Following on from that Nature feature on human migration I blogged about a couple of weeks ago, is another interesting piece in Science provocatively titled: “Busting myths of origin.” It is, however, exactly as the title says: analysis of DNA and isotopes in bones and teeth is showing that most of the people of the world are the products of multiple migrations: there are no “pure” peoples of any kind, with the exception of a very few groups, notably the indigenous Australian Aborigines, who, largely through accidents of geography and circumstance, remained isolated from many other human groups for a relatively long time. Migration and mingling, it turns out, is the norm for our species.
There’s been a lot of study into how vertebrates colonised the land, conjuring up lovely visions of our fishy ancestors hauling themselves out onto the mud on stumpy proto-limbs, helped by exciting fossil finds like Tiktaalik. What hasn’t been studied so much is why. It seems obvious – whole new ecological niches to expand into, and a rich abundance of invertebrate life to eat…but how did the animals know this before they got there? Well it may have been because they had evolved eyes sophisticated enough to take a good look at the view… Continue reading
How much of human violence is innate, and how much of it is shaped by our environments? Are we a uniquely violent species? These are questions philosophers and social scientists have tried to answer for centuries. Now researchers have done an evolutionary comparison – and conclude that the rate of lethal human violence is six times that of the average mammal…but about average for a great ape.
I had one of those “I never knew that,” moments reading a paper in Science magazine this week, but, given that the research in question managed to get published in one of the top journals in the field, neither did lots of other people. The “that” in question? That sounds can alter the development of a embryonic bird to enable it to adapt to the environment it can expect when it hatches. Continue reading
I read a rather interesting paper recently looking at the development of the human female pelvis, from late fetal stages until late adulthood. (You can find the full text for free here). The paper describes itself as challenging the “obstetrical dilemma hypothesis”: this is the idea that there are conflicting demands on the human female pelvis: to efficiently walk on two legs, a narrow pelvis is better, but to have large-brained babies, and to give birth safely to them, a wide pelvis is better. What I also find interesting, however, is that it takes the subconscious assumption that a large, bony structure, such as the human pelvis, is relatively fixed in proportion once you reach adulthood: turns out that, for women at least, it’s not.
There’s a lot of science fiction books that ask the question “What is it like to be human in an alien world/society?” Recently, with the explosion in molecular paleontology that is taking place, I’ve found myself wondering what it means to be human in a world that was (once) full of other – well, were they humans?
This comes under the category of “pet hate”, I have to admit, but also it’s a question of getting the science right (more on that another time). Saying such-and-such an alien species is a mammal (or, worse, a reptile, because, you know, they kind of have scaly makeup) is plain wrong. Why? Because the definition of a mammal is not the one you learnt in school. It’s not “has fur or hair, gives birth to live babies, makes breast milk”. A mammal, like any other animal, is defined not only (or even most importantly) by its physical characteristics, but by its ancestors, that is, by its evolutionary history. Continue reading