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Rainforest life accounts for “evolution” of short stature in pygmies—twice?

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From New Scientist:

Luis Barreiro of the University of Montreal in Quebec, Canada, and his colleagues identified 16 regions of the genome associated with short stature in the Batwa pygmies of Uganda. They then compared these regions in 169 Batwa and 74 Baka pygmies from West Africa.

“In both groups, there was greater variation in those regions associated with being short, but no overlap between them,” says Barreiro. This suggests they evolved their stature independently instead of inheriting the same “pygmy genes” from a common ancestor.

The team thinks “pygmyism” offers and evolutionary advantage to those living in a rainforest because they can duck under branches more easily.

But pygmy societies (men under five feet tall) exist in many parts of the world, and

Besides the differences within pygmy populations, there are also some non-pygmy populations that face some of the same physical challenges as pygmies but haven’t evolved a short stature. For example, many human populations live in dense forests and experience regular food shortages, and yet these populations have larger body sizes.

Other theories include adaptation to low levels of ultraviolet light or to heat and humidity, and need to reach sexual maturity more quickly due to harsh living conditions.

In any event, the use of the term “evolution” suggests that the change is permanent. But is it? An interesting article in Scientific American in 1998 noted that humans as a group are getting taller:

Let’s use this basic operating principle of evolution to predict, retrospectively, the direction of change in human height if evolution were the cause of the change. We know from studies conducted in industrial England that children born into lower socioeconomic classes were shorter, on average, than children born into wealthy families. We also know that poorer families had larger numbers of children.

Given those initial conditions, what would evolution predict? The average population should have become shorter because the shorter individuals in the population were, from an evolutionary fitness perspective, more successful in passing on their genes. But this did not happen. Instead, all segments of the population–rich and poor, from small and large families–increased in height. Thus, natural selection, the process whereby differences in reproductive success account for changes in the traits of a population, does not explain why we are taller.

The change is generally accounted for by improved quality of life, which allows most people to reach their potential maximum height.

Question: Do pygmies who leave the rain forest start to grow taller within a few generations? If so, is it meaningful to talk about their stature a form of evolution, as opposed to an adaptation within a range of possible heights? One that varies with conditions because it confers no permanent change?

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In the book, Pygmy Kitabu, the author theorizes that the pygmies are the original ancestors of the different nations. They even have the story of a tree that God put in a garden, with forbidden fruit that the woman ate first. mjazzguitar
The biggest problem here I find is this evolutionary need by the so-called white intellectual elite to explain the the physical traits of other human beings who don't look like them. This even incorporates Dawkins bigoted view of Downs Syndrome people. The only thing diet accomplishes here is Phenotypic plasticity, not some other species. But the materialist cannot get past their presuppositional fleshly worldview to consider other humans who are not a part of the Euro genetic make up being of equal worth and value as themselves. Hence the need to categorize and and label others as they would any other type of animal which nothing but blind unguided pitiless indifference created forth. DavidD
In general, humans need reasonable amounts of protein when they're young to grow tall. Asiatics were traditionally much shorter than the European explorers. This has changed since WW2. I'd assume the same thing about the English lower class: by the mid-19th century they could afford more meat. MacDonald's is the great equalizer. Surprisingly, prior to the colonization of Central Africa by Europeans, there really wasn't any FOOD in the African jungles. The Europeans brought food plants and farm animals. See "King Leopold's Ghost". The Belgians are "credited" with killing half the population of Central Africa, which amounted to only about 10 million people. One would have expected the oldest communities of humans on Earth in the "lush" jungles to have substantially larger populations. mahuna
WD40 "Samoans weren’t “some of the biggest people on earth” before colonization. Spam and corned beef, combined with cultural beliefs and and a metabolism adapted to a diet of fish and taro lead to the current prevalence of obesity in Polynesian peoples." LOL and Chinese people have slanted eyes because their ancestors had to squint a whole lot during the Ice Age and so therefore evolved the modern slant eye. These people are not only pathetic, but some of the planet's greatest professional scientific racists and bigots. But then that's just following the lead of their great religious guru Darwin. DavidD
Samoans weren't "some of the biggest people on earth" before colonization. Spam and corned beef, combined with cultural beliefs and and a metabolism adapted to a diet of fish and taro lead to the current prevalence of obesity in Polynesian peoples. wd400
Where I live, it is illegal to kill a pygmy. Mung
I'm still waiting for evolutionists to explain why Samoans [tiny pacific island nation whose Airlines charge their extremely large population an flight ticket by the pound] who are some of the biggest people on Earth got that way on such a puny island nation. DavidD

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