Chimps on treadmill offer human evolution insight

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Chimps on treadmill offer human evolution insight

This very interesting because it gives new insight as to one of the reasons early hominids may have begun walking upright. Less engergy used for walking could be used for increased foraging or hunting.

 

It is also very cool because it has a local connection for me, one of the researchers is from Washington University in St. Louis. 

 


Chimps on treadmill offer human evolution insight
Mon Jul 16, 2007 5:17 PM ET

By Will Dunham

WASHINGTON (Reuters) - Chimpanzees scampering on a treadmill have provided support for the notion that ancient human ancestors began walking on two legs because it used less energy than quadrupedal knuckle-walking, scientists said.

Writing on Monday in the Proceedings of the National Academy of Sciences, the researchers said people walking on a treadmill used just a quarter of the energy relative to their size compared to chimpanzees knuckle-walking on four legs.

The scientists equipped five chimpanzees and four people with face masks to track oxygen usage and looked at other measures to assess energy expenditure and biomechanics on a treadmill.

Bipedalism is a defining characteristic of the human lineage and marked an important divergence from other apes.

Chimpanzees are the closest genetic cousins to people. They are thought to have a common ancestor with humans dating back anywhere between 4 million and 7 million years, depending

on the estimate.

Some scientists for decades have advanced the hypothesis that millions of years ago, human ancestors began walking upright because it used less energy than quadrupedal walking, gaining advantages in things like food foraging.

But there has been scant data on this notion, aside from a 1973 study looking at locomotion energy in juvenile chimps.

"This paper provides strong support for the fact that energy savings played a role in the evolution of bipedalism," one of the scientists, University of Arizona anthropologist David Raichlen, said in a telephone interview.

The chimpanzees were taught to walk on the treadmill both quadrupedally and bipedally, the scientists said.

"These guys are smart enough that they would hit the stop button on the treadmill when they were done. If they didn't want to walk on the treadmill, they'd just hit the stop button or they'd jump off," Raichlen said.

Raichlen, who worked with Michael Sockol of the University of California-Davis and Herman Pontzer of Washington University in St. Louis, said chimpanzees on occasion walk on two legs in the wild, but are not very good at it.

Overall, the chimpanzees used about the same amount of energy walking on two legs compared to four legs, but the researchers saw differences among the individual animals in how much energy they used based on their gaits and anatomy.

One, for example, used a longer stride and was more efficient walking on two legs than four, the researchers said.

They also looked at the fossil record of human ancestors and found anatomical features such as hind legs that might use less energy in locomotion, and pelvic structural changes allowing for more upright walking.

 


This article can be found here:

 

 

 Chimps on treadmill offer human evolution insight

 


Hambydammit
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Is it me, or is

Is it me, or is evolutionary science in a particularly fertile spell right now?  It seems like every time I turn around, I'm reading something that provides empirical data for old, untested theories, or that turns an old theory on its head.

Two things that are always sure to geek me out are new sociology and new evolutionary knowlege.

 

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Hambydammit wrote: Is it

Hambydammit wrote:

Is it me, or is evolutionary science in a particularly fertile spell right now?

Yeah, it seems astronomy and evolutionary biology have been taking some kind of steroids lately. Lots of new muscle mass to flex for the culminated knowledge. 


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BGH wrote:

BGH wrote:
Yeah, it seems astronomy and evolutionary biology have been taking some kind of steroids lately. Lots of new muscle mass to flex for the culminated knowledge.

Whew! I thought it was just me! Since I've been part of this site, I've noticed more reports, references, etc. but I just thought that was because I was more aware of it than before. I get such a thrill when I read or hear about something related to one of these fields and I understand it!!

Ya gotta love Wash U! Some amazing stuff going on over there. So...longer stride = better energy efficiency = better ability to follow food/water sources....makes sense.  Our ancestors were pretty ingenious.


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So they used chimps on a

So they used chimps on a treadmill to prove that fat asses were an inter-species phenomenon?

 

 


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wavefreak wrote: So they

wavefreak wrote:

So they used chimps on a treadmill to prove that fat asses were an inter-species phenomenon?

Actually.... now the chimps are paying gym membership dues, buying ipods and buying mineral water. The economy is booming. 


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jce wrote: Ya gotta love

jce wrote:

Ya gotta love Wash U! Some amazing stuff going on over there. So...longer stride = better energy efficiency = better ability to follow food/water sources....makes sense. Our ancestors were pretty ingenious.

Exactly, that is part of it. Conservation of energy to use for tasks regarding obtaining food and procreation was another benefit of walking upright.

Also, another portion of the theory is that when our ancestors came down out of the trees and were faced with the tall savanna grass standing on two legs enabled them to see over the grass. When portions of the species ventured out into the grass and separated from the other population they began to evolve more adept bodies for continuous bipedal locomotion. 


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I tried to explain that

I tried to explain that longer stride thing to my ex girlfriend.  She always used to bitch at me for walking too fast.  I told her it was science.  She seemed unimpressed.

Geez... all this mod'ing I've been doing over the last few days, plus at least two deep conversations on ontology... I'm afraid I can't construct a straight answer to anything right now.

 

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BGH wrote: This very

BGH wrote:

This very interesting because it gives new insight as to one of the reasons early hominids may have begun walking upright. Less engergy used for walking could be used for increased foraging or hunting.

    A suggested reason I came across in research (a long time ago) was due to the movement from the jungle to the savannah.  A new set of predators, with no trees to seek safety in; hominids had to develop upright posture to peer over the tall savannah grass in vigilance of potential threats.   

BGH wrote:

It is also very cool because it has a local connection for me, one of the researchers is from Washington University in St. Louis.

Cool indeed.  And given the high distribution of places of worhip in St. Louis, I'm sure chimps are never in short supply. 

There are no theists on operating tables.

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National Geographic

National Geographic recently had an article along these lines.  It also discussed the energy required for a chimp to walk upright versus a human and what that told about the reason for the shapes of our spine and pelvis. 

What I wish they would do an article on is how the Bonobo developed such an awesome group attitude and how we can mimic it. 

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zarathustra wrote: Cool

zarathustra wrote:

Cool indeed. And given the high distribution of places of worhip in St. Louis, I'm sure chimps are never in short supply.

Are you saying what walks out of places of worship on Sundays resembles what appears to be relatives of Curious George? LOL 


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Nero wrote: What I wish

Nero wrote:

What I wish they would do an article on is how the Bonobo developed such an awesome group attitude and how we can mimic it.

There is a theory.  It says that, because they don't compete with gorillas like their cousins the chimpanzees north of the river, Bonobo females browse in groups (unlike chimp females, who have to spread out to find food). 

This allows bonobo females to form alliances which, in turn, protects the females from bullying and domination by larger males.   The same phenomenon is observed in Japanese snow monkeys, who are also matriarchal.

So, the theory goes, in order to have reproductive success, bonobo males can't just bully or coerce females.  They have to be nice and altruistic and reciprocate and all that.  Over the last 800K years, those are the behaviors that have been selected for.

Thus the message for humans should be clear.  The less patriarchal we become, the more free love for everybody. Smiling

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Textom wrote: Thus the

Textom wrote:

Thus the message for humans should be clear. The less patriarchal we become, the more free love for everybody. Smiling

 

Does this mean I got to start doing the dishes?