Eilidh Glassey examines a variety of ways in which our bodies have been sculpted by evolution.

The Human

Unlike many other species, recent human evolution through natural selection has slowed down. I mean, since we developed weapons and guns, nothing really eats or preys on the human weaklings anymore. We are also not a species that makes the male prove in battle that he is superior to the others and therefore the best mating material in the jungle, unless you are counting his dance moves in the Lizard. As we have the ability and technology to change our environment to suit our own needs, all due to the development of opposable thumbs (thanks evolution), we no longer need to drastically adapt to suit it. There is evidence, however, that in the past the human species has had to adapt quite readily to its environment. Skin colour changed depending on the climate to prevent vitamin D deficiencies from lack of sun and we lost our fur, this is thought to be to reduce the number of disease carrying parasites that lived in the fur of animals. We did still keep it on our heads though, possibly because this is the part of us most susceptible to sunburn.

We also received some other hairy traits from our primal ancestors. Goosebumps appear when we are cold in order to raise the little hair we have on our bodies. Although this has little effect now, back in the days when we had fur this would create a layer of insulation against the cold, helping to keep us warm. Also, the hair still stands up on the back of our necks when we are afraid. Again, when we had fur, this was to make us look bigger and more frightening to our enemies but this is no longer the case. Both of these functions are just as useless as the male nipple, which is created early in the early stages of development when all embryos are female, yet still continues to develop when the embryo is male even though it has no purpose whatsoever.

From this we can see there are still some issues with the human body that evolution is yet to sort out. After only having been standing on two legs for a short amount of time, a couple of million years, we still have a similar bone and muscle structure in our backs as our previous four legged primate self which is not strong enough to support a lifetime of standing on only two legs. Another hitch in the human body is a woman’s petite childbearing hips. The human brain, and therefore head grew a significant amount fairly recently but evolution couldn’t keep up creating problems in childbirth.

 

The Platypus

I didn’t really know anything about platypuses before researching for this article but after reading about them, I can conclude they are some sort of semi-aquatic mammal god with an array of hidden talents. Thanks to natural selection they seem to have picked up all of the best features from the different animal groups and are almost perfectly designed for their lifestyle. A platypus feeds underwater and to help with this has a flat bill with an electro receptor allowing it to catch prey without using hearing or sight. It has a beaver tail to help steer whilst swimming and duck-like webbed feet to swim faster, combined with claws and venomous spurs for protection on land where they burrow and sleep. Along with this they also have: all three middle ear bones like a mammal, a large vocal range like a bird, egg-laying capabilities like a bird (even though it also has a uterus) and the ability to nurse their young, which is the definition of a mammal. Overall, this is a pretty impressive species.

 

The Bat

This species baffles evolutionists because of their echolocation (biosonar), which allows them to feed and navigate despite their poor vision. A bat’s sonar is better than that of the US Submarine fleet, which is quite some development of nature. Other than its sonar abilities, the bat is also the only mammal that has the ability to fly. By studying the bone structure it can be seen that the bat is very similar to the bird: it’s bones are reduced, making them extremely thin and light, the cranium bones are fused to reduce weight and it’s muscles are also light. These all make the bat perfectly fit for flight.

 

Eilidh Glassey

 

Image by Doug88888