Which phenomenon can lead to loss of genetic variation and increase the probability of fixation of deleterious alleles in small populations?
Show answer and explanation
Correct answer: Genetic drift (bottleneck effect)
A population bottleneck — a sharp reduction in population size — increases the impact of genetic drift, which can randomly fix alleles (even deleterious ones) and reduce genetic variation.
Keep practicing
More Evolution and speciation questions
- Which outcome is LEAST likely if two populations remain in contact and continue exchanging migrants (gene flow)?
- Which process introduces new heritable variation into a population that can be acted upon by evolutionary forces?
- How can sexual selection contribute to speciation within a population?
- Which pattern of evolution describes the evolution of similar traits independently in unrelated lineages due to similar selective pressures?
- What does the term “reproductive isolation” refer to in the context of speciation?
- Which of the following best describes parapatric speciation?