Topic 7- Reproductive separation

Question 1

When does reproductive separation take place?

Answer 1

when changes in the alleles and phenotypes of some individuals in a population prevent them from successfully breeding with other individuals in the population that don’t have these changed alleles or phenotypes

Question 2

When does evolution occur?

Answer 2

the new species population must be genetically and reproductively separated from the pre-existing species population- When this happens, there can no longer be an exchange of genes between the two populations

Question 3

Give some examples of allele or phenotype changes that can lead to reproductive separation

Answer 3

Seasonal changes- different mating or flowering seasons, reproductive timings no longer match up
Mechanical changes-reproductive body parts no longer match up
Behavioural changes-changes in their courtship behaviours, meaning they can no longer attract individuals of the opposite sex for mating

Question 4

What can happen when two populations of the same species become reproductively isolated from each other?

Answer 4

can eventually become genetically isolated

Question 5

Describe genetic isolation

Answer 5

If the two populations are no longer reproducing with each other, then they do not interchange genes with each other in the production of offspring
Changes that occur in the allele frequencies of each group are not shared, so they evolve independently of each other, which can lead to the formation of two populations that are no longer successfully able to interbreed

Question 6

How does genetic isolation lead to speciation?

Answer 6

When the genetic differences lead to an inability of members of the populations to interbreed and produce fertile offspring