Different in degree or kind: higher metabolism (Introduction)

by David Turell @, Thursday, May 05, 2016, 23:54 (2885 days ago) @ George Jelliss

George: Thought this might interest you, but I see you got there already!
> 
> http://www.sciencemag.org/news/2016/05/humans-are-highest-energy-apes-making-us-smarter... - An other version of the same research: - http://www.nature.com/news/fat-lot-of-good-1.19845?WT.ec_id=NATURE-20160505&spMaili... - "We humans are a conundrum to physiologists when it comes to our energy use, because we seem to have evolved an ability to have our cake and eat it, too. Compared with our primate cousins, we breed more and have larger brains — both of which should sap our energy — and yet we live for longer. - "In experiments described online on 4 May, scientists took direct measurements of daily energy use in more than a hundred people and in all other known species of great ape (H. Pontzer et al. Nature http://dx.doi.org/10.1038/nature17654; 2016). Chimpanzees, bonobos, gorillas and orangutans all failed to keep up. Every human expended hundreds of kilocalories a day more than any other ape, and the difference is down to greater metabolic activity in our organs. - "In other words, humans have evolved to use more energy. We are the original consumer society: our increased demand for physiological energy is driven by our more efficient way of walking, the energy-dense foods such as meat and tubers we have found, and the methods of cooking we have invented and adopted. - "The unusually large energy budget of humans presents both an opportunity and a threat. For a start, it helps to power — and to explain the development of — our unusually large and concomitantly energy-hungry brains....But how we found the fuel to maintain such an expensive cognitive prize, where other primates have not, has long been a puzzle. - "Then there is the risk. To have a body that needs to be fed more just to exist is a dangerous strategy in lean times, just as use of gas-guzzling motor vehicles is considered antisocial in a resource-constrained world. - "The human culture of food sharing helps us to keep the tank filled. So too does what seems to be a uniquely human trait among the primates: the ability to maintain significant fat reserves as a contingency. .... We may curse its effects today, but human fat tissue seems to have evolved to protect us from ourselves and our unquenchable thirst for energy. It's true: those who struggle to keep those fat reserves under control really can blame their metabolism." - Comment: we re physically very different than apes to support that big brain and our upright posture.


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