools to know with 100% certaintywhat we ate during the Paleolithic period.

If he uses the 100% certainty with a psychological undertone, it means that certainty is a property of belief where the subjectthinks that his/her belief is not amendable or is incorrigible. But we’redealing with scientific truth, not about opinions. Is not science about beingable to find counter-evidence, counter-argument ? With 100% certainty,science disappears, enters the dogma era. Do we want paleofitness and diet tobe ruled by dogma ? As far as I’m concerned, I know what my answer is.
If he uses the 100% certainty in an epistemicway, it means that the belief possesses the highest epistemic status. There areseveral definitions for this approach : indubitability, no mistake beingpossible, justification to the highest degree. The first two are psychological,so they fall upon my precedent remark. The problem with this approach is thatit is very restrictive. Only some mathematical truths, that we know we canexhibit each section of the demonstration, pertain to that category where everypart of a theory is known to be true. But paleoantropology does not demonstrate anything. It goes like any experimental science, from hypotheses toconfrontation of hypotheses to evidence and data. Thus, there could no morethan corrobated hypotheses. We are dealingwith defeasible theories (under better interpretations or precedently unheardof data), not with mathematical demonstrations. In other words, it’s not a failing because it’snever been its aim to produce 100% certainty. We just can’t expect to find100% justified truths from paleoantropology because it’s not its goal and it’snot in its power. 100% epistemic certainty is simply not relevant.

If it’s an ontological problem, Darrin’s statement is that wedo not possess the adequate and complete picture of what our paleoliticancestors ate : our findings are too small, damaged, etc. Indeed, we don’tknow if we have the whole picture. But more than that, we don’t know if we don’t.An agnostic posture is maybe healthier. Caution is the keyword inpaleoanthropology : make no more assumption that what can be obtained frominterpretation of accessible data, but no less. What we think we know isreliable, because it’s grounded on very carefully analyzed data ; but forthe other part, we really don’t know and won’t venture on that highly slippereyground. What I mean is that we don’t know if we have a good picture, but each piece of the puzzle wehave is quite good.

Second, the section of the argument when Darrin states that wedon’t have compelling enough data on paleoanthropology to advice people to gopaleo, may be flawed. The problem, according to Darrin, arises when we try toapply paleoantropology’s knowledge about our ancestors to build a contemporary scientificallyjustified paleo diet. It’s the classical Hume’s problem. Wecannot go from « that’s the way it is/it was », « that’s the waywe ought to do it ». It’s true, we can’t. It’s an unlogical leap of faith.But why would we want to derived logically the paleo diet frompaleoantropology ? I think we have to consider what exactly are therelationship between paleoanthropology and the paleo diet. Is paleo dietderived from paleoanthropology, like electronic and computing technology arederived from first order logic ? or, like quantum optics are derived fromquantum mechanic ? No it’s not. Why ? Because paleoanthropology’sability to make prediction is limited by its topic : what happened a long timeago and had disappeared. A paleoanthropology expert can make predictions aboutfeatures of humanity in the past, not in the present or future. The laws ofpaleoanthropology have a very precise range. Quantum physics is about what was,what is, and what will be. Logic is about what is sound according to a certainsystem of formal derivational rules and axioms, whatever are the otherconditions. A quantum optics expert will use general laws, relevant for manyand many conditions, to make predictions and explains aspects of optics. She/hewill consider objects of optics to be in the range of the general lawsformulated by quantum mechanics. The same goes for an electronic expert. Is itthe case in paleoanthropology ? Are paleoanthropological law’s structuresufficiently abstract to consider that nowadays humans fall in itsdomain ? On what ground ? I think a paleoanthropology expert is onlyable to make prediction about the past of humanity, about what we were 3millions years to 10 000 years ago. Biologically (the interbreeding criterion),we didnt change much, but from a evolutionary point of view (divergence of somemembers increased by isolation from the main population), we did change a lot.Thus the problem is not that we don’t know enough about our ancestors, but thatit cannot tell us what we are now and what we should do. It’s simply notrelevant, we are out of range in some way. A paleo diet is not an applicationof laws about the past human nature to nowadays human. It’s a diet grounded on,among other things, paleoanthropology, which means that a paleo diet borrowsresults of researches about what was humanity to offer arguments and evidencesin its favor. A paleo diet expert is like judge who uses paleoanthropologyresearches (among others) to ground his decision.

Conclusion :it’s not paleoanthropology’s purpose to tell us what we should do, but it canhelp us to ground our decision to go paleo. So no failing, but maybe adisappointment for those who expect paleoanthropology to be the new Bible.

Concerning relativismand the Paleo diet (failing 2 : there is a plurality of paleo diet, thereforethere is no One paleo diet).

First, formally, the argument is flawed. You cannot entailfrom the fact that there is several paleo diet, that none of them is betterthan the others. It’s like saying that there are many recipes in this world,consequently all of them must share the same gastronomic properties. Indeed, it’sconceivable that among the numerous variant of paleo diet, one (or some are) isbetter than others. We cannot exclude this possibility simply because the criterionto identify this better diet isn’t currently clear. The relativist argumentdoesn’t hold.

Second, of course, there is no ONE paleo diet, because thereis no paleolithic diet, but only a paleolithic lifestyle, the way humansexploited their environment with specific tools and technology and interactedwith each others. It’s a form of life where exploitation of any environment ismade by specific tools and technology. Nothing else. Yet environment ressourcesdiffer enormously one to another, this is why the resulting diets are notunified (even if the same technology was applied in each context). The result weredifferent if you were in Ethiopia or if you had migrated to Denmark or Australia.But does that mean that each resulting diet was equally adequate for themetabolism of the humans exploiting the ressources of different environment ?It’s very far stretched conclusion. I wouldn’t go that far, because they mayhave mutated to adapt to new environment constraints. On the other hand, weknow (studies show) that differences in diet have impact on health. So it seemsto me that it’s highly probable that some paleo diet are better than others,even if the question of identification is still without clear answer.

Conclusion :there is no magic diet for humans, but some are probably better than others.

Concerning the speed ofhuman evolution (failing 3 : we have evolved since the paleolithic, thuswe can incorporate neolithic food in our diet).

Indeed, we did evolve and still are. But that’s not the pointof John Hawks’ study. First, we have to distinguish between mutation (a changein a genome) and selection (a nonrandom process by which a biological trait isfixed and dominant in a population), and its link to growth of population :the whole point of his study is that there is a correlation between the growth ofthe population and the rate of mutations.And the higher the rate of mutation, the higher is the probability to findadaptive mutations in a new environment. But growth of population isn’t aselection tool. Thus the fact that we mutate a lot doesn’t necessarily implythat adaptive mutations are already fixed (dominant) in our species.

