Related Experiment Video
Updated: Aug 14, 2026
09:34
Assessing Differences in Sperm Competitive Ability in Drosophila
Published on: August 22, 2013
Competition and the Effect of Spatial Resource Heterogeneity on Evolutionary Diversification
The American Naturalist
|May 11, 2000
Summary
Spatial resource heterogeneity can impact evolutionary diversification. While it can promote disruptive selection, it may also hinder it, especially with low migration rates between habitats.
Area of Science:
- Ecology
- Evolutionary Biology
- Population Genetics
Background:
- Competition for resources drives evolutionary diversification.
- Spatial resource heterogeneity influences ecological and evolutionary dynamics.
- Disruptive selection favors polymorphism and can lead to new resource exploitation strategies.
Purpose of the Study:
- To model how spatial resource heterogeneity affects disruptive selection.
- To determine conditions favoring evolutionary diversification of resource use.
- To compare disruptive selection in identical versus heterogeneous resource patches.
Main Methods:
- A mathematical model simulating a single species in two connected patches.
- Patches differ in resource type and are connected by migration.
- Analysis of conditions leading to disruptive selection and character displacement.
Main Results:
- When patches are identical, disruptive selection matches previous character displacement models.
- Heterogeneous patches can either ease or tighten conditions for disruptive selection based on demographics.
- Spatial heterogeneity can surprisingly reduce evolutionary diversification, like character displacement.
Conclusions:
- Spatial resource heterogeneity's effect on disruptive selection is complex and depends on demographic factors.
- Low migration rates consistently amplify the disruptive effect of spatial heterogeneity.
- Understanding these dynamics is crucial for predicting evolutionary trajectories in varied environments.
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.
01:09Mutation, 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).Mechanisms of Genetic VariationThe original sources of genetic variation are mutations,...
02:02Ecological Niches
All organisms have a position within an ecosystem. The complete set of living and nonliving factors—including food resources, climate, and terrain—that define the position of a given organism are collectively referred to as the organism’s ecological niche.Multiple species cannot occupy the exact same niche within their habitat. If the niches of two or more species overlap to a large extent, the competitive exclusion principle dictates that one species will outcompete the other, forcing it to...
02:34Competition
When organisms require the same limited resources within an environment, they may have to compete for them. Competition is a net-negative interaction. Even if two competing individuals or populations do not interact directly, the overall fitness of both competitors is lowered as a result of not having full access to the limited resource.Intraspecific competition, which occurs between individuals of the same species, serves as a natural mechanism for regulating population size. Too much...
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...
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.