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Mutation, Gene Flow, and Genetic Drift

Mutation, Gene Flow, and Genetic Drift

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).

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Updated: Jul 19, 2025

Following the Dynamics of Structural Variants in Experimentally Evolved Populations

Following the Dynamics of Structural Variants in Experimentally Evolved Populations

Published on: February 3, 2023

Digest: Multivariate genetic variation constrains adaptation to environmental changes during range expansion.

Haoran Cai¹, David Des Marais¹

¹Department of Civil and Environmental Engineering, MIT, Cambridge, MA, United States.

Evolution; International Journal of Organic Evolution

|August 8, 2023

Summary

This summary is machine-generated.

Population divergence at range edges may be constrained by limited genetic variation and evolvability, hindering species expansion. This study examined selection and genetic variation in ivy-leaved morning glory to understand these constraints.

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Area of Science:

Evolutionary biology
Population genetics
Ecology

Background:

Understanding how populations diverge and adapt across landscapes is crucial for predicting species' responses to environmental change.
Selection and standing genetic variation are key factors influencing evolutionary trajectories and population divergence.

Purpose of the Study:

To investigate the relationship between selection gradients, genetic covariance (G-matrix), and population divergence in the ivy-leaved morning glory (Ipomoea hederacea).
To assess potential genetic constraints on population divergence and range expansion at the species' range edge.

Main Methods:

Field-based estimation of selection gradients on plant traits.
Comparison of selection gradients with the G-matrix and measures of population divergence.
Analysis of four North American populations of Ipomoea hederacea.

Main Results:

Population divergence and genetic covariances were largely unaligned with the estimated selection gradient at the species' range edge.
This misalignment suggests potential limitations in the evolutionary response of populations at range edges.

Conclusions:

Limited evolvability or multivariate genetic variation may restrict species' range expansion.
Genetic constraints play a significant role in population divergence and local adaptation, particularly under changing climate conditions.