Second, there is the constraint of selection/mutationexclusivity to consider : the more selection you have, the less mutationyou can have (when the members of species reach the optimum adaptation to theirenvironment, then the space for mutation diminishes). Thus, with a newenvironment (opening of Neolithic era), and the sudden growth of population, wecan assume the gross rate of mutations in human species has increased, and thatit is highly probable adaptive mutations were selected. The study shows a hugeincrease in mutations, which means that the human body wasn’t at all ready forthis kind of new lifestyle, because it was optimally adapted to paleolithiclifestyle and environment. The room left to mutations was very narrow at thispoint. We have to bear in mind that, even if our mutations rate is 100 timeshigher than during the paleolithic period, Hawk’s study’s range, is millions ofyear. The neolithic revolution began only 10 000 years ago, which means that wemay not have finished adapting to the neolithic revolution, which happened nota long time ago, because it’s too short a time i) to produce several pools ofpopulations across the world who offer the adaptive mutations ; ii) tomake this adaptive mutation the dominant trait. And I’m not even talking aboutour modern, industrialized diet (there is no point to kid ourselves, what weeat today, even if we are careful, are domesticated species of wild plants andanimals. Even if you own your farm, you raise cattle, not aurochs. The samegoes for grains, legumes and dairy). Modern industrialized and processed foodappeared only a few decades ago, even if we are adaptating very fast, we areoutmatched. Maybe a few of us have mutated, but the advantageous genes cannotbe dominant at this hour.

Third, maybe some pools of human populations have evolved toadapt to a neolithic lifestyle and diet. By this I mean that adaptation to theneolithic lifestyle is or in phase of being dominant in certain humanpopulations. Darrin is cautious in this paragraphe, when he writes that,depending on our ethnic roots, some of us may have adapted to live the neoliticway. But we don’t know who. What we do know is that real-life persons’ healthis at stake. And I think it’s highly ethically dubious to encourage people toplay with their health, just because of the intuitive idea they have abouttheir ethnic roots.

Conclusion : weall evolved to live the paleolithic way (with variant according to thedifference in the environment), some (who ?) of us have also evolved tolive the neolithic way, a fistful of us may have also mutated to live theindustrialized way.

Concerning nature(failing 4 : we cannot claim that something is good because it’s natural,therefore we cannot claim i) that the paleo diet is good because it’snatural ; ii) that the produce of the neolithic diet and of our moderndiet is inherently healthy or unhealthy)

First, failure 4 mixes « naturalistic fallacy » (anexpression coined my the philosopher G. M. Moore to discuss a metaphysicargument in ethic) and « appeal to nature » (a way to use nature inthe premises in an informal argument). The purpose of Moore’s argument is toshow that there is no clear definition of the term « good », and thatit cannot be reduce to the of sensation of pleasantness (see Principia Ethica, §10sq). The purpose ofthe appeal to nature’s argument is to justify a idea, a value, a behaviour, byan appeal to nature ; or to criticize an idea, value or behaviour by its« unnaturality ». An appeal to nature falls under the fallacy ofrelevance, as it is described by Darrin.

Second, I don’t see the point of this tour de passe-passe, this rhetorical move. Expressions that canentail another expression necessarilysalva veritate are really rare, philosophersdoubt they are any. But the problem with Darrin’s statement is that it leads usto a dead-end, then leaves us here with no answer concerning the problem of therelation between paleo and nature. Why it is so that processed food aren’tinherently unhealthy or healthy to us ? that neolithic food aren’tinherently unhealthy or healthy to us ? Simply because what ishealthy/unhealthy is determined by the cost/benefits relation in anenvironment/organism interaction. For me, Darrin is tackling the problem fromthe wrong side : it’s not « Paleo is natural, thus we have to gopaleo », which is, as Darrin pointed it, a fallacy ; it’s« Nature was and is still in some ways paleo, thus we can go paleo ».And by nature, I mean the way humansinteracted with a precise of state of environment. Paleo was and is partiallystill a state of nature, but nature isn’t a state of paleo, that is why youcannot entail that something is good because it’s paleo, or not good becauseit’s not paleo.

Third, the argument is flawed. It states that, because of thefallacy of the appeal to nature, we cannot say that neolithic andindustrialized food are inherently healthy/unhealthy. We cannot tell that theyare inherently healthy/unhealthy for the reason I exposed before. But I thinkwe do can tell whether they are healthy or not relatively to our organism, becausewe don’t always need an appeal to evolution to know that something is good/badfor us. Darrin’s argument is a kind of strawman : it assumes that in someway, hypothetically, there exists a knowledge of the absolute quality of food,then refutes it. OK. But, in what way does it concern us ? Do we need thistype of knowledge ? If we are talking about our health, we are talkingabout the health of members of the human species at some point in history. Dietary knowledge about health is always a relation between the ingerable things and ametabolism in a certain state.

Conclusion : don’tmake a strawman to make up false failing of paleo, find the true weaknesses andaddress them.

Concerning nutrionism,science and individual intuition (failing 5 : the science of nutritionismis young and foolish, it may not be the best way to ground the paleo diet)

Darrin Carlson advises us to not let scientific studies to bethe only guide of our diet. But see the following extracts :

« As it turnsout, recent scientific evidence suggests that, not only have we been evolvingsince the advent of agriculture, we are doing so at a rate that is about 100times greater than during the Paleolithic! […] From the standpoint of diet, itsuggests that many of us, depending on our ethnic roots, should expect tohandle the Neolithic foods of dairy, grains, and legumes much more effectivelythan others. » (From failure 3.)

« It makes a tonof intuitive sense that foods new to our diet are detrimental to our health.But from a scientific perspective, this observation is only the first part ofthe scientific method: formulating a hypothesis that must then betested. » (From failure 4.)

