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Friday, 1 July 2011

The evolution of the human body

In order to be able to look at ourselves in the mirror and be able to answer the question "Why do I look like this?", we must look back to our ancestry and their lifestyle, over a very long period of time. For the purpose of this analysis, let's look at the human versus the neanderthal. Recently there have been found neanderthal genes within the human gene pool, but the two species are different enough to compare, yet not too different (human versus fly would be too different).

As you can see, the construction of the human pelvis and toes is different, and the human has less hair. This results in humans being able to run easily for long distances, in the detriment of short-distance running which we are worse at. We sweat better, so we can do more long-term effort. This feat is essential to better settlements, as we can discover a larger area with potentially better resources. It might seem counterproductive to not be able to run quickly for a short period, when it comes to hunting, but humans' strategy is to chase the prey for a long time until the prey is so exhausted that it gives up. Neanderthals on the other hand are much stronger, but hairier and shorter.

As can be seen in the photo above, the human female has a relatively narrower pelvis which improves running long distances, but in turn makes childbirth more difficult. Eventually though, as a result of our scientific advancements, this isn't a problem anymore because complications may be dealt with in hospitals.

The neanderthal here is able to obtain bigger prey. However, the trade-offs of the modern humans out-competed those of neanderthals, as they are now extinct while we are successfully populating the Earth. The concept that evolution means humans "came from" monkeys is not accurate. As you can see, the neanderthal is quite similar to humans. There have lived many other different cousins of ours, each with different adaptations. Out of all of them, we came on top. The ancestors of all Homo genii might have looked a bit more like monkeys, and their ancestors even more. But the key idea is that the differences between each stage are very small, like between humans and neanderthals, while the differences between whole evolutionary branches are huge, like between humans and most other animals (dogs, fish, birds).

Back to our human here, the construction of her shoulders enables better weapon throwing, while the Neanderthal could hardly throw weapons. Humans have smaller teeth, with their canines a lot less sharp, and the wisdom teeth gradually disappearing from the species (some babies are born without the ability to grow wisdom teeth at all). We cook our food to the point where it is nice and tender, and the use of huge canines simply isn't there anymore.

So next time you look in the mirror, come to think of why you look like that. It's not the image of god. Most evolutionary adaptations have important roles, such as less hair and communication. But there are some things about us that are either outdated, or simply without a purpose, like byproducts of evolution. These things prove that there is no intelligent designer up there, and that evolution itself isn't perfect either. Check back to find out what these things are!

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