isolated gene pools
Millions of years of evolution
Evolution in Mendelian Populations was created in 1931.
Rapid evolution occurs more often in small populations because genetic changes can spread more quickly without being diluted by a large gene pool. In small populations, genetic drift and founder effects play a significant role in driving evolutionary changes. Additionally, inbreeding in small populations can increase the chances of new genetic variations emerging and being fixed in the population.
Yes. There is no set rate for evolution; the speed by which populations diverge behaviourally, morphologically and genetically is determined entirely by circumstance. Even different genes in the same population gene pool can have different rates of evolution.
Yes, genetic drift has played a role in shaping the diversity and evolution of humans. It has influenced the genetic variation within different human populations over time. In small or isolated populations, genetic drift can have a larger impact on diversity due to random changes in allele frequencies.
Smaller populations or populations split by some sort of geographic barrier. In small populations gene flow and genetic drift would shift allele frequencies back and forth very rapidly as the population would be subject to the vagaries of the environment and the small size population effects of random effects and various sized gene flows into the populations gene pool. No selection for adaptive traits here and not enough allele shift for speciation., though enough for evolution If a large enough population is split, say by a river or mountain range, then you have different mutations offering up different selective opportunities and if these populations remain split long enough they may lose the ability to interbreed and become two different species. This without the wash out of diversity that would plague small populations.
Related organisms become less alike by divergent evolution, which occurs when two different populations from the same ancestor evolve in separate directions, leading to different traits and characteristics. Over time, natural selection causes these divergent traits to become more pronounced, resulting in greater differences between the populations.
Divergence in evolution refers to the process by which populations of organisms gradually accumulate differences over time, leading to the formation of new species. It occurs when ancestral populations become isolated or encounter different environmental pressures, causing them to adapt in different ways. Divergence is a key mechanism driving the vast biodiversity seen in the natural world.
Maurizio Salaris has written: 'Evolution of stars and stellar populations' -- subject(s): Evolution, Galaxies, Populations, Stars
It isn't. Evolution is just something that happens where you have populations of organisms. To any individual organism doesn't matter one hoot that its distant ancestor was different than itself, or that its remote descendants will be different again.
Evolution
Mutation, genetic drift and gene flow can all drive evolution to a degree and the last two, drift and flow, are especially powerful in small populations. But, the driver of adaptive change in all populations of organisms is natural selection.