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Sep 01

Big Question: What really is evolution?

Somebody once asked me that if evolution were real, then why didn’t monkeys in zoos evolve into humans to escape? I despaired for several hours afterwards. The person in question wasn’t a particularly religious person, so I can only assume that his or her views stem from a huge misunderstanding on the subject. Indeed, if the theory of evolution stated that animals could suddenly and dramatically change into another form to escape unfortunate circumstances, as the person mentioned above seemed to think, then I wouldn’t be much of a believer either.

People have been speculating about evolution for centuries. Even as far back as the Ancient Greeks, some of the best thinkers proposed that all animals, including humans, could descend from other types of animals. They said that the first human must have been the child of a slightly different animal, because man needs prolonged nursing to live.

Much later, at the dawn of the nineteenth century, French zoologist Jean-Baptiste Lamarck theorised that if an animal has to do the same task over and over again, its body will inevitably change to make the task easier. His example was that giraffes had once been short-necked animals that one day decided to reach higher into the trees for food. This meant, according to his theory, that the necks of giraffes would gradually stretch as they got older, and their offspring would also be born with long necks.

It was all complete nonsense, of course. Even if a giraffe did somehow manage to stretch its neck in its lifetime, its genetics would still be that of a short-necked animal and so its offspring would still be born with short necks. Think about it this way: if a human decides to stretch the lobes of his or her ears for the purposes of decoration, their children wouldn’t be born with such modifications, would they?

Nonetheless, the theory encouraged another scientist of the time to search for the right answer: Charles Darwin.

The Theory of Natural Selection

After a voyage around South America and visits to the now-famous Galapagos Islands, Darwin, like many before him, began to suspect that species were not fixed forever. He noticed that the different giant tortoises that lived on the different islands within the Galapagos chain had subtle variations, allowing each to be better suited to their particular environment. Though these differences were very small, Darwin wondered that if a whole series of minute changes occurred, over millions upon millions of years, then they might add up so that a species eventually took a new form.

We now know that genes within individuals sometimes randomly mutate, perhaps by exposure to radiation or just because of blunders by the gene-reading mechanisms of a cell. Most of these mutations are harmful and, if they cause premature deaths, are very likely to be exterminated. But if a mutation makes an organism more able to defend itself, and if that particular organism survives to breed, then the mutation is likely to be passed on to successive generations. And so it is that those individuals best suited to a particular environment mate, pass on their advantageous characteristics and become more widespread; animals with less useful features, meanwhile, face more difficulties, find it much harder to pass on their genes and are eventually weeded out. In this way, one species may naturally die out and another will rise to take its place.

Diagram: Elembis

Darwin only used the word ‘evolution’ once in his ground-breaking book, The Origin of Species, in the closing paragraph – he preferred to use ‘descent with modification’ instead – but it’s a word that we nonetheless struggle to use without thinking of him. At the time, his theories of evolution, particularly those that involved man coming from an ape-like ancestor, caused a great deal of controversy – and they still do. Although up to 80% of people in the UK today believe in evolution by natural selection, only around 40% of Americans do – and Turkey is even worse, with only 25% of people accepting it.

But going back to the person who asked me the question about monkeys in zoos evolving into humans, I calmly tried to explain, in the simplest terms possible, how evolution worked. I obviously failed miserably. To him or her, the idea of an animal going through a series of tiny, imperceptible changes that might, or might not, lead to the rise of a new species seemed less plausible than a species suddenly and magically transforming into another.

The only place where that process seems natural is in the world of Pokѐmon. It’s perfectly acceptable there.

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