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Angela
20-08-15, 17:19
See:
http://www.archaeology.org/news/3552-150810-evolution-cooking-starches

"BARCELONA, SPAIN—Karen Hardy of the Catalan Institution for Research and Advanced Studies and her team examined archaeological, anthropological, genetic, physiological, and anatomical data, and argue in The Quarterly Review of Biology (http://www.press.uchicago.edu/pressReleases/2015/August/150806_qrb_hardy_et_al_paleo_diet.html) that carbohydrate consumption was critical to the evolution of the human brain over the past million years. Starch-rich plant foods, when cooked, make it easier to digest the glucose needed to fuel the brain and to support human pregnancy and lactation. Early humans may have started off cooking meat, but they could have added tubers, seeds, fruits, and nuts to the fire. People now have an average of six copies of salivary amylase genes, versus only two copies in other primates, which increases their ability to digest starch. Genetic evidence suggests that this increase in salivary amylase genes occurred within the last million years. The increase in the number of genes may have co-evolved with the ability to cook, and further accelerated the growth of brain size. To read more about early humans, go to "Our Tangled Ancestry (http://www.archaeology.org/issues/125-1403/trenches/1806-human-dna-homo-heidelbergensis-denisovan-lineage).""

This sort of makes sense, but I think the amount of carb eating must have varied widely by area. In North Africa the hunter gatherers ate a lot of carbs, particularly in the form of nuts, so much so that it rotted their teeth.
http://www.ncbi.nlm.nih.gov/pubmed/24395774

The Near East of the Natufian "sedentary" hunter gatherers would also have been blessed in the amount of plant life it provided. This is an interesting article about Ohalo II, a site in the Galilee, and the astonishing variety of plants that were consumed by the hunter-gatherers there. There was also an abundance of wild animals for hunting and fish in the Sea of Galilee, as well.
http://www.biu.ac.il/js/archaeo/ohalo.htm

However, I can't imagine that the mammoth hunters in the frozen north got all that many carbs, although by the Mesolithic the ice and the mammoths were gone, and so the hunter-gatherers seem to have been hunter-fisher gatherers who were more sedentary, so presumably nuts and grains and fruits would have been a bigger part of their diet.

Still, a number of recent papers do show selection in Europe for alleles relating to carbohydrate consumption during the transition to farming there, if my memory serves. So, as the proportions changed, some selection must have been going on.

Anyway, so much for the modern "paleo" diets. It all depends which "paleo" or "meso" or "hunter-gatherer" area is under discussion.

bicicleur
20-08-15, 19:59
don't forget, cooking makes food softer, especially meat
because of that humanoids didn't need the strong jaws predators have
that made it possible to grow larger brains in their heads

LeBrok
20-08-15, 21:45
Heat not only softens food but mainly it breaks down fibers, cell walls, and long complicated proteins and starches, sugars making it better digestible or digestible at all.
With same amount of gathered food one can feed more members of a tribe, more kids surviving, when this food is cooked.

Angela
20-08-15, 22:59
Good points...so cooking is a big part of not only our survival as a species, but contributed to our big brains as well. Totally makes sense to me...