> Scientists Discover Genes which Allowed for Dietary Adaptations in Early Humans - The Food Safety Company Scientists Discover Genes which Allowed for Dietary Adaptations in Early Humans - The Food Safety Company
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    Friday, 17 March 2017

    Scientists Discover Genes which Allowed for Dietary Adaptations in Early Humans


    The journey to mankind’s eventual domination of the various lands of Planet Earth was a long and arduous one, requiring countless structural, physiological, and behavioural adaptations along the way. Over an estimated 6 million years, our early ape-like ancestors gradually evolved into the modern day species Homo sapiens. It is believed that the first major adaptation, namely the shift to bipedalism, occurred around 4 million years ago, with more complex defining human traits such as increased brain capacity, heightened language capabilities, and the making and use of tools, evolving much more recently.

    Around 75,000-100,000 years ago (the exact timing is difficult to calculate), Homo sapiens began to migrate out of our ancestral homeland of Africa into other territories throughout Asia and later, Europe. With this shift in habitat came a major change in the diets of these early populations - a change to which their bodies were forced to adapt. The issue was only exacerbated further with the rise of modern civilisation and, crucially, agriculture.

    Now, researchers believe that they have correctly identified two genes which were vital in allowing our species to survive this massive change, by facilitating the consumption of new food sources encountered by the newly-displaced populations.

    The genes, known as fatty acid desaturase 1 and 2, or FADS1 and FADS2 for short, are involved in the digestion of fatty acids. As our species began to encounter more and more new and unknown foods, those with favourable variants to the FADS1 and FADS2 genes were able to digest these new foods and thereby flourish, while those without began to die out.

    Professor Rasmus Nielsen   - Img: berkeley.edu
    Professor Rasmus Nielsen, of the University of California, Berkeley, told MailOnline, “The authors who originally observed the pattern in Africa suggested that it could be caused by a switch away from a diet linked to marine sources and rich in animal fat, to alternative diets that allowed humans higher mobility, and could therefore be linked to the expansion of anatomically modern humans inside Africa around 60,000 to 80,000 years ago. 

    “The FADS genes seem to have been frequent targets of natural selection throughout human history as our diet has been changing as a consequence of new hunting or agricultural practices.

    “[The FADS genes] have changed in multiple ways in different parts of the world. Generally, we see selection favouring alleles associated with a diet rich in animal fat outside Africa, more so than inside Africa. Possibly, as modern humans move outside Africa, they encountered new opportunities for hunting large mammals.”
                                                                                          
    Variations in these genes are evident even today. The Inuit population, for example, have adapted over time to a diet rich in animal fat from sources such as walruses, seals and whales; in India and surrounding areas on the other hand, the genes have instead adapted to facilitate a largely vegetarian-based diet.

    Here in Europe, it gets a little interesting. The FADS genes of Europeans have been slowly shifting to adapt to a grain-based diet, but Professor Nielsen and his team believe that this process is far from complete.

    “Our paper shows that there has been a new transition in Europe, where the alleles associated with a more vegetarian diet have been favoured, likely due to the emergence of agriculture and the change to a more vegetarian diet,” Professor Nielsen said. 

    “We hypothesise that Europeans may be in the process of adapting to a diet rich in fatty acids derived from plant sources, but relatively poor in fatty acids derived from fish or mammals. The introduction and spread of agriculture in Europe likely produced a radical dietary shift in populations that embraced this practice.

    “Agricultural diets would have led to a higher consumption of grains and other plant-derived foods, relative to hunter-gatherer populations.”


    Sam Bonson

    Sam is an aspiring novelist with a passion for fantasy and crime thrillers. He is currently working as a content writer, journalist & editor in an attempt to expand his horizons.
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