QOTD: Plenty of time for evolution

Quote of the Day:

Basically, what creationists argue is that the evolution of new genes is linear and sequential — there is no history, no selection, it works entirely by random replacement of the whole shebang, hoping that in one dazzling bit of luck that the entire sequence clicks into the right sequence, and then it all works. If that were the way the process occurred, then they'd be right, and evolution would be absurdly improbable and would take an untenable length of time.

Another way to think of it is a bizarre version of the hangman guessing game, where one person thinks of a word, and the second person has to guess what it is. In the normal version of the game, the second person guesses letters one by one, and they're placed in the appropriate spot. In the creationist version, you only get to guess a whole sequence of letters in each round, and you are only told if you are right or wrong, not which letters are in the correct position in the word. Not only does it become a really boring game, but it also becomes extremely unlikely that anyone can solve it in a reasonable amount of time.

Evolution does not work like that. It works in parallel, changing and testing each variant simultaneously in many individuals, and then selection for the most favorable subset of changes latches them in place, making the matching letters more likely to be fixed. ...

... To put some representative numbers on it, imagine a protein that is 300 amino acids long, made up of 20 possible amino acids, and I'm going to ask you to guess the sequence. Under the creationist model, you wouldn't even want to play the game — it would take you on the order of 20³⁰⁰ trials to hit that one specific arrangement of amino acids. On the other hand, if you took a wild guess, writing down a random 300 amino acids, and I then told you which amino acids in which position were correct, you'd be able to progressively work out the exact sequence in only 20 log 300 trials, or around 50 guesses. - PZ Myers