Gene flow is the exchange of genes between two separate populations. This is most often accomplished when animals or spores from plants migrate to a new area. Any time a gene is introduced into a population where that gene once did not exist, gene flow has occurred.
Gene Flow for Plants and Animals
Here are some examples of gene flow in the plant and animal kingdoms.
- A population of flowers on one side of a river transports pollen to the flowers on the other side of the river, producing offspring.
- Blue-eyed people from Sweden move to a small town in Mexico where people all have brown eyes. When they mate, some of their children now have blue eyes.
- Some birds with shorter beaks enter into a population of birds with much longer beaks, resulting in the hatching of birds with in-between sized beaks.
- A Maine coon cat is brought to an island where only wild tabby cats live. After mating with other cats on the island, some of the kittens have bushy tails and tufted ears.
- A bunch of women from West Africa, where malaria is present, mate with a group of Europeans. Their children are less susceptible to contracting malaria due to the presence of antibodies from their West African mothers.
- Rhinos from one herd move to a new area and breed with rhinos of a completely different herd.
- Pollen from trees is blown far, far away to a completely separate group of trees and pollinates their flowers, producing trees with genetic characteristics of each population.
- A man with very dark skin moves to a remote village in Eastern Europe, where most people have light skin. Their children and grandchildren show evidence of this genetic flow when some are born with dark skin.
- Several red foxes move into and mate with a silver fox population.
- Two lion prides meet in the Savannah and end up procreating, introducing genetic diversity to each tribe.
- Red parrots are brought on an expedition to a remote section of jungle with only blue parrots, introducing color variation into the gene pool of jungle parrots.
- Brown beetles enter into a community consisting solely of green beetles, creating offspring with greater color diversity.
- Seeds and pollen from conifers on one side of a gulch are blown high into the air, eventually reaching and pollinating trees on the other side of the gulch.
- Interbreeding occurs due to the migration of tall members of an African tribe to an area of South America where people are much shorter, making possible new combinations of genetic traits, including variations of skin color and height.
- A population of moths with a high frequency of white alleles enter a population of darker-colored moths. Over time, more and more white moths are born as a result.
- Tigers with enhanced sensitivity in the dark mate with a group of tigers with less sensitive eyes, allowing a greater population of tigers with enhanced eyesight to be born after a few generations.
Gene flow can shape and change ecosystems and species, which makes it very important to understand both for those who are interested in nature and for those who are interested in science.