posted on Nov, 24 2013 @ 07:13 PM
reply to post by Another_Nut
Successful mutations occur often, but they can't be defined when they occur. You can only determine if a mutation is successful (in evolutionary
terms) in hindsight, because evolution has no goal. If you are able to determine that a mutation is spreading through a population faster than by pure
chance, then you would suspect that it's a successful one. Of course, that means that you have to wait a number of generations.
It's usually easier to identify unsuccessful mutations, because the most obvious of those lead to rapid death and elimination from the population.
But if the mutation doesn't lead to a rapid death (or infertility), and can be passed down through a population, then time is the only way to tell if
it's actually successful.
Naturally, "successful" is context-dependent. For example, some of the most successful mutations we know of are the ones that cause sickle-cell
anemia. (There are several such mutations, which occurred and spread independently, further testifying to their success.) But SCA is successful only
in the presence of the malaria parasite; in regions where malaria is not common, SCA is a strong negative factor and is unsuccessful.
So identifying a "successful" mutation is really semantics. They're successful if they succeed. Mutations that at first glance may seem to be
(and may actually be) seriously negative, may actually be successful in a new context.