Welcome back to Science Sunday! (I seriously need to get a Bill Nye gif for this series...) Anyhow, how's it hanging with people? I do hope you are all having nice weekends! If you haven't had a chance to check out my current giveaway, may I suggest going here? And tomorrow I have some more awesome fun going on--a lovely cover reveal for THE CHEMISTRY OF FATE. I can't wait to show it off!!
Hmm, so I've been debating about what to talk about today. There's always lots of random stuff I'm reading about and talking about in lectures and since on Friday I was talking about Neanderthals being cold-adapted, well I thought that might be kind of fun :).
Okay, so, there's been a general trend in human body size/shape that's been noticed in most human populations. (It also works well in other species, too, but we'll stick to people for the moment.) People indigenous to areas around the equator (where it's usually much toastier than it is here right now--and yes, I'm totally jealous) are often taller and slimmer, whereas people closer to the poles tend to be more compact and have shorter limbs. It's been suggested that this distribution is because of adaptations to the environment.
What do I mean by that? Well, here's the thing: our bodies like to stay at a very specific temperature. 98.6 degrees on average. So, where the climate is hot, well people need to cool off better, and where the climate is cold, they want to conserve heat. Our bodies over many, many generations have been selected on to help either cool off or warm up. All of this has to do with surface area at its root.
|Same volume, but very different surface area!|
Of course, there are exceptions to this, and there's a wide range of variability in every population. And there are some populations who seem to be exceptions to the rule overall (some of which have recently migrated to where they currently live and haven't been there long enough for selection to work its power). Can you think of any exceptions?