A wise sage in the field of hair restoration is Dr. Richard Shiell, from Australia. He was kind enough to allow me to use some random thoughts on some evolutionary aspects regarding hair evolution in the human species. This was part of an email interchange between Dr. Shiell and others in the hair restoration community. I personally always find his scope of knowledge and his wisdom quite insightful.
Hair certainly traps warmth in winter and acts as an insulator from the sun in summer but is this why we have it on our heads? It is very much like the question of “what came first- the dinosaur or it’s egg” (birds evolved from a small species of dinosaur).
Do hairy people migrate to geographical regions where they feel more comfortable or do people with more body hair have an evolutionary advantage and better breeding potential in colder climates? Does this also explain why native tropical races have very little body hair? Neither of these points explains why the females of homo sapiens have very little body hair, whatever their “race”.
The Tasmanoids who were the first of the homo sapien groups to come to Australia about 50,000 years ago had curly/kinky African type hair and very little beard growth or body hair. Did they elect to go to Tasmania, which is colder than the mainland or were they pushed there by subsequent migrating groups known by their bone structure as the “Robustus” group (20-30,000 years ago). The current native Aborigines with their big beards and skinny limbs are known as the “Gracile” Australoids. They have been here since before the last ice age melted some 10,000 years ago. Early photos of these Australian mainland aborigines (before interbreeding with white settlers) showed that they had massive beard growth, no baldness and very little body hair, perfect for a hot climate. The three separate races were all presumed to come from where Indonesia is today and to have walked across when sea levels were much lower during the various ice ages in the past 100,000 years. America’s first humans arrived the same way across what is now the Bering sea.
“Global warming” (and cooling) is nothing new and it is the speed of the current warming and whether human interference with nature is contributing to the warming, that is causing so much concern at present. I will stay out of that debate as it is highly political and results of â€œscientific research” is being used freely and wantonly by both sides! I hope that we can keep politics and religion out of the current hair debate but suspect that matters of sex will be difficult to avoid.
I used to tell my kids to take notes at the beach. When you saw a guy with a hairy back and shoulders he would invariably have a bald head or a hairpiece. This holds true most of the time but there are occasional exceptions indicating that the gene for hairy back and shoulders must be close to the one for type 6 baldness but is indeed a separate gene. Both characteristics are responsive to DHT as we know but while it acts like a fertilizer for scalp hair it causes reduction of shoulder hair in many guys.
Humans seem to have had an obsession with scalp hair since the dawn of recorded history. I guess it acts as a source of sexual attraction to the females of the species like the tail feathers of the male members of the peacock and bower birds families. It is not as all-pervading in humans as it is with birds where the bower-bird male with poor display misses out on the ‘action” almost completely. Consequently the tail feathers have evolved to enormous sizes. Human males can start breeding long before they lose their hair so it gives them a chance to get established in a family unit and as a provider before this sexually attractive feature is lost.
Almost any anatomical feature can be singled out by the opposite sex as a source of sexual attraction. The labia majora were naturally enlarged in the African Hottentot women and the women enlarged them further by dangling weight from both sides to form what was known by the early white settlers as the “Hottentot Apron”. It is not recorded if the white males found them equally attractive but after 6 months in the outback of South Africa, I guess they started to look pretty good !!
In turkeys the combs and throat skin has developed to crazy proportions and of course the posteriors of some species of monkeys are grotesquely red and enlarged. The nearest example of prominent hair growth in mammals that I can think of would be the mane of the male lion. Judging by the shampoo advertisements on TV and in the glossy magazines, hair is still a potent source of sexual attraction in homo sapiens.