It has been particularly useful in understanding how populations diverge and how reproductive barriers arise.

Races are social constructs, and are not separated by reproductive barriers, and so cannot be considered strains.

Such instability can also lead to rapid reduction of chromosome numbers, creating reproductive barriers and thus allowing speciation.

As would be expected by members of different species, there are some reproductive barriers between members of the primary and secondary gene pools:

Mayr's response to cases like these is that the reproductive barriers that are important for species are the ones that occur in the wild.

Study of the genetics involved in this reproductive barrier tries to identify the genes that govern distinct sexual behaviors in the two species.

However, if both species are free from the bacteria or both are treated with antibiotics there is no reproductive barrier.

Hybrids were rare, suggesting that there were some reproductive barriers between the two groups.

Philodendrons exhibit extremely few physical reproductive barriers to prevent hybridization, but very few natural hybrids are found in nature.

Species can diverge when a part of the species is separated from the main population by a reproductive barrier.