genetic diversity and natural selection Flashcards
what does lots of different alleles result in
high genetic diversity
what are alleles
different version of a single gene
how is genetic diversity within a population increased
mutations in the genes forming different alleles
different alleles being introduced into a population when individuals from another population migrate into them and reproduce. This is known as gene flow
what does genetic diversity allow
genetic diversity allows natural selection to occur
what is genetic bottleneck
an event that causes a big reduction in a population e.g. when a large number of organisms within a population die before reproducing
what happens to the number of alleles in genetic bottleneck
the number of different alleles reduces in the gene pool and so reduces genetic diversity
what do the survivors of genetic bottle neck do
the survivors reproduce and a larger population is created from a few individuals
what is the founder effect
the founder effect is a type of genetic bottleneck
the founder effect describes what happens when just a few organisms from a population start a new colony and there are only a small number of different alleles in the initial gene pool
what is the frequency of each allele like in the new colony
the frequency of each allele in the new colony might be very different to the frequency of those alleles in the original population —— for example, an allele that was rare in the original population might be more common in the new colony. THis may lead to a higher incidence of genetic disease
what can the founders effect occur as a result of
the founders effect can occur as a result of migration leading to geographical separation or if a new colony is separated from the original population for another reason, such as religion.
