genetic drift due to bottle necking will have what effect on alleles:
It will cause only the rarest of the alleles to dissapear. The resulting population will be relatively healthy given that the population size is not so small that the species enters an extinction vortex.
3 steps of speciation:
3. Reproductive Isolation
Inhabiting different parts of the environment, they don't come together and can't mate.
Even if they come together they cant mate if they breed at different times.
Even if they breed at the same time they will not mate if they are not attracted to one another.
Even if they are attracted to one another, they cannot mate if they are not physically compatible.
Even if they are physically compatible, the embrio will not form if the egg and the sperm do not fuse properly.
Hybrid inviability or infertility
Even if fertilization occurs sucessfully, the offspring may not survive, or if it survives it cannot reproduce because it is infertile.
individuals of two population of the same species cannot interbreed if they live in different places