I totally agree with Darrin concerning the fact that we shoulduse a cross-disciplinary approach when it comes to build our diet, because someinadequacies may be corrected that way. What I don’t agree with is his« condemnation » of nutritionism, then its generalization to science.I’m not opposed to the idea that we can balance sciences’ suggestions by usingour own personal experience, but I find Darrin's use of science to back up some of his remarks (as in the extract), then his critic of science, and finally his advice that sometimes we have to trust science and sometimes we don't, without really without really telling us when we should and when weshouldn’t use science, a very disturbing moove. I don’t see any failure in that, except Darrin’sfailure to exhibit his criterion to chose between useful and wacky science.Nutritionism is young, consequently we cannot trust it ? What kind ofargument is this ? It has to be stronger than this. Imagine theconsequences of this argument in other contexts ! If nutrionism isscientific, it must answer to the standards of scientific and experimentalresearch, which prevent the « finding » of unsound results. If wehave to select between useful and wacky science, we need a good and clear criterion.Philosophers have debated for hundreds years about this and cannot find asatisfactory criterion. Darrin leaves us with our intuition. But intuition andobservation of intution have to be trained. What about for those who didn’ttrain ? And sometimes trained intuition fails us. No, we need acollective, shared criterion for that. Our intuition needs to be balanced. Andit’s not paleo’s role to tell us when science is whacky or sound.

Conclusion : somebad news : i) Paleo is not God, it cannot make a wacky theory into goodscience. But we already knew that ; ii) we don’t know yet how todistinguish good from bad science, but thankfully the standards for soundscience are more and more selective and reliable, thus science can partiallyguide us in our choices.

Coming back from thefuture to the present of paleo

I have no great insights about the future of paleo. But somethings worry me :

Paleo is a lifestyle, not a diet. We can’tstrictly eat paleo for a lot of reasons, we can only emulate it. But the dietis not the whole point of paleo, it’s about being adapted to our environment,whether be it social, physical or metaphysical. And it’s different than eatingmore steacks in a week.
Paleo is about building ethically, morally,physically fit and balanced individual, not following gurus. It’s good tofollow advices of people more advanced than us in that path. But if it goesagainst your ability to personally build your life, drop it. Follow trainerstimes to times, but take yourself in charge all the time. More and more guruswill come in that area, so beware.
Paleo is about finding happiness, not burdenedyourself with constraints or punished yourself for what you think are pasterrors. Paleo can change your life, this change can be powerful, but you have makepeace with what you are and what you did. Don’t let the comparison between yourcurrent paleo state crushes what you think you were, I’m sure you did greatthings.
Paleo is about finding what (I’m not saying who, that’s a whole other thing) we areas a species and as an individual, not about erudition. Paleo is an interestingtopic and it’s good to study the past and present of our species. But Paleo isa tool, and only a tool. If the tool becomes more important than the taskitself, it’s time to get some perspective.

“First they ignore you, then they laugh at you, then they fight you, then you win.” (Gandhi)

2011-10-23T08:00:00.000+02:00

It's one of the most powerful TedTalk I have ever seen. It's not about barefoot running or walking. But it's about listen to the skills of people ignored by others and about what matters. (Sorry I'm vague, but I don't want to spoil the whole thing). It's only 19mn long, and Bunker Roy is an amazing speaker.

Systema, femmes et self-défense

2011-10-21T10:15:00.000+02:00

Un article intéressant sur les femmes, le systema et le self-défense. Le systema n'est ni un art martial (un ensemble de techniques, de valeurs philosophiques et spirituelles destinées à aider un individu dans son cheminement personnel), ni un sport de combat (une préparation physique, morale et mentale pour une compétition en combat dans des conditions légales acceptées par les deux parties), mais un forme de self-défense (voir l'article sur Wikipedia sur le Systema, qui est assez bien fait). Le but est d'ouvrir les yeux des gens sur la réalité de l'agression (eux-mêmes, les agresseurs, l'environnement) pour pouvoir sauver sa peau en cas de situation de prédation. À titre d'exemple, voici une vidéo d'exercices de systema de défense au couteau où le scénario est: les deux individus ont un couteau placé dans leur ceinture:

Pour revenir au sujet qui nous intéresse, j'extraie quelques passages qui me paraissent intéressants:

Les gens cherchent à se protéger parce qu'ils sont effrayés. C'est justement la peur qui est la racine du problème. Généralement nous connaissons seulement la peur du point de vue de la victime potentielle. Mais la peur existe aussi de l'autre coté, l'agresseur est également effrayé. A présent vous êtes sceptique et je vais vous donner trois scénarios.
Un voleur veut votre montre.
1- Si vous êtes assoupi, il se faufilera, la dérobera et partira. Vous ne le sentirez même pas.
2 -Si vous êtes malade ou saoul, il pourra proposer de vous aider et prendre la montre à votre poignet ou bien l'arracher et vous pousser à terre.
3 -Si vous marchez dans la rue droit en pleine santé, c'est à peu près sur qu'il vous blessera. Il pourra vous sauter dessus agressivement, sortir une arme et si vous donnez pas votre montre, vous finirez blessé ou mort.
D'où provient l'acte d'agression du cas de figure ? De la peur qu'il n'arrivera pas à ses fins, que vous puissiez le blesser, le contenir jusqu'à l'arrivée de la police ou même le tuer. L'agression découle de la peur. [...] La source de ce besoin destructeur peut aussi être la peur ressentie par l'agresseur.

Un prédateur (j'exclue les cas d'agression dans le cadre de l'établissement d'une hiérarchie sociale) est un individu rationnel: le but de l'agression est d'obtenir ce qu'il veut de manière rentable: maximum de dégâts pour l'agressé et minimum de dégâts pour lui. Et c'est la peur que la prédation se retourne contre lui qui entraîne l'agresseur à choisir le moment où l'agressé potentiel est le plus vulnérable.

Un peu plus loin, sur les femmes, l'agression et le Systema:

L'art martial russe devrait être le choix des dames pour plusieurs raisons.
-Les traits uniques du Systema, tels que les mouvements naturels et la prise de conscience de ses propres forces et faiblesses permettent aux femmes de s'adapter rapidement même si elles sont complétement étrangères au combat.
-Les femmes peuvent progresser comme les hommes, elles progressent souvent plus rapidement que la plupart des hommes.
-Étant souvent plus menues et plus faibles physiquement que les hommes, les femmes vont trouver les principes de non-résistance et d'immersion dans le mouvement très naturel, alors que les hommes auront plus de difficultés avec cet aspect.
-Utiliser l'inertie pour manipuler le corps de l'adversaire n'est pas difficile pour les femmes. C'est le seul moyen pour qu'elles puissent travailler avec un grand gabarit.
-Une plus grande mobilité naturelle des tendons, la flexibilité et des mouvements gracieux sont des des avantages en Systema.
-De plus le Systema offre la liberté de découvrir les meilleures réponses à tout types d'attaques, permet d'apprendre à gérer la panique, à chuter et rouler sans dommages, à compenser le manque de force brute par des mouvements correctes et l'acuité, à améliorer sa conscience de l'espace, à éviter les endroits et les situations dangereuses...

