On 12 Apr 1995, Lawrence Pierce wrote:
> Just one quick question for any one with some experience in the
> field of evolution. Does adaptation occur at the individual level or at
> the population. I recently began achapter on evolution and am a little
> uncertain about the answer to this question. Any qualified answers
> welcome
You have just asked a classical question in evolutionary biology. Lamarck
thought that adaptation could occur at the individual level by the
inheritance of acquired characters. For example, a giraffe could stretch
its neck to get a lengthened neck, which could then be passed on to the
offspring. This is known to be false. Darwin thought that some genetic
mechanism would give rise to long- and short-necked giraffes and, if
natural selection favoured long-necked ones over short-necked ones, then
giraffes in the next generation would have longer necks. In short,
adaptation results from natural selection operating on a population
of homologous entities (e.g., individuals or alleles at a particular
locus) that possess characters with fitness-related variance.
Xuhua
