Straight, curly, brown, blond, red – there are so many hair types that it’s easy to ignore the fact that our hair is actually quite weird. Yes, you read that right! We’re the only mammals who have hairless bodies, with hair covering only our head. Even if we find the answer to why we look the way we look, the reason behind why we have so many hair types would still remain a mystery! Scientists are only starting to turn their inquisitive gazes towards human hair, so here’s what we have so far.
Hair is made primarily of protein keratin. It can be preserved for thousands of years under the right conditions (like the 5300-year-old iceman Ötzi that got frozen in a glacier). His body, hair, and clothes were all intact, whereas in a wetter and warmer climate the hair survives for a few weeks only.
There are many different hypotheses as to why we lost all body hair, but the one on our heads remained. Some think it all happened as a kind of cooling mechanism that allowed our brain to develop further and become larger, while other scientists believe it was left on our heads to regulate body temperature when travelling long distances. Our ancestors might have shifted to hunting, but still there were predators out there that could easily wipe them from the face of the Earth. That’s why they had to hunt in the heat when all other predators were resting, hence, they lost bodily hair to evolution, having some left for heat regulation.
Surprisingly, there is no scientific categorization of human hair, despite what your shampoo bottle might tell you. To do that a real research of the human genome must be done and that is something that hasn’t happened yet. Tina Lasisi, an anthropologist from the Penn State University is working on a proper classification that will allow further studies of the human hair.
One of the questions she wants to answer is whether the tightly curled African hair turned out like this to resist the heat better or there’s some other reason to it. And does it actually mean that the thicker the hair, the better protection from heat it’s offering.
Very rarely hair can be preserved in a fossil, but when finds like that are made – they reveal a plethora of facts about our ancestors’ health and even behaviour. The oldest human hair ever found was in the fossilized hyena coprolite dating 200,000 years. That human hair told anthropologists that the humans lived in South Africa alongside big herbivores like zebra, kudu, and impala.
Not only hair can tell how people spread across the globe, but it can also reveal what their habits were! For example, archaeologists at the University of Chile took 56 mummy samples from the northern Chile, and analysed them using gas chromatography-mass spectrometry. The results revealed that from 100 BCE to 1450 CE people in the region have been smoking plants that contained nicotine.
Another study of 40 mummies found in Egypt, Peru, and Chile allowed to find out the levels of mercury in the world in the pre-industrial era. Of course, it was much lower back in the day. Scientists could also determine that the diet mattered. Chilean mummies had higher levels of mercury as they consumed sea products, while Egyptian had the lowest as they mostly relied on land animals for food.