> From: [EMAIL PROTECTED] > In a message dated 2/3/2002 12:29:04 AM Eastern Standard Time, [EMAIL PROTECTED] writes:
> But this article just backs up my point that selection breaks down in > large non-isolated populations. > > I am unsure what you mean by this. In large non-isolated populations speciation is rare (Ernst Mayr) but selection pressures are always working. --- Sexual selection perhaps (the ugly ones don't breed). Lets take an example. Assume a population of say 5 billion people. This population is not-isolated, and there are no small enclaves (i.e. people can and do frequently marry people who are distant from them). The Average female is able to bear up to 10 children, with three being about average. Now assume this one female has a super-good-awesome-mutation, that allows her on average to have up to 200 children with the average having 100. The descendants with super-good-awesome-mutation will always only be a small fraction of the population (but they never get isolated and are always capable of interbreeding with average people). They will never overtake and begin to replace the average people. This is similar to a math problem I had in the eleventh grade: person A is putting $100 into an IRA account once a month (say 8% interest) thirty years later person B is putting $1000 into an IRA account once a month. When will person B's total accumulated IRA account bypass Person A's (they keep putting in indefinitely)? Never. The same thing happens in the population scenario, the better genes are in only a small fraction of the total population. The same reason that the six finger gene is extremely rare in the current population.