Le Systema joue à la fois la carte de la psychologie (on fait face à ses propres peurs et aux limites de notre système moral: tomber, prendre un coup, faire mal à quelqu'un, la panique, etc) et la carte de l'entraînement physique. Les hommes sont souvent pris au jeu de la force. Les rites d'établissement de hiérarchie sociale, fondés sur la force (comme la monkey dance) sont très ancrés chez les hommes. C'est pourquoi, en cas d'agression ou de prédation, ils ont tendance à utiliser la force. Or, le prédateur a de nombreux avantages: il a choisi un environnement qui rend l'agressé vulnérable, il aura sans doute prévu une arme, avant même que l'agressé comprenne qu'il est une victime l'agresseur l'a déjà sans doute atteint plusieurs fois, etc. Un individu déjà atteint, vulnérabilisé, ne peut plus compter sur la force pour s'en sortir. Les premiers obstacles sont psychologiques : la panique (argh! j'ai été touché malgré mes 10 ans d'entraînements en karaté!), l'acceptation de prendre des coups, la volonté de croire qu'on va s'en sortir. Femmes et hommes sont concernés. Et ce n'est pas la force physique qui permet de dépasser ce genre d'obstacles.

Chasse à l'épuisement, running, & évolution de l'homme

2011-10-18T11:01:00.000+02:00

Version française de: persistence hunting and a hypothesis about human evolution.

Chasse à l'épuisement (persistence hunting), par un Bochiman du désert du Kalahari:

Ce documentaire est une partie de The Life of Mammals (2002), un film réalisé par David Attenborough, et produit par la BBC et Discovery Channel.

Quand j'ai vu ce documentaire pour la première fois, certaines émotions et idées liées à la course à pied, qui étaient jusqu'alors assez confuses, sont devenues claires et pleines de significations. Je savais déjà que la chasse à l'épuisement existait, entre autres grâce à la lecture du livre de Christopher McDougall Born to run et du livre de Bernd Heinrich Why we run, mais le fait de le voir a changé quelque chose.

Par exemple, je ne fais pas de tour autour d'une piste (un chien ne fait pas naturellement des tours de piste, s'il le faisait vous le prendriez pour un chien névropathe). Je ne vais pas juste courir ou jogger. J'ai besoin de me donner un but, imaginaire ou réel, et de me donner des obstacles à dépasser. Ce but n'est pas abstrait comme un temps, un rythme cardiaque, une distance, mais une action que je peux rapporter à la vie réelle: aller chercher quelque chose, quelqu'un, échapper à quelque chose ou quelqu'un, rattraper quelque chose...
Je pense que mon lecteur a vu Avatar, de James Cameron. Vous souvenez-vous du moment où Jake Sully vole pour la première fois avec son ikran/banshee ? Il dit : "I was born to do this (J'étais né pour ça.)." C'est exactement ce que je ressens. Je me sens né pour le faire.
D'un point de vue plus objectif, tout le monde peut observer qu'on est fait pour courir, que nous avons hérité de dispositions innées liées à la course à pied: des jambes longues, des genoux pour absorber les chocs, un talon pour stabiliser le mouvement, un coeur capable de changer de rythme en fonction de l'effort... Si nous avons toutes ces dispositions, c'est pour une bonne raison. C'est un outil de survie. Personne d'autre ne court comme nous courons, et c'est précisément ce qui nous donne un avantage dans certaines conditions.
Cette vidéo m'a permis d'expliquer certains comportements quand je cours. Par exemple, j'aime être silencieux quand je cours, si silencieux que même un chien ne m'entend qu'au dernier moment, qu'au moment où je suis si proche de lui que je pourrais le prendre avec mes mains nues.
Cela m'a permis aussi de rendre plus clair certaines expériences plus ou moins religieuses liées à la course. Dans la vidéo, le chasseur se met en transe pour atteindre l'esprit du koudou, se mettre à sa place, et retrouver sa trace. C'est typiquement une expérience religieuse de sortie de l'âme du corps.
Cela m'a permis de comprendre aussi pourquoi je n'aime pas tout ce qui peut interférer avec mon attention quand je cours, comme la musique. Courir, c'est être en interaction avec son environnement. Les nerfs sensori-moteurs sous les pieds captent des informations sur la nature du terrain et les transmettent, en retour, le système nerveux central renvoie des commandes pour adapter le comportement du coureur. C'est une interaction un aller-retour incessant entre le sol et nous-mêmes, via nos pieds. Pourquoi voudrais-je interférer avec cette harmonie ?
J'ai aussi compris la loi fondamentale de l'alimentation du coureur: il ne faut pas manger quelque chose avant de courir. Être à jeun est l'état naturel de notre corps, il sait le gérer (même si cette capacité se perd dans la société de surabondance qui est la nôtre). Un chasseur (quand son territoire n'est pas confisqué par des trafiquants ou des États non moins criminels) court non pas parce qu'il a un surplein de ressource énergétique à évacuer ou parce qu'il ne désire rien d'autre que les effets bénéfiques de la course à pied, mais pour manger quelque chose. Après avoir couru arrive le festin. Quand nous jeûnons, nous utilisons les lipides comme ressource énergétique. C'est ce pour quoi nous sommes faits. Se gaver de glucides avant un effort, c'est une erreur.

Qu'est-ce que la chasse à l'épuisement ?

La chasse à l'épuisement est une technique de chasse identifiée seulement chez les humains. Il s'agit de la manière la plus ancienne connue d'obtenir un gibier. Il semblerait que les hominidés la pratiquent depuis environ 2 millions d'années. Nous n'avons été qu'occasionnellement des charognards (occasionnellement parce que les autres charognards étaient avantagés par des dispositions de défense/attaque supérieures aux nôtres). Nous n'avons utilisé des armes que très tardivement (la lance est apparue il y a environ 400 000 ans et l'arc 30 000), et de toute façon, elles étaient au départ trop imprécises pour être utilisables en situation de chasse. C'est pourquoi nous avons pratiqué la chasse à l'épuisement.

