domingo, 18 de diciembre de 2016

Are the features we see in indigenous Africans proof of evolution since apes and homo sapiens originated from the continent?


I'm gonna try to pretend that this is a serious question, rather than just somebody looking for confirmation of their racism.

The problem here is a classic case of confirmation bias. You sought out "African" features that looked ape-like to you, but (to be blunt) that's wildly wrong about both apes and Africans. And more to the point, you didn't look further to see what features other "races" have that also look like the apes.

For example: under the fur, most chimpanzees have pale skin rather than dark skin. Dark skin is an adaptation for Africans, and if we're totting up differences that makes them "more advanced" than pale skin.



Similarly, most Africans are not especially hairy. (More on that in a second.) Some African men don't grow beards at all. Apes have full body hair, a trait they share with more with "Caucasians" than with most "Africans". You'll also not that the ape's hair is fairly straight, more like a "Caucasian's" than the classically frizzy hair of an "African".

And that's the rub: they may all look alike to you, but even the highly racist 19th century ethnographers wouldn't think to lump all of "Africans" together. I put the racial terms in scare quotes because they're not used any more; they are remnants of badly oversimplified racial stereotypes.  TH Huxley, for example, attributed 5 different races to Africa (Bushmen, Africoid, Negrito, Melanochroi, Xanthochroi; plus the Australoids that most people would surely see as "black"). The African continent has more diversity than the others, because people have been living and evolving there longer. The same continent brings us both the shortest people in the world (Pygmies, under 5 foot) and some of the tallest (the Dinka). They diverge more from the "apes" than groups with less diversity.



And so on. As I said, once you look critically at features rather than through lenses seeking to confirm your preconceptions, the Africans look no more like apes than anybody else. They are, arguably "more evolved" than everybody else, rather than less, but the distinction is really meaningless. They are all human, exactly as human as everybody else, neither more nor less.




I don't know how many indigenous Africans you've seen, because to say that they're all of a certain type is hilariously incorrect. About 99% of human genetic diversity is in Africa, and that is proof that we evolved there. 

All non African humans evolved from a handful of tribes that left Africa tens of thousands of years ago, and are about as closely related to each other as second cousins in any African tribe. Often, non African humans are even more closely related than that.

The number of mutations that occurred after leaving Africa is pretty tiny. Skin pigment variations, thicker hair in parts of Asia, a handful of other peculiarities. Nearly every morphological variation that exists outside Africa also exists (ie has its prototype) in Africa. Eg, there are many African tribes with long noses, slim features, Asian eyes, etc. Do some reading!

Finally, humans and chimps split off about 2 million years ago. Most non African modern humans' ancestors left Africa after the last ice age. So 95% of our post-chimp (ancestor) evolution was in Africa, 5% of it since.



It has been claimed repeatedly that Negroids are in terms of homonization level behind Europids(Caucasoids) and Mongolids. This is often justified in terms of their cranial capacity and non-orthognathic jaw shape. In reality, there was a similarly strong intraspecific selection competition within the Negroid race spectrum – compared to Mongolids and Europids.

 Negroids have therefore – compared to Europids and Mongolids – Negroid-specific progressive tendencies. However, not all alike, if one compares the Nilotid type (relatively progressive), the Sudanid type (relatively progressive with primitivisms) and the classic Paleanegrid type (relatively primitive and infantile-reduced).
While interestingly the primitive variants have even more archaic gene variants (Paleanegrids, Bambutids, Sanids) than the (relatively to) progressive Negroid forms(Sudanids/Nilotids).


1.Forehead shape
Negroids have one for them typical neotenic-infantile forehead shape(doomed/high). Whereas significantly more on average, Europids have sloping/low foreheads in combination with brow bridge. Similar to early archaic Homo sapiens forms. Regarding the forehead shape, Mongolids are between Negroids and Europids.
Negrid > Mongolid > Europid
1. Homo neanderthalensis 2. Europid type 3. Mongolid type 4. Negrid type


2.Skin texture
Negroids have a smooth-shiny skin, facial features with soft lines and more subcutaneous fat in the facial area, often despite clear leptosome habitus and low body fat percentage. This is due to intraspecific sexual selection process, and thus a clear derivation from archaic homonids. Whereas these features among Caucasoids and Mongolids are missing or are not very pronounced.


