What causes allele frequencies to change during genetic drift?

Answer 1

Genetic drift is the spread of specific random variations throughout the gene pool in the absence of specific selection pressures. There's always random variation in the population, but there aren't always changes in the environment for the population to adapt to. So natural selection, in stead of moving the population towards adaptation, might select from that random variation to move 'sideways', as it were, to a state that's equally well-adapted to the environment as what came before, but different. As random variation may produce many variants that are, more or less, equally well-adapted to their environment, the direction of evolution that results is more or less random.

Answer 2

Both normal reproductive variation and natural selection affect genetic drift. The difference between adaptation and drift is that there are no significant increases of fitness associated with drift: drift is more or less random - still filtered by natural selection, but not driven by specific environmental changes.

Answer 3

Genetic drift is the spread of specific random variations throughout the gene pool in the absence of specific selection pressures. There's always random variation in the population, but there aren't always changes in the environment for the population to adapt to. So natural selection, in stead of moving the population towards adaptation, might select from that random variation to move 'sideways', as it were, to a state that's equally well-adapted to the environment as what came before, but different. As random variation may produce many variants that are, more or less, equally well-adapted to their environment, the direction of evolution that results is more or less random.

Answer 4

Because genetic drift is a totally random process. Think of a small population of beetles. Dominant brown and recessive green. Brown much larger than green in population. The usual background of vegetation and whatnot favors brown beetles, but something happens and the environment changes to favor the color green against it. Predators start taking more brown beetles and the alleles of green beetles are changing in frequency just because of this random change in background color.

Answer 5

because genetic drift is one of five elements cause evolution and when pops evolve that means allele frequencies gradually change.

Answer 6

An individual organism moves into a new population.

Answer 7

by lowering pollution