Cette technique est une combinaison de course à pied et de traque. La traque servait d'une part à ne pas perdre de vue la proie, mais aussi à l'isoler du groupe auquel elle appartient. La course permettait évidemment de se rapprocher de la proie qui s'enfuyait, mais surtout de l'épuiser. C'est ce qui fait le coeur de la chasse à l'épuisement: on court jusqu'à ce que la bête meurt d'épuisement. Cette disposition est spécifiquement humaine. Si vous avez regardé la vidéo, vous avez remarqué que c'est un exploit à la fois physique et mental. La dimension physique est dans la poursuite, dans l'utilisation de ses mains libres pour transporter de l'eau et dans l'avantage résultat de notre système si particulier de thermorégulation: la transpiration. Mais il s'agit aussi d'un exploit mental : le chasseur brise la volonté de vivre de l'animal.

Il semblerait qu'actuellement, deux tribus pratiquent encore la chasse à l'épuisement : les Bochimans du Kalahari qui vivent dans la partie Sud de l'Afrique et les Raramuri (connus aussi sous le nom de Tarahumaras), qui vivent dans la partie Nord du Mexique. (Sur la photo, à gauche, l'ultramarathonien Scott Jurek, à côté du célèbre Raramuri Arnulfo Quimare.)

Comment chasser et pourquoi peut-on pratiquer la chasse à l'épuisement ?

Il n'existe pas de manuel pour la chasse à l'épuisement et ce savoir est quasi inaccessible. Certains chercheurs et coureurs contemporains forcenés ont tenté d'en faire l'expérience en utilisant le peu de connaissances dont ils disposaient. Voici quelques témoignages : Fair Chase, Persistence hunting part one, part two, part three, part four par John Durant. Il y a aussi quelques descriptions dans le livre de Christopher McDougall, Born to Run, de Scott Carrier, Running after the antelope (une version audio de son expérience peut être écoutée ici) et dans le livre de Heinrich, Why we run (pp. 128-132).

Pourquoi réussisons-nous à épuiser un animal à un tel point qu'il en meurt ?
Notre premier avantage est la transpiration. La transpiration est la production d'un fluide composé en grande partie d'eau, de minéraux et d'urée. Ce fluide est exécré par des glandes situées sous la peau. Chez l'espèce humaine, la transpiration sert à réguler la température: au fur et à mesure que l'eau s'évapore, la peau est refroidie. Les autres espèces régulent leur température en utilisant les glandes qui se trouvent dans la bouche en halètant. L'eau qui se trouve dans la cavité orale s'évapore, ce qui entraîne une diminution de la température du corps. Nous pouvons chasser jusqu'à l'épuisement total d'un animal, parce qu'en courant, nous obligeons un animal à constamment augmenter sa température, tout en réduisant son temps de récupération. Au bout d'un certain, sa thermorégulation n'est plus à la hauteur de l'effort. Il meurt d'un coup de chaleur interne. Une remarque pour terminer sur ce point. Beaucoup de personnes ne sont pas à l'aise avec l'idée de la transpiration. Je voudrais leur dire qu'il n'y a pas de raison d'en avoir honte, précisément parce que c'est ce qui nous donne un avantage incomparable. Certaines études montrent en effet (c'est une hypothèse parmi d'autres) que la raison pour laquelle nous avons survécu au réchauffement de la planète il y a 50 000 ans et aux conditions difficiles de la vie sauvage, contrairement aux autres espèces humaines qui existaient alors (comme l'homo neandertalis), c'est notre système de régulation de la température interne. Dans une compétition de chasse à l'épuisement, un homo sapiens aurait une proie beaucoup plus rapidement que son concurrent l'homo neandertalis.
Notre deuxième avantage est la bipédie. Les quadrupèdes peuvent se déplacer plus rapidement que nous sur une distance courte. Mais nous avons l'avantage d'avoir des mains libres, ce qui nous permet de transporter des choses. Par exemple, nous pouvons transporter de l'eau, ce qui nous permet de ne pas nous déshydrater complètement. Les autres animaux se déshydratent et ne peuvent lutter contre cette tendance en situation de chasse. Nous pouvons en revanche la stopper.
Un autre avantage est le rythme de notre course à pied. Voir (Bramble & Lieberman 2004). Ils ont comparé la distance parcourue par seconde en fonction des types d'allures pour des animaux <500kg (chevaux), des humains, et des quadrupèdes >65kg. Les chevaux sont très rapides quand ils galopent. Ils peuvent couvrir jusqu'à 11m par seconde, alors que les humains ne dépassent pas 10m ps. Mais il s'agit de la condition du sprint. Le point important est que les chevaux ne peuvent pas galoper très longtemps. Et quand ils ne galopent plus, ils trottent. Quand ils trottent, les chevaux parcourent jusqu'à 6m par seconde. Nous ne pouvons pas sprinter aussi rapidement que les chevaux, mais en revanche nous joggons plus rapidement qu'ils ne trottent. Nous parcourons 7m ps en joggant. Et nous pouvons tenir ce rythme pendant des heures (voir le graphique). Vous avez compris la tactique: un cheval chassé est effrayé, il galope et s'éloigne des chasseurs, puis, à cause de la fatigue, il trotte. Pendant ce temps, les chasseurs humains, distancés par le galop, reviennent à la hauteur du cheval. À ce moment-là, il regalope. Il s'arrête et reprend le trot, les humains reviennent à sa hauteur. Et cette action se répète jusqu'à ce que le cheval s'effondre parce que son état ne lui permet plus de galoper. Un autre point important du papier de Bramble et Lieberman: nous sommes plus rapides en jogging que les quadrupèdes >65kg (ce qui signifie que les hominidés non entièrement bipèdes n'ont probablement pas pratiqué la chasse à l'épuisement).
Notre quatrième avantage est le fait que nous sommes une espèce socialement très développée. Réalisée seul, la chasse à l'épuisement est perdue d'avance. Comme l'écrit Scott Carrier, les animaux sont des proies professionnelles. Elles connaissent les règles du jeu. Elles vont lutter contre la volonté du chasseur de les isoler en allant au milieu du groupe pour ne plus pouvoir être reconnue, les emmener dans des environnements avec des obstacles, etc, pour que tous les efforts des chasseurs soient réduits à néant. C'est pourquoi un chasseur a besoin d'autres partenaires. Pour porter plus d'eau, pour répartir les tâches, pour soutenir le chasseur qui va accomplir la partie finale de la chasse (de 2 à 4 heures de course à pied, après tout la partie d'isolement).
Le cinquième avantage est notre système respiratoire (Bramble & Carrier 1983). Avez-vous déjà observé un chat ou un lapin courir ? D'abord, les pattes antérieures touchent le sol, puis les postérieures. Pendant ce temps, le dos de l'animal est rond. À ce moment-là, les viscères remontent vers le diaphragme qui appuie sur les poumons. Ce qui provoque un rejet de l'air, forçant l'animal à exhaler. Ensuite, l'animal s'allonge après la poussée des pattes postérieures. Là, les viscères sont étirées, elles reviennent vers le bassin et la pression contre le diaphragme cesse. Un appel d'air dans les poumons arrive, l'inhalation commence. Plus le mouvement des entrailles est rapide, plus l'animal peut respirer rapidement. (voir Heinrich 2001, p. 98, 99, 111-119; McDougall 2009, pp. 214sq). Le mouvement ressemble au glissement de l'eau dans une baignoire. McDougall caractérise ce mouvement par "take-a-step, take-a-breath (un pas, une respiration)". Eh bien, cela ne correspond pas du tout à notre manière de respirer. Notre système respiratoire est déconnecté de notre foulée, nous pouvons faire plusieurs pas en inhalant et plusieurs pas en exhalant. L'avantage des autres animaux est qu'ils font une économie d'énergie: un seul mouvement suffit pour faire un pas et respirer. Mais parce que leur thermorégulation est articulée à leur respiration et à leur foulée, paradoxalement, plus ils ont chaud, plus ils doivent aller vite pour se refroidir... jusqu'à ce qu'ils arrivent à leur limite. Ce système ne leur permet pas de courir très longtemps. Aussi atteignent-ils leur limite très rapidement. À 40°, un guépard cesse de courir. Sinon, il meurt. Pour nous, aussi longtemps que nous pouvons transpirer, nous pouvons respirer.

