Pages

Monday, 13 November 2017

Evolution

I can't remember when I found out about evolution it was several decades ago, but when I did, it was "Yes, obviously that's how it happened".

But there's are lots of people, mostly religious, who have a very different understanding of evolution. What they call "evolution" isn't anything like evolution. They think that evolution is "One day, a cat gave birth to a rabbit". And they say "That's nonsense". And indeed it is. So here's what evolution is.

Consider rabbits.

The rabbits breed, have baby rabbits

And there are slight differences in the babies. Some have slightly longer hair, some can run slightly faster, and so on.

Some have better vision, some have worse.

The baby rabbits that can run faster, are more likely to survive; the slower ones are more likely to get eaten by wolves.

So over the generations, the rabbits get better at running.

Meanwhile, in another continent, there are other rabbits. And their problem is eagles.

Running fast won't help them unless the see the eagles fro a long distance.

So in this population of rabbits, the ones with better eyes survive

And in this population, the ones that are better at seeing upwards have an advantage.

So one population of rabbits gets stronger back legs that lets them run faster.The other population of
rabbits get better at seeing, because that lets them avoid eagles.

So after a million years, you now have two very different populations of rabbits

One has long, strong legs. The other has weak legs, but very good eyes, and can swivel their heads to look upwards.

And one day, someone gets a male from one population, and a female from the other, and discovers that they are
so different that they can no longer interbreed.

So we now have two species, different from each other. Leg-rabbits and eye-rabbits.

And that's how evolution works.

Here's a book I'd recommend.

No comments:

Post a comment