The most closely related living homonids, chimpanzees have little subcutaneous fat, very relief-rich face, not smooth and shiny skin, etc.

3. Reduction of body hair
Progressive Negroids (especially Nilotids) are relatively slight hairy compared with Europids.
The less body hair is only partly a adjustment to climatic environmental conditions:
- Adaptation to extreme dry heat among Negroids
versus
- Adaptation to extreme cold among Mongolids, after which very strong growth of beard and body hair – in the context of transpiration and hypothermia – could have been selected negatively.
Primary sexual selection(‘attractive feature’) could be the decisive factor towards hairlessness among progressive Negroids.


4.Lip shape

Thin lips in combination with a wide oral fissure is a primitive feature. Typical of less progressive Europids (especially unreduced Cromagnoids) and Mongolids. Negroids, however, have voluminous lip shape and therefore deviate in a progressive direction.

Negroids
> Europids (Aurignacoids / reduced Cromagnoids & Taurids/ stronger infantilized Mongolids)
> Europids (unreduced Cromagnoids & Taurids) & less infantilized Mongoloids (despite variability: frequent occurrence of wide oral fissure in combination with thin lips)


5. Better suitability for bipedality
Homo sapiens has still not reached the optimum balance of the head on the spine, the optimal upright gait, and therefore many orthopedic deficits, particularly in old age.
But some race forms in this case are much more harmonious and have an higher hominization level than others. Especially primitive at this point is Homo neanderthalensis, he serves as a perfect example of a primitive body shape and posture in the genus Homo.
Posture and body’s centre of gravity of a chimpanzee and an human being:

Baboon and Homo Sapiens compared with respect to skull-balance. The weight that is needed to keep up the baboon skull is much larger

Nilotid man:

Negroids have in this regard a further hominization advance in comparison to other racial groups. Especially Nilotids have – regarding the way of walking, position of the head and its center of gravity, relative leg length (lower leg-thigh ratio) and posture – reached the top of hominization.
Similarly shortened calf muscles and a specific muscle fiber variant among certain West African Negroids (especially Sudanids/North-Paleanegrids) – important for explosiveness in sprinting – improve the bipediality – a feature of homonids – in comparison to Europids and Mongoloids whom lack these features.


Progressivity of the physique:
- Longer legs (longer lower leg in relation to the thigh)
– Higher body’s centre of gravity
– Shortened calf muscles
– Better positioning of the head
Negroids (especially Nilotids) > South-Aethiopids
> Europids (Aurignacoids) & North-sinid (progressive peak of the Mongolid race)
> Europids (unreduced Taurids & Cromagnoids) & Mongolids
> Europids (reduced Taurids & Cromagnoids)


6. The prominence of the eyeballs

Similarly Negroids differ – in comparison to Europids and Mongoloids – due to a basedowoid eye tendency from archaic Homo sapiens forms. More prominent, not deep set, large eyes were in intraspecific competition a sexual selection advantage among Negroids.

Negroids > Aethiopids > Europids (Aurignacoids & Taurids & reduced Cromagnoids > Mongoloids & Europids (unreduced Cromagnoids)

7.Increased women’s profile WHR (waist-hip ratio)
Greater sexual dimorphism among Negroids (especially Sudanids) compared to Mongolids and Europids in terms of women’s profile waist-to-hip ratio. Steatopygia is an extreme form of this feature and can be found among Bambutids and Khoisanids.


Interesting study about male preference in relation to women’s profile WHR comparing two different racial-ethnic cultural groups (Hadza men & American men):
Page on harvard.edu
This study indicates that the different preference of both groups(Negrid=Hazda versus mainly Europid=American) could be genetically conditioned.



Are the features we see in Caucasians, like big, protruding brow ridges and far more body hair than other races, proof of evolution since they may preserve primitive features of our ancestors while those in Africa and Asia evolved farther away from them?




(Source: quora.com)
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