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“Humans have been regarded as a species so dependent on culture and technology that cultural adaptation has replaced biological adaptation.” (2008 Stock)1)

“In combination, behavioural and physiological flexibility form a two-tiered defence against environmental stress.” (2008 Stock)2)

“Most of our non-genetic methods for mediating environmental stress depend on our access to the resources provided by agriculture.” (2008 Stock)3)
“Scientists have also found evidence for self-domestication in human skeletal remains. Based on what’s happened to animal domesticates, it’s predicted that skulls should have become smaller and more feminine looking (in both sexes) with reduced brow ridges. Indeed, that’s what a 2014 Current Anthropology paper found, which measured Homo sapiens skulls from the Stone Age to recent times, about 200,000 years of human evolution. These results agree with previous studies reporting that average skull — and by proxy brain — volume in Homo sapiens has decreased by roughly 10 percent in the past 40,000 years. ”
“The sustained selection for lowered reactivity among mammal domesticates has resulted in profound changes in brain form and function. The larger the size of the brain to begin with and the greater its degree of folding, the greater the degree of brain-size reduction under domestication.[12][42] Foxes that had been selectively bred for tameness over 40 years had experienced a significant reduction in cranial height and width and by inference in brain size,[12][43] which supports the hypothesis that brain-size reduction is an early response to the selective pressure for tameness and lowered reactivity that is the universal feature of animal domestication.[12] The most affected portion of the brain in domestic mammals is the limbic system, which in domestic dogs, pigs, and sheep show a 40% reduction in size compared with their wild species. This portion of the brain regulates endocrine function that influences behaviors such as aggression, wariness, and responses to environmentally induced stress, all attributes which are dramatically affected by domestication.[12][42] ” “Feral mammals such as dogs, cats, goats, donkeys, pigs, and ferrets that have lived apart from humans for generations show no sign of regaining the brain mass of their wild progenitors.[12][48] Dingos have lived apart from humans for thousands of years but still have the same brain size as that of a domestic dog.[12][49] Feral dogs that actively avoid human contact are still dependent on human waste for survival and have not reverted to the self-sustaining behaviors of their wolf ancestors.[12][50] ”


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sociology/evolution.txt · Last modified: 2021/03/01 22:35 by marcos