Related Experiment Video
Updated: Nov 18, 2025
04:52
Following the Dynamics of Structural Variants in Experimentally Evolved Populations
Published on: February 3, 2023
1.2K
Genetic and phenotypic variation exhibit both predictable and stochastic patterns across an intertidal fish
Joshua A Thia1,2, Katrina McGuigan1, Libby Liggins3
1School of Biological Sciences, The University of Queensland, Saint Lucia, QLD, Australia.
Molecular Ecology
|February 5, 2021
Summary
Evolutionary processes like selection, gene flow, and drift create complex genetic and phenotypic patterns in the intertidal fish Bathygobius cocosensis. These patterns vary across space, time, and life stages, revealing both predictable and stochastic microevolutionary dynamics.
Area of Science:
- Evolutionary biology
- Population genetics
- Marine ecology
Background:
- Adaptive evolution is shaped by interactions between selection, gene flow, and genetic drift.
- These evolutionary forces can vary across spatial, temporal, and ontogenetic scales, influencing microevolutionary outcomes.
- Understanding these dynamics is crucial for predicting species' responses to environmental changes.
Purpose of the Study:
- To investigate how space, time, and life stage influence genetic and phenotypic variation in the intertidal fish Bathygobius cocosensis.
- To determine the predictability and stochasticity of microevolutionary patterns in a marine species with complex life cycle and dispersal potential.
- To identify targets of selection and their variability across different ecological dimensions.
Main Methods:
- Genome-wide single nucleotide polymorphisms (SNPs) were used to analyze genetic structure.
- Outlier locus analyses identified potential targets of selection.
- Phenotypic data (head shape) were collected and analyzed alongside genetic data.
- Sampling included juvenile and adult life stages across three sites over three years.
Main Results:
- Chaotic genetic patchiness was observed: weak but significant spatial genetic structure that varied over time and between life stages.
- Targets of selection were largely temporally variable, but some spatial outliers were shared between life stages.
- Head shape exhibited high temporal variability within sites, yet spatial patterns suggested predictable environmental influences.
- Marine systems exhibit complex microevolutionary dynamics with both predictable and stochastic patterns.
Conclusions:
- Microevolutionary dynamics in marine species are complex, influenced by multiple ecological dimensions.
- Consideration of space, time, and life stage is essential for understanding genetic and phenotypic variation.
- Findings are relevant to species with complex life cycles, high dispersal, and heterogeneous environments.
Related Concept Videos
01:09Mutation, Gene Flow, and Genetic Drift
60.9K
In a population that is not at Hardy-Weinberg equilibrium, the frequency of alleles changes over time. Therefore, any deviations from the five conditions of Hardy-Weinberg equilibrium can alter the genetic variation of a given population. Conditions that change the genetic variability of a population include mutations, natural selection, non-random mating, gene flow, and genetic drift (small population size).
60.9K
02:39Gene Flow
36.7K
Gene flow is the transfer of genes among populations, resulting from either the dispersal of gametes or from the migration of individuals.
36.7K
03:33Genetic Drift
42.0K
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.
42.0K
01:07Speciation Rates
22.1K
Overview
22.1K
00:57Population Growth
26.6K
Population size is dynamic, increasing with birth rates and immigration, and decreasing with death rates and emigration. In ideal conditions with unlimited resources, populations can increase exponentially, which plots as a J-shaped growth rate curve of population size against time. This type of curve is characteristic of newly-introduced invasive species, or populations that have suffered catastrophic declines and are rebounding.
26.6K
01:25What is Population Genetics?
63.3K
A population is composed of members of the same species that simultaneously live and interact in the same area. When individuals in a population breed, they pass down their genes to their offspring. Many of these genes are polymorphic, meaning that they occur in multiple variants. Such variations of a gene are referred to as alleles. The collective set of all the alleles within a population is known as the gene pool.
63.3K