Human Sub-Species, Races and Varieties – what are we to believe?

Probably all of us sometimes think of what is ‘race’? It constantly crops up in the news, in reports, on television, in daily life. How do we deal with that? Let me start with three personal episodes. I gave a seminar once on my research in Papua New Guinea and mentioned Polynesian and Melanesian races. A lady in the audience then interrupted me with the claim that according to the latest findings races do not exist and that “We are just one people; we are all human beings”. I politely replied whether she hadn’t noticed that amongst us human beings there are differences with regard to the shapes of the lips and eyes, the structure of the hair and colour of the skin, whereupon she remarked that these were variations which you’d find in any population on Earth. I kept quiet, not wanting to argue that molecular genetics can trace your ancestry quite well and that in the case of one of my daughters 50% of her ancestry came out as South Indian (which pleased her South Indian Brahmin mother tremendously). The other 50% (from me) were an incredible mix from a multitude of regions.

On another occasion I had teamed up with a New Zealander, who had had 40 years of experience as an ophthalmologist and in his years of practice never had seen a case of glaucoma in a Maori (though he had treated Maori for other eye ailments and approx. 18% of the population were Maori). I felt this fact and information we had obtained from Australia (Australian Aborigines also apparently never suffered from this amongst Europeans not at all rare disease) suggested that there were perhaps genetic factors involved and we applied for a research grant. At the interview, the project was well received and looked like being funded, when however, the last question and comment by one person of the selection panel shot it down. He reminded us and the other members of the panel that Maori would never allow the eyes of one of their deceased to be removed for research. So, where and how would we get our eye material for the comparison with people of European ancestry?

The third occasion was at a conference in Germany around 2010, when a professor announced that what was usually termed “races” in humans were biologically-speaking sub-species. In his defence I have to explain that he did not want to be misunderstood and seen his suggestion to be linked with what the Nazis had termed ‘sub-humans’. No, he pointed out that to a biologist populations that become geographically isolated from each other will see certain genes accumulate, ultimately leading to visible morphological or invisible physiological differences between the isolated individuals, (despite identical chromosome numbers) so that (given a chance) they may still be able to mate with each other and have viable offspring. On account of their morphological, anatomical and physiological differences, however, they would have to be treated as sub-species. For animals and plants that was an established category of classification and would free us from using the term ‘race’ in humans, he suggested. The term ‘variety’ (as with apples or white, brown and black poodle dogs) could then be applied to individuals in a sub-species that wouldn’t completely blend in. Needless to say, the professor’s ideas were politely listened to, but did not receive the support he had hoped for.

To say “we are all one” and argue that differences do not exist flies in the face of common sense. Nobody can dispute that on average Koreans are shorter than Europeans, that Inuit have adapted to a meat diet, Thai can’t digest milk well, Bantu look different from Tibetans, etc. Sure, some Koreans are tall, some Thai drink cow’s milk, but centuries of relative isolation and limited gene mixing has indeed led to differences in world populations, actually to an extent that certain afflictions and ailments are more common in some than in others. A student came to me in Jamaica once, and asked why snake bites affected people of African and European ancestry differently. I didn’t know. I also don’t know why Maori and Australian Aborigines don’t seem to suffer from glaucoma, why prostate cancer is twice the rate of Europeans in African Americans, why Indians suffer so often from heart problems or diabetes is common in Pacific Islanders. To explain all these well documented differences away with references to social background and unhealthy life-styles, in my mind, is unscientific. Pure races or human subspecies due to geographic isolation and a lack to interbreed with others do no longer exist, but that the history of past and long-term isolations has left its manifestation should not be ignored. And that it can include (in addition to visible differences) susceptibilities to certain ailments, foods, pathogens or coping with environmental stressors, is likely.

© Dr V.B. Meyer-Rochow and http://www.bioforthebiobuff.wordpress.com, 2021. Unauthorized use and/or duplication of this material without express and written permission from this site’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to V.B Meyer-Rochow and http://www.bioforthebiobuff.wordpress.com with appropriate and specific direction to the original content.

Chin up!

An encouragement that can apply only to human

My 1950s comic hero “Nick Knatterton” of the weekly magazine “Quick” had a pointed and obviously very tough chin. Massive but rounder chins were the distinctive features of the Australian and New Zealand comic strip heroes Barry McKenzie and Wal Footrot, and even though Hervé’s “Tintin” did not have a prominent chin, he certainly had one, because it is a unique feature of all Homo sapiens, big and small. The chin, actually a bony protrusion medically often referred to as “the mental prominence”, is already noticeable in the foetus, but it becomes more and more obvious during the growth phase of a human after birth. No primate ancestor, no other mammal than the human species, has a chin and this continues to puzzle scientists representing different disciplines to this day.

A number of theories have been put forward to explain this peculiar feature of our anatomy. One holds that the chin helps us to articulate, in other words to speak and that our tongue’s movements need to be supported from the extra bone. Although humans are the only species in which speech plays a very important role in communication and the idea that the muscles to move the tongue need an additional support structure in the form of a chin, may initially sound plausible, there isn’t much force involved at all to move the tongue . And if an additional bony structure were indeed needed, why not in the jaw?

Another idea was that the chin somehow evolved as an aid to reduce stresses occurring during chewing. But we almost certainly chew much less than chimpanzees and gorillas (our closest animal relatives), and they do not have a chin. And what about the idea that the chin evolved as an adaptation for sexual selection? That also does not make much sense, because both men and women have a chin and sexually selected traits like antlers or manes are usually restricted to one sex only. Another suggestion has been that the chin was the consequence of the humans’ relatively small faces and that it compensated the reduced strength of the human jaw. Hormone levels would then have played a role as well. However, remembering how my hero “Nick Knatterton” occasionally used his pointed chin as a weapon, could it not have had a function in defence since our faces are flat, our teeth are small, and biting is difficult?

Or, could what I had observed many years ago provide an explanation? When I was a student many years ago, I had a girlfriend who had this habit of clamping a book or something between her chin and her chest, giving her two free hands to rummage about in her handbag searching for keys, a pen, or glasses. In other words, the chin could serve as a holding device leaving arms and hands free to be occupied with other things. No other mammal uses its hands as extensively as humans. On an excursion with boy scouts I also observed how the leader was carrying firewood in his arms right up to his chin, with the latter firmly securing the wood pile: the wood resting on his two outstretched arms, the chin clamping the pile from above. Although I have never come across this functional explanation for the presence of the chin, I think it’s not too outlandish a thought. Afterall, if a predominantly bipedal species that uses its arms to carry and transport “stuff” can use a method that increases the chance that none of the “stuff” falls down or gets lost, why not make use of the chin? Those able to carry more stuff like food or wood might have had a better survival chance and thus more offspring to pass on the “chinny trait”.

© Dr V.B. Meyer-Rochow and http://www.bioforthebiobuff.wordpress.com, 2021.
Unauthorized use and/or duplication of this material without express and written permission from this site’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to V.B Meyer-Rochow and http://www.bioforthebiobuff.wordpress.com with appropriate and specific direction to the original content. 

biology zoology blog benno meyer rochow cave troglobites

Troglobites with Eyes?

Mr. Liddle solved that riddle

Our ancestors were troglodytes. They wore clothes of fur and lived in caves. To most people, however, the idea of living in a cave does not really strike them as terribly enticing: no sun, no flowers, no green plants, no breeze, no wide open spaces and always damp and cool. However, it is precisely the predictability of these conditions, their constancy, which are the characteristics of the cave habitat that work to the advantage of certain animals and make them actively search for caves to live in or even to embrace subterranean life on a permanent basis. —>—>