For many years, I’ve known that archaic cranial features are retained, to various degrees, by all the races of Mankind. I assumed that it was simply luck of the draw, at least in most cases.
The brow-ridge always puzzled me. What is it about Europeans that caused them to retain the brow-ridge while Africans and most Asians lost it?
Recently, I found a video that might explain it:
Brow-ridges and sloping foreheads have advantages for hunting. People hunted everywhere, and they hunted everywhere at long range, so why would the brow-ridge have disappeared from black Africa? Watch this clip from the video for an answer:
I’m proposing that black Africans experienced more of a threat from other black Africans than from wildlife, even while hunting. Therefore, more visible facial expressions (smiling or a wink for example) did more to protect them from other black Africans than heavy brow-ridges would have benefited them during hunts.
I’m not referring to times of war. The threat from war seems to have been a constant wherever humans lived. I’m referring to interpersonal (non-organized) spontaneous violence – perhaps over a woman or the last piece of chicken.
I’ve travelled quite a bit, and I’ve asked many questions of people from around the world. Generally speaking, a smile is more important among Africans (speaking of encounters among strangers) than other cultures. I’ve personally experienced how valuable a smile can be in black Africa; it tells people you’re not a threat. Smiling involves the eyes as much as it involves the mouth. Clearly visible eyes make it easier for others to determine that you mean them no harm. Brow-ridges might not only hide a smile, but it might signal hostility by default.
In Europe, for the most part, only males have brow-ridges. They’re useful for holding one’s sunglasses over the eyes when not using them, but more importantly, it was mainly males who hunted. Upon return to the village, Europeans were presumably less likely to get killed by an otherwise friendly local than were Africans. Brow-ridges, at least in a reduced state, could remain in Europe. Women, being non-hunters, simply had no use for them. One could argue that facial signaling was important for European women as well, and this is why their brow-ridges disappeared. I’ll quote a random media source to bolster my point:
Evolutionary Perspectives
From an evolutionary perspective, smiling may have developed as a way to convey non-threatening intentions. In primates, baring teeth can be a sign of submission or friendly greeting. Humans, as social animals, likely evolved the smile as a means to foster social bonds and communicate goodwill. Infants, for example, begin to smile shortly after birth, a behavior that promotes bonding with caregivers….
African Cultures
African cultures, with their rich diversity, exhibit a wide range of smiling behaviors. In many Sub-Saharan African societies, smiles are an integral part of social interactions and community life. Smiling can signify warmth, hospitality, and social connection. For instance, in countries like Nigeria and Ghana, smiles are commonly used to greet others and establish rapport.
What of Australian Aborigines? They have massive brow-ridges, at least by modern standards – and they seem to be every bit as impulsive as Africans. It could be that their Denisovan genes contributed to this, overriding the risks and benefits I listed above. It could also be that their extremely sparse population density meant less interpersonal violence, but a much greater emphasis on hunting. I look forward to more informed insights in comments.
I present this hypothesis in skeletal form. My hope is that a real scientist, more knowledgeable than myself, will do further research – but not lose his job as a result.