Chasse à l'épuisement et évolution de l'espèce humaine
L'hypothèse de la course d'endurance et la chasse à l'épuisement
L'hypothèse de la course d'endurance soutient que certains traits identifiables chez les membres de l'espèce humaine peuvent être expliqués comme étant des adaptations pour la course sur longue distance. Sur l'article Endurance running hypothesis de Wikipedia, on trouve les aspects suivants :

Grande abondance de glandes servant à la transpiration, et fonction thermorégulatrice de la transpiration.
Des doigts de pied courts (les longs sont plus appropriés pour la marche) (voir Campbell et al 2008).
Des muscles glutéaux très développés.
La tendance des humains à participer à des événements running de longue distance comme les marathons et les ultramarathons.
Capacité à stocker les lipides (et à les utiliser comme ressource énergétique).
Difficultés à faire face à un régime de vie sédentaire (obésité, pathologies liées au diabète).

Je n'ai pas inclus la dernière car elle n'est vraiment pas claire (capacité à respirer par la bouche pendant la course? Qu'est-ce que l'auteur de l'article veut dire ?). Peut-être que les auteurs ont voulu dire que les homines sapientes ont une disposition aérobique (capacité à utiliser l'oxygène pour générer de l'énergie pendant un effort long) en plus de leur disposition anaérobique (capacité à utiliser des ressources énergétiques via une fermentation des saccharides -les sucres-, sans oxygène, pour un effort court). Il faut aussi ajouter (Bramble & Lieberman 2004):

Le ligament nuchal. Sa fonction consiste à stabiliser la tête quand un animal court. Les espèces animales qui courent (chevaux, chiens) ont ce ligament. Les espèces qui marchent, comme les chimpanzés, n'en ont pas. C'est un trait distinctif des espèces qui courent.

L'avantage en matière grise de la chasse à l'épuisement

Si vous vous êtes intéressé à l'évolution de la tête des humains, vous savez que sa taille a augmenté soudainement il y a environ 2 millions d'années. Cette implique deux choses: i) puisque le cerveau est un élément du corps extrêmement coûteux en énergie, alors cela signifie que les humains doivent avoir à disposition une ressource énergétique importante ; ii) certaines parties du cerveau sont peut-être plus développées (ce qui a peut-être pour conséquence une redistribution ou réorganisation des fonctions et de la structure) chez l'individu dont la taille du cerveau a augmenté par rapport aux parties du cerveau des individus de l'espèce dont ils dérivent et dont la taille du cerveau est inférieure.

Il y a 2 millions d'années les hominidés appartenaient à l'australopithecus genus (qui est apparu 3 millions d'années plus tôt, c'est-à-dire il y a 5 millions d'années). Parmi les traits distinctifs de ce genre on trouve les traits suivants : puissantes et grandes mâchoires, taille du cerveau assez petite, intestins très longs. Pourquoi ? Pour digérer des plantes particulièrement fibreuses, qui lui fournissaient la ressource énergétique dont il avait besoin. Mais il y a 2 millions d'années, c'est le moment de la transition entre l'australopithecus genus et l'homo genus, via homo ergaster et homo erectus, les premiers hommes parmi les hominidés. Qu'est-ce qui les différencie ? Un cerveau plus gros, des intestins plus courts, des mâchoires assez petites avec des dents pour déchirer, une position debout. Pourquoi ? Parce qu'ils avaient trouvé une nouvelle ressource énergétique. Laquelle ? La viande fraîche. Elle est plus facile à digérer que les plantes (qui n'ont strictement rien à voir avec les variétés domestiquées que nous trouvons dans nos assiettes), et contient plus, par unité comparable, de ressource énergétique qu'une plante. Comment avons-nous obtenu cette viande fraîche ? Par la chasse à l'épuisement.

Avec la chasse à l'épuisement les premiers hommes possédaient une ressource énergétique plus compacte pour combler les grands besoins du cerveau. (Liebenberg 1990), dans un geste audacieux, lie le sort de la chasse à l'épuisement à l'évolution de la culture moderne (art et science), mais puisque je n'ai pas lu ce livre, je ne vais pas m'aventurer dans ses hypothèses et ses conclusions. Remarquez tout de même que des études (Brower 2006; Leakey 1992, pp. 257-258) montrent que, contrairement aux membres de l'australopithecus genus, homo erectus et ses descendants les plus directs possèdent l'aire de Broca (région du cerveau requise pour la disposition du langage), et qu'une autre montre que les homines erectes furent les premiers à vivre en petite tribu d'une manière semblable aux chasseurs-cueilleurs modernes.

Bibliographie

Bramble, Dennis M., and Carrier, David R. (1983). Running and Breathing in Mammals. Science 219: 251-256.

Bramble, Dennis M. & Lieberman, Daniel E. (2004). Endurance running and the evolution of Homo. Nature, 432: 345-353.

Boehm, Christopher (1999). Hierarchy in the forest: the evolution of egalitarian behavior. Cambridge Mass.: Harvard University Press.

