Bio diversity is the range and apparent differences in living organisms. It is underpinned by differences in alleles.
Genetic diversity within a species can be explained using the term gene pool. This refers to all the genes and alleles within a population.
A broad genetic diversity is good because the population will have a greater number of difference alleles providing variation. This enables populations to cope with the changing demands of the environment.
Selective breeding is when you choose specific characteristics and breed the male and female that present these ideals. E.g. fast greyhounds. Unfortunately, selective breeding reduces diversity and therefore, the species chances of surviving change.
The Genetic Bottleneck:
Genetic bottleneck is when allele differences decrease and therefore diversity.
Original diverse population
Small subpopulation survive Allele frequency is not representation of original population
New – large population all descend from survivors
New population have lower allele frequency = decrease in genetic diversity = environmental vulnerability.