Loss of genetic diversity after a few individuals found a new population or numbers crash.
The sample of alleles in a few colonists or survivors is unrepresentative; rare alleles may be common or lost. Reduced diversity makes populations vulnerable.
Northern elephant seals fell to about 20 individuals in the 1890s and have very low genetic diversity today.
Loss of genetic diversity after a few individuals found a new population or numbers crash.
Founder Effect and Bottleneck is one of the 53 topics in Evolution. It is rated Advanced, so it suits learners who want specialist depth. Related topics in this area include Allopatric Speciation, Experimental Evolution, Selective Sweeps.
Cheetahs have a similar genetic uniformity from a past bottleneck.
Work through the Beginner topics in Evolution first, such as Evolution, Natural Selection, Charles Darwin, then return to Founder Effect and Bottleneck. Advanced topics assume the Intermediate vocabulary.
The closest topics to Founder Effect and Bottleneck are Allopatric Speciation, Experimental Evolution, Selective Sweeps, Speciation. Comparing them side by side is a good way to see how the ideas connect.
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Founder Effect and Bottleneck. To practise the whole of Evolution, use the Evolution quiz.
Founder Effect and Bottleneck: Loss of genetic diversity after a few individuals found a new population or numbers crash. Allopatric Speciation: Speciation after a geographic barrier separates populations, as with Darwin's finches on separate islands. Read both side by side and note what each one explains.
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Allopatric Speciation and explain the difference aloud. Finally, take the Evolution quiz and come back to this page for any question you miss.
Speciation after a geographic barrier separates populations, as with Darwin's finches on separate islands.
🦎 EvolutionLong-term laboratory studies, like Lenski's E. coli, that watch evolution happen in real time.
🦎 EvolutionA beneficial allele rising to fixation reduces nearby genetic variation through hitchhiking.
🦎 EvolutionThe formation of new species when populations diverge enough to become reproductively isolated.
🦎 Evolution