Posted: Aug 11, 2011 9:26 am
Teague wrote:Considering much of the planet has a human presence, are there any books on whatimpact this is having on evolution as a whole or can we just regard our presence here as part of the whole? Would it be fair to say that where humans inhabit, we are stemming the evolution of other species by our presence (be that in agriculture, pollution, deforestation, urbanisation, etc)?
The only way to stop evolution (short of killing everything) is to turn off mutation, or at least to weed it out whenever it occurs. Evolution is a mutation-amplification process that can cause such spontaneous changes to become common or universal in a species by ongoing sampling error every generation; because new ones arise all the time, species can't stand still. A constant supply of new mutational variants keeps the wheels turning. If you could turn off mutation, by gradual degrees Life would "freeze": species would each crystallise upon their own universal DNA sequence.
Mutation is also the motor of divergence that creates biodiversity by speciation. By normal attrition, species would be lost with no replacement - exacerbated by of the loss of within-species variation and de facto mass 'inbreeding' - and one by one the lights would go out.
But with mutation providing fuel, you have a process that cannot be stopped, notwithstanding some dumb ape destroying diversity in domestic and wild populations at an unusual rate.