09 April 2005

Evolution is inevitable

Things are bound to evolve if two conditions are satisfied:

1. There is a set of instructions (the genotype) that determines the morphology (the phenotype) of the things.
2. The instructions are copied and passed on to every new thing as it is starting to form.

These two seemingly innocuous conditions lead to evolution, because it is physically almost impossible to repeatedly copy of a set of instructions without -sooner or later- introducing an error. If anything, there is enough random, incessant thermal motion in the universe to mess things up, even if it is going to be one bit at a time. Once the genotype starts to change, the phenotype follows. And the rest is history.

That's it folks. Everything else follows from this. Natural selection? That is what happens when one phenotype is more successful in the present environment. That phenotype tends to stay around longer and is likely to leave more offspring. So, the successful phenotype soon becomes the dominant one until the environment starts to change and so on. But things could evolve even if natural selection didn't operate, although it would be hard to come up with a scenario without natural selection.

You can't avoid, pass up or ignore evolution. Well, I suppose if one tried hard and was foolish enough, one could ignore evolution and pretend that it was not happening. But once the environment has changed so much and you have been left behind to go extinct, there is usually no turning back. And no one will care enough to feel sorry for you. As Richard Dawkins1 said "nature is not cruel, only pitilessly indifferent."

1. Dawkins, R. 1995. Chapter 4 in River out of Eden. Basic Books.


deniz bevan said...

Actually that's really scary!!! because I'm so interested in philology, grammar, poetry, etc. and the way things are going - with all these media types who can't speak and everyone in real life picking up bad habits from each other - it looks like the whole English language is going to pot in an evolutionary way! It seems like there's more and more people every day who say such things as "did you write your paper yet?", or spelling all sorts of little words wrong in their emails, such as "well, than, I guess I'll go..." And if that's going to become the norm then people who care (me!) will soon become extinct!

Nix said...

Well, er, yes: languages do evolve, or, rather, diverge. There are few fitness criteria for language other than that human beings can speak, understand, and learn them, though, so selection pressure is, er, low.

There's a hypothesis that suggests that languages simplify when large numbers of people learn them as adults rather than children: e.g. English now, Latin in the time of the Roman Empire, and very possibly English around the time of the Norman Conquest, when English lost all that lovely Indo-European inflection and grammatical gender stuff. But simplification is not `devolution'; these languages are just as good as the ones that preceded them.

People have been complaining about the degeneracy of the English language and its ancestors for as long as they've existed. There's graffiti on 2000-year-old latrine walls complaining about that sort of thing. The world hasn't come to an end, and the English language is as expressive as ever.

“Our earth is degenerate in these latter days; there are signs that the world is speedily coming to an end; bribery and corruption are common; children no longer obey their parents; every man wants to write a book and the end of the world is evidently approaching,” attributed to an Assyrian stone tablet of about 2800 B.C. —-- William L. Patty and Louise S. Johnson, _Personality and Adjustment_, p. 277 (1953).

deniz said...

I'm not sure what this means: "There's a hypothesis that suggests that languages simplify when large numbers of people learn them as adults rather than children: e.g. English now..." - what do you mean by "learn them as adults"? Obviously everyone's learning them as children, as they grow up? I should think people learn a language only as adults when they've been conquered - like the Anglo-Saxons and Celts in England learning Latin during the Roman invasion, or French during the Norman Conquest, etc. No?