Genetic Drift
The random selection of alleles passed down to offspring that can cause a trait to have no change, completely disappear, or become very prominent.
What is Genetic Drift?
A sharp reduction in population size and massive loss of genetic diversity caused by sudden extreme events like natural disasters or overhunting.
What is a Bottleneck Effect?
This genetic event occurs when a small number of individuals split from a larger group to create their own smaller population.
What is the Founder Effect?
When individuals produce offspring, the chance of passing on an allele contributes to genetic drift because it is completely this.
What is random?
Conservation attempts aided in increasing the American Bison population to this number, showing how a larger group is more stable genetically.
What is 500,000?
This historical human behavior is a prime example of how the Founder Effect heavily shaped modern genetic profiles.
What is human migration and settlement?
Genetic drift acts much more rapidly on this specific type of group, quickly reducing its genetic diversity over time.
What is a small population?
These specific, uncommon alleles are usually completely wiped out during a bottleneck event because future generations are limited to the traits of the few survivors.
What are rare alleles?
This specific religious community serves as an example of the Founder Effect in human history.
What is the Amish community?
Pure chance can increase the loss of these specific alleles, which are absolutely necessary for a population's survival.
What are beneficial alleles?
This marine mammal was thought to be extinct in 1892 due to hunting for blubber oils, until a bottleneck of just 20 survivors was found.
What is the Northern Elephant Seal?
This rare genetic disorder affecting bone growth and causing dwarfism became widespread in the Amish population because an original founding ancestor carried the allele.
What is Ellis-van Creveld syndrome?
Due to overhunting in the 1800s, this animal's population dropped to under 1,000, causing low genetic diversity where random chance caused some traits to become very common and some to completely disappear.
What is the American Bison?
Durham University research showed that elephant seals suffered a near-total loss of diversity compared to pre-bottleneck ancestors, compromising their reproductive genes and genes related to this hunting skill.
What is diving efficiency?
Over time, the extreme genetic isolation driven by the Founder Effect can lead to this major evolutionary event—the creation of an entirely new species.
What is speciation?