Related Experiment Video
Updated: Aug 8, 2026
08:51
Microinjection for Transgenesis and Genome Editing in Threespine Sticklebacks
Published on: May 13, 2016
Evolution: Selfing Takes Species Down Stebbins's Blind Alley
Jeremiah W Busch1, Lynda F Delph2
1School of Biological Sciences, Washington State University, PO Box 644236, Pullman, WA 99164, USA.
Current Biology : CB
|January 25, 2017
Summary
Selfing, or self-fertilization, limits a species' ability to adapt by reducing genetic diversity. A new snail experiment confirms that reduced gene pools hinder evolutionary potential.
Area of Science:
- Evolutionary biology
- Genetics
- Reproductive strategies
Background:
- Reproductive modes, such as outcrossing and selfing, significantly shape species' evolutionary trajectories.
- Selfing is hypothesized to restrict adaptive potential due to a smaller effective population size and reduced genetic variation.
Purpose of the Study:
- To empirically test the long-standing hypothesis that selfing limits adaptive potential.
- To investigate the evolutionary consequences of shifts from outcrossing to selfing in a natural system.
Main Methods:
- The study involved an empirical experiment using snails as a model organism.
- Comparative analysis of gene pools and adaptive capacity between outcrossing and selfing populations.
Main Results:
- The experimental results provide strong support for the hypothesis.
- Snails exhibiting selfing demonstrated a reduced capacity for adaptation compared to outcrossing snails, consistent with a smaller gene pool.
Conclusions:
- The findings validate the theoretical prediction that selfing constrains evolutionary adaptability.
- This study underscores the significant impact of reproductive strategies on long-term species survival and evolution.
Related Concept Videos
01:07Speciation Rates
Speciation can proceed at markedly different rates, and evolutionary biologists commonly describe these differences through the models of gradualism and punctuated equilibrium. Both patterns explain how new species arise, but they differ in the tempo and continuity of evolutionary change. In both cases, evolutionary change arises from heritable variation within populations, with natural selection often shaping traits that improve survival and reproduction under specific environmental conditions.
01:46Types of Selection
Natural selection influences the frequencies of particular alleles and phenotypes within populations in several different ways. Primarily, natural selection can be directional, stabilizing, or disruptive. Directional selection favors one extreme trait and shifts the population towards that phenotype while selecting against individuals displaying alternate traits. Stabilizing selection favors an intermediate trait with a narrow range of variation. Deviation from the optimal phenotype towards an...
01:21Frequency-dependent Selection
When the fitness of a trait is influenced by how common it is (i.e., its frequency) relative to different traits within a population, this is referred to as frequency-dependent selection. Frequency-dependent selection may occur between species or within a single species. This type of selection can either be positive—with more common phenotypes having higher fitness—or negative, with rarer phenotypes conferring increased fitness.Positive Frequency-Dependent SelectionIn positive...
02:16Genetics of Speciation
Speciation is the evolutionary process resulting in the formation of new, distinct species—groups of reproductively isolated populations.The genetics of speciation involves the different traits or isolating mechanisms preventing gene exchange, leading to reproductive isolation. Reproductive isolation can be due to reproductive barriers that have effects either before or after the formation of a zygote. Pre-zygotic mechanisms prevent fertilization from occurring, and post-zygotic mechanisms...
03:33Genetic Drift
Natural selection—probably the most well-known evolutionary mechanism—increases the prevalence of traits that enhance survival and reproduction. However, evolution does not merely propagate favorable traits, nor does it always benefit populations.Life is not fair. A deer grazing contentedly in a field can have her meal cut tragically short by a bolt of lightning. If the doomed doe is one of only three in the population, 1/3 of the population’s gene pool is lost. Random events like this can...
02:39Gene Flow
Gene flow is the transfer of genes among populations, resulting from either the dispersal of gametes or from the migration of individuals.