Saturday , June 15 2024
Natural selection ensures the survival of a species, in one form or another.

Natural Selection: Still Going Strong

For me there has always been a huge flaw in the arguments condemning natural selection — the fact that it works. You can talk all you want about creationism, or intelligent design, but natural selection is based on plain and simple observation of nature at work. So many times the argument you hear from people is that, "I'm not descended from some monkey, God made me," which has little or nothing to do with natural selection. Even if it turns out that a Creator was involved with the design of the human species millions of years ago, it has nothing to do with whether natural selection as a process works or not.

For those of you who missed grade ten biology, I'll give you a little summary of how evolution works, okay? The first thing you have to realize is that it's all about genetics and errors in genetic code called mutations. Now don't go confusing mutation with the Marval comics title The X-Men version of mutants, because in nature a mutation can be something as subtle as a colour change in feathers or fur.

Mutations occur all the time in all species, but usually they have little or no impact on that species and the strain dies out because the carrier of that new genetic code doesn't survive, doesn't mate, or its progeny don't make it. But once in a while a genetic variation comes along that is able to do better in the environment it finds itself in than other members of its species.

Whether collecting food or hiding from predators, its deviation or mutation gives it a better shot at surviving and when it breeds, that gene is passed along to some of its offspring who in turn… well you get the picture. As this happens the members of the species who lack the mutation that either keeps them safer or allows them to eat different foods, start to die out because they can't compete and gradually that gene pool is effectively eliminated as the dominate one; hence the saying "survival of the fittest."

That was more or less the theory Darwin put forward after his infamous voyage on the HMS Beagle took him to the Galapagos Islands. Darwin's wasn't the only theory of evolution to come out of the 19th century. Jean-Baptiste Pierre Antoine de Monet, Chevalier de Lamarck proposed that animals would evolve because of their surroundings and that genetic changes would occur as they attempted to adapt to what was around them.

Unfortunately this theory doesn't stand up to close examination; what it implies is that a species notes a more efficient way of surviving and is able to change its genetic code at will. If this were the case don't you think humans would have grown an extra set of hands by now? How many times have you needed that in a multitude of situations?

As anybody who has studied evolution knows, Darwin came up with his ideas based upon his observations of the different species of finch on the Galapagos Islands. As he travelled from island to island, he made note of the different styles of beak that individual species had, and how they were particularly suited to the food source available to them. As the concept of evolution wasn't a new thing (ancient Greeks and Indian scholars had written on the subject) he had a body of knowledge upon which he could base his theorems.

It's interesting to note that the big dispute about evolution in the 19th and early 20th century did not revolve around whether it existed or not, but whether it was caused by, as Darwin postualted, hereditary means, or as Lamarck said, by adaptive means. As research into genetics grows more sophisticated, including the discovery of DNA, it's become more and more obvious that Darwin's theory of inheritated characteristics caused by mutations is the correct explanation for evolution.

Recently there have been renewed attacks on the theory of evolution by religious people who don't want to accept that anything but the hand of God could have gone into the making of the world. They call themselves Creationists for the obvious reason that they believe everything was created by God.

A third alternative, intelligent design, has been offered up to explain evolution and other "unexplainable" natural occurances. Proponents of this theory claim that certain things are just too sophisticated to have occurred all on their lonesome and that there has to  have been some sort of intelligence behind those events.

Since they are deliberately vague about the nature of the intelligence – mainly because they want to keep religion out of it so that it will be accepted as science – it could lead sceptics like myself to wonder what they mean by intelligence. To me these sound like people who aren't honest enough to admit they are creationists, or embarassed by believing in God and are trying to make up science to justify their faith.

I have more respect for a creationist because they are honest about who they are and what they believe in. Besides if you have to justify or prove faith, doesn't that contradict the whole idea of faith? Oh well, I'll leave that for the theologists to fight over.

But just as all these theories are coming back into vogue at the expense of poor old Darwin, it looks like he's about to be rescued by his old buddies, the finches of the Galapagos Islands. It seems the little rascals went ahead and evolved again, while somebody was watching.

Peter Grant of Princeton Universtiy has been studying the Darwin finches of the Galapagos Islands for decades and had recorded the effects on drought and other environmental changes on the populations. From 1982 until the present, he was able to watch a smaller species of ground finch evolve to cope with the intrustion of a larger species that was in direct competition for its food supply. The larger bird was able to consume the shared food supply at three times the speed of the original inhabitant of this particular island. When a drought hit in 2003 and 2004, further reducing food stocks and increasing competition, the only birds that survived form the island's original population were ones with a smaller beak that could eat a different seed.

They are now the dominant strain of that species because of the mutation that caused them to be born with a different beak. If that second, larger species of finch had never shown up on their island, that mutation would either have made no difference and died out because they could not eat the large seeds easily. Instead they were in a position to survive rather than die out because of their genetic difference.

Natural selection at work – nature chose which was the version of the smaller bird that was more suitable for survival based on the circumstances at the time. A few years from now things may change again and a new mutation might be the one that becomes dominant. There is nothing evil or mysterious about evolution, Darwin, or natural selection. It's happening all the time all around you in many different species.

Most of the time it's far too subtle to make any difference, but sometimes, as in the case of the finchs of the Galapagos Islands, it ensures the survival of a species, in one form or another.

About Richard Marcus

Richard Marcus is the author of three books commissioned by Ulysses Press, "What Will Happen In Eragon IV?" (2009) and "The Unofficial Heroes Of Olympus Companion" and "Introduction to Greek Mythology For Kids". Aside from Blogcritics he contributes to and his work has appeared in the German edition of Rolling Stone Magazine and has been translated into numerous languages in multiple publications.

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