Human evolution: role of growth hormone receptor gene (Introduction)

by David Turell , Sunday, September 26, 2021, 18:52 (1152 days ago) @ David Turell

A confused article with a very narrow view:

https://phys.org/news/2021-09-gene-tied-growth-scientists-glimmers.html

A new study delves into the evolution and function of the human growth hormone receptor gene, and asks what forces in humanity's past may have driven changes to this vital piece of DNA.

The research shows, through multiple avenues, that a shortened version of the gene—a variant known as GHRd3—may help people survive in situations where resources are scarce or unpredictable.

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Here's the story the study tells: GHRd3 emerged about 1-2 million years ago, and was likely the overwhelmingly predominant version of the gene in the ancestors of modern humans, as well as in Neanderthals and Denisovans.

Then, "In the last 50,000 years or so, this variant becomes less prevalent, and you have a massive decrease in the frequency of this variant among East Asian populations we studied, where we see the estimated allele frequency drop from 85% to 15% during the last 30,000 years," says University at Buffalo evolutionary biologist Omer Gokcumen. "So the question becomes: Why? Was this variant favored in the past, and it fell out of evolutionary favor recently? Or is what we are observing just a blip among the complexity of genomes?" (my bolds)

The research provides new insights into the function of GHRd3 that may help explain why these evolutionary changes occurred, demonstrating that the variant may be useful in coping with nutritional stress.

"We think that this variant is beneficial where there are periods of starvation, which was the case for most of human evolution," says Gokcumen, Ph.D., associate professor of biological sciences in the UB College of Arts and Sciences. With regard to GHRd3's waning prominence in recent human history, he speculates that, "Maybe the rapid technological and cultural advances over the past 50,000 years have created a buffer against some of the fluctuations in resources that made GHRd3 so advantageous in the past."

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The growth hormone receptor gene plays a major role in controlling the body's response to growth hormone, helping to activate processes that lead to growth.

To study the gene's evolutionary history, scientists looked at the genomes of many modern humans, as well as those of four archaic hominins—three Neanderthals from different parts of the world, and one Denisovan. (All four had the GHRd3 variant.)

Comment: A very strange set of conclusions from this narrow study of one gene. Certainly my first bold is true. More food became available as more modern times appeared with a better food supply. The second bold covers the magical effect Darwinist scientists ascribe to evolution magically conducting its purposes. My point in this presentation is another observation about human height size: in 14th century England the doors were so short, modern folks stoop to enter them. American antique clothing from the 17-18 centuries produces the same short height results. So my question is with less activator genes around, what lead to our current taller heights? The activator's effect is the opposite.