Bower, Bruce (2006). "Evolutionary Back Story: Thoroughly Modern Spine Supported Human Ancestor". Science News Online 169 (15): 275.

Campbell, Rolian, Lieberman, Daniel E., Hamill, Joseph, Scott, John W., Werbel, William (2009) Walking, running and the evolution of short toes in humans. The Journal of experimental biology, 212, 713-721.

Carrier, David, R.(1984). The energetic paradox of human running and hominid evolution. Current Anthropology, 25:4.

Carrier, Scott (2001). Running after Antelope. Counterpoint Press.

Heinrich, Bernd (2002). Why we run. A Natural History. New York: HarperCollins Publishers.

Leakey, Richard (1992). Origins Reconsidered. New York: Anchor.

Liebenberg, Louis 1990. The Art of Tracking: The Origin of Science. David Philip.

Liebenberg, Louis (2006). Persistence Hunting by Modern Hunter-Gatherers. Current Anthropology, 47:6.

Liebenberg, Louis (2008). The relevance of persistence hunting to human evolution. Journal of Human Evolution, 55: 1156-1159.

McDougall, Christopher (2009). Born to Run: A Hidden Tribe, Superathletes, and the Greatest Race the World Has Never Seen. New York: Knopf.

Persistence hunting and a hypothesis about human evolution

2011-10-18T11:00:00.000+02:00

English version of Chasse à l'épuisement, running, & évolution de l'homme.

Persistence hunting by a Kalahari bushman:

This video is part of David Attenborough's The Life of Mammals (2002), a nature documentary produced by the BBC Natural History unit with Discovery Channel.

When I first saw this documentary all sort of things came to my mind. I already knew that persistence hunting existed, thanks to Christopher McDougall's book Born to run and Bernd Heinrich's Why we run. But when I saw it, confused feelings and thoughts about running became focused.

I don't just run. I don't go around a track, I go everywhere, I try to find obstacles (anything in my environment), I give myself an imaginary or actual goal, that has something to do with real-life situation: going somewhere, finding someone or something, etc. I can't run if I don't have a practical goal. Not a time, a heart rate, a distance, or an energy consumption, I care not about them. But I need to give myself something to do. The hunter doesn't run randomly, he has a purpose.
I assume many of you have watched Avatar. Remember the moment where Jake Sully says that he felt he was borned to fly the banshees/ikran ? I get exactly the same feeling when I run. That I was born to do this. I feel right in place.
In a less subjective note, some things about what we are as a species made sense. I knew that we were built to run: long legs, knees to absorbe shocks, heart's ability to change its rythm, etc. I knew that if we had those, it must have been for a good reason. But there was the answer: it's a survival tool. Nobody can run like us, that's what gives us an advantage.
I remembered some playful tricks I usually do when I run, e.g., be silent while running, so silent even a dog can't hear me coming until I'm right behind him, so close I could catch him with my bare hands.
The transe of the hunter reminds of mystical and religious feelings and thoughts while running (e.g., when running in harsh conditions, I can't help but thinking that I'm doing a Man versus Nature contest; or the sensation of floating, as it is described by Marshall Ulrich in Running on Empty; etc).
I could understand my dislike of listening to music when I run or of anything that can cut me from my environment. Running is an interaction between your body and the world. Your nervous system gives information about the world through the nerves implantation in your feet, and your central system gives commands to your body to adapt to your environment. It's an harmony. Why would I want to interfere with that ? I need to be with myself when I run.
I understood right to the point a fundamental law of nutrition and metabolic functions: you don't need to eat before running. Starving has been (and is still in some part of the world) the normal state of our metabolic system. Hunters ran and still run (when their territory isn't destroyed or confiscated by whatever criminal groups or States), because they need to eat, not because they had some superflous energy to spend or because they craved the health benefits of running. After running comes the feast. While fasting, we use fats as an energy source. That's what we were designed by natural evolution to do. We don't need to eat that much and certainly don't need sport drinks or a specific athlete diet. Even in harsh conditions, we can survive and be a lethal weapon.

What is persistence hunting ?

Persistence hunting is a human hunting technique. It's the oldest known to man way to get fresh meat. Hominids seem to do persistence hunt since 2 millions years. We weren't scavenger (well sometimes we were, but very occasionally) because we weren't the biggest cat in town. And weapons came very late (spears around 400 000 years ago; bow and arrow 30 000) and were too unaccurate to be really useful. So we did persistence hunt. It's a combination of running and tracking. Tracking allows the hunters to keep track of the prey and to isolate it from the group. Running is not only to get close to the prey, but to exhaust it. That's the whole point of persistence hunting: run an animal to death. We can do that, we're the only species on earth that can run an animal to death. If you have seen the video, it's a 50% mental and 50% physical prowess. The hunter uses his perspiration and free hands's advantage. That's the physical part. But it's also a mental game. The hunter breaks the will to live of the animal.

As far as our knowledge goes, only two tribes seem currently to still practice persistence hunting: the Kalahari bushmen of the southern part of Africa (as seen in the video) and the Raramuri (also known as the Tarahumaras) of the Northern Mexico. (In the photo on the right, ultramarathoner Scott Jurek and the famous Raramuri Arnulfo Quimare.)

How to hunt and why can we ?

There is no persistence hunting manual. This knowledge is almost extinct. But some contemporary researchers and runners tried it. There are some online testimonies: Fair Chase, Persistence hunting part one, part two, part three, part four by John Durant. You can also find some description in Christopher McDougall's Born to Run, and Scott Carriers's Running after the antelope (an audio version of Carrier's book can be found here), Heinrich's Why we run (p. 128-132).

So why can we run a animal to death ? As I said, first because we possess the finest thermoregulation on earth, second, because our hands are free, third, because we are fast on long distance, fourth because we are a social species, fifth because our respiration is disconnected from our running movements.

Perspiration is the production of fluid that consists primarily of water and some chlorids. They are execreted by sweat glands in the skin of mammals. In the human species, perspiration is a thermoregulation system: as the water evaporate, the skin is cooled down. Other species thermoregulate using their glands in their mouth by panting. They evaporate the water in the oral cavity, which decreases the body temperature. So why can we run a animal to death? Because, in persistence hunting, we constantly increase his body temperature while reducing is recovery/panting time. At the end, his body cannot cope with the effort. They die of heatstroke. A lot of people are not comfortable with sweating during an effort. I would say to them that there is no reason to, because it's a matchless advantage. Some argue (it's an hypothesis amongst others) that the reason why we are alive and Homo neandertalis (a species, with strong, huge and highly sophisticated from a cultural viewpoint individuals) disappeared is that they could not cope with the global warming of Earth 50 000 years ago, because their thermoregulation system was not efficient enough. In an endurance running competition with Homo sapiens, we would run a lot faster than they were in long distance. We would get our prey long before they could.

