Gene flow: details
The amount of gene flow that goes on between
populations varies a lot depending on the type of organism.
As you would expect, populations of relatively sedentary organisms are more
isolated from one another than populations of very mobile organisms.
|Lower rate of gene flow
Corn, which is wind-pollinated, may be unlikely to fertilize individuals
more than 50 feet away.
|Higher rate of gene flow
However, other organisms are able to distribute their genes much further.
For example, fruit flies released
in Death Valley were recaptured almost 15 kilometers away from the site
Gene flow has several important effects on evolution:
- Within a population
It can introduce or reintroduce gene versions to a population,
increasing the genetic
variation of that population.
By moving genetic material around, it can make distant populations genetically similar
to one another, hence reducing the chance of speciation. The less gene
flow between two populations, the more likely that two populations will
evolve into two species.