Our hands are free, contrary to quadrupedes, thus we can carry thing, like water. Quadrupeds are faster than we are on short distance, we have an advantage with the ability to carry things. With water, we can refresh, replenish our stock of body-water. We can run an animal to death, because other animals can't cover the loss of water, they drain water faster than they can replenish their stock. We can stop this depletion.

We're fast on long distance thanks to our pace. See (Bramble & Lieberman 2004) They compared the stride lengths of humans and horses (quadruped <500kg). Horses are really fast when they gallop. They can cover up to 11m per second, while humans can cover up to 10m per second in a sprint. But the point is that horses can't sustain over a long time speed gallop. When they can't gallop anymore, they trot. When they trot, they cover up to 6m per second. We can't run as fast as horses, but at an average jog, that we can sustain for hours, we can cover up to 7m per second (see the graphic from Bramble & Lieberman 2004). You see the tactics: the horse is frightened and run for his life for a few kilometers. We run not fast enough to stay at his level, but to keep him in sight and compell him to gallop regularly. Then, meters after meters, we get closer and closer until he is tired enough not to be able to gallop anymore. Another point on Bramble & Lieberman paper: we are faster than quadrupeds >65kg (e.g. chimpanzees) at this game.

We're a social species. Alone, persistence hunting is a losing game. As Scott Carrier says it, animals are professional preys. They know their stuff. They will struggle against our will to isolate them, they will go in the middle of the tribe so that no one can recognize them, and that hunters' efforts are nothing but a waste of time and energy. That's why we need other humans. They will keep the prey isolated, carry some extra-water, etc, so that the runner can carry on his duty at the final point of the hunt (the last two or four hours of running). We can run an animal to death because we're an extra-organized species.

Our breathing technique is different from other species (Bramble & Carrier 1983). Have you ever seen a rabbit or a cat running? First, they anterior legs touch the ground, then the posterior. While they're doing so, their back is round. At this point, the guts are pushing against their rib cage and lungs, forcing the air to go out, the animal to exhalate. Second, they elongate, the guts are stretched, pushed back against the pelvis and pressure against the lungs stops. At this point, a call for air is provoked and inhalation begins. The faster the movement of the guts, the faster they can breath. (See Heinrich 2001, p. 98, 99, 111-119; McDougall 2009, pp. 214-). As McDougall puts it, it's a "take-a-step, take-a-breath" coordination. Well it's not the case for us. Our breathing is disconnected from our stride. We can do several strides while inhaling. The whole point of other species breathing is that they save energy, their technique does not require a specific movement for breathing, as we do. But because they cool down by panting, their thermoregulation is entirely locked to their breathing system. It's more economic but less efficient. Indeed, if their temperature is skyrocketting during an effort, it means that for decreasing the temperature, they have to pant more. But to pant more, they have to run faster. But if they run faster, their temperature increases! Thus, it's less efficient than the functioning of our breathing/thermoregulation system. Once a cheetah reaches 40 degrees (celsius), it refuses to continue. The system shut down, it stops running. If not it dies. Well, for us, as long as we sweat, we can continue breathing at heart content.

Persistence hunting and evolution

Persistence hunting and the endurance running hypothesis

The endurance running hypothesis states that some human features can be explained as adaptation for long-distance running. What are those features ? In Wikipedia's entry Endurance running hypothesis, you can find the following:

Hairlessness and an abundance of sweat glands, as a heat loss mechanism.
Short toes. (See Campbell et al 2008).
Large gluteal muscles.
Human aptitude for endurance events such as ultramarathon
Increased bodyfat.
Long legs with springy tendons (no tendons in walking species, like chimpanzees).
Intolerance of sedentary lifestyle, regarding obesity and diabetes related pathologies

I deleted the last one (ability to breath through the mouth while running), because it doesn't make sense. Maybe they meant that homo sapiens has an aerobic capacity (capacity to use oxygen to burn fuel during physical activities), that asks for breathing, required for any effort covering a long period (unlike anaerobic capacity -also possessed by hominids-, where the organism fuels on a biological process -anaerobic metabolism- by which saccharids -sugars- in the body are converted into fuel and lactate through a fermentation, in the absence of oxygen). And there's more to it (Bramble & Lieberman 2004):

The nuchal ligament. This ligament is used to stabilize the head when an animal is running fast. It's attached to the posterior tubercule of the atlas and to the spinous processes of the cervical vertebrae. Dogs and horses got this one. Walking species, like chimpanzees, don't. This ligament typically identifes a species as a running one (thus, not a walking species).

The brainy advantage of persistence hunting

If you study the evolution of the brain of hominids, you know that the size of the brain increased suddenly 2 millions years ago. An increase means that i) the individual with an increased brain size has to find new supplies to provide energy resources (because the brain requires high amount of energy); ii) some aeras of the brain are more developped in this individual (requiring perhaps a reorganisation of the brain) than in the brain of the members of the species from which it derives.

2 millions years ago, the hominids pertained to the australopithecus genus (who appears 3 millions years before, i.e., 5 millions years ago). His features were, among others, giant jaws, tiny brain, and very long intestines. What for? To digest fibrous plants. But 2 millions years ago, it's the transition between australopithecus genus and homo genus, via homo ergaster and homo erectus. What happened? Their intestines were shorter, they standed up, they had tearing teeth, and their brain became bigger. Why? Because they found a new energy source. Which one? Fresh meat. It's easier and faster to digest, and per unit, it contains more energy resources than plants (which differed strongly from the domestic species we know). How did we get fresh meat? Persistence hunting.

With persistence hunting, we could supply more energy resource to feed our brain. And the benefits were increased sophistication of our mind. (Liebenberg 1990) boldly ties up hunting and the evolution of modern culture, e.g. science and art, but I never actually read it. So I won't venture any statements on that subject. However, a study (Brower 2006; Leakey 1992, pp. 257-258) shows that, contrary to members of australophitecus genus, homo erectus and his most direct descendants possessed the Broca's area (region of the brain required for sophisticated and articulated language ability) and another (Boehm 1999) that they were the first to live in small band societies similar to modern hunter-gatherer groups .

Bibliography