Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Mutation, Gene Flow, and Genetic Drift01:09

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).
Conservation of Small Populations02:04

Conservation of Small Populations

Small population sizes put a species at extreme risk of extinction due to a lack of variation, and a consequent decrease in adaptability. This weakens the chances of survival under pressures such as climate change, competition from other species, or new diseases. Large populations are more likely to survive pressures such as these, as such populations are more likely to harbor individuals that have genetic variants that are adaptive under new stresses. Small populations are much less likely to...
Genetic Drift03:33

Genetic 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.
Hardy-Weinberg Principle01:49

Hardy-Weinberg Principle

Diploid organisms have two alleles of each gene, one from each parent, in their somatic cells. Therefore, each individual contributes two alleles to the gene pool of the population. The gene pool of a population is the sum of every allele of all genes within that population and has some degree of variation. Genetic variation is typically expressed as a relative frequency, which is the percentage of the total population that has a given allele, genotype or phenotype.
Gene Flow02:39

Gene Flow

Gene flow is the transfer of genes among populations, resulting from either the dispersal of gametes or from the migration of individuals.
What is Population Genetics?01:25

What is Population Genetics?

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.

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Genomic Data Reveal Multiple Introduction Sources and Limited Post-Colonization Gene Flow in Southeast Michigan Invasive Red Swamp Crayfish (<i>Procambarus clarkii</i>).

Ecology and evolution·2025
Same author

Development of PCR Blocking Primers Enabling DNA Metabarcoding Analysis of Dietary Composition in Hematophagous Sea Lamprey.

Ecology and evolution·2025
Same author

Genomic Data Characterize Reproductive Ecology Patterns in Michigan Invasive Red Swamp Crayfish (<i>Procambarus clarkii</i>).

Evolutionary applications·2024
Same author

Evaluating the utility of effective breeding size estimates for monitoring sea lamprey spawning abundance.

Ecology and evolution·2023
Same author

Primary anterior cruciate ligament repair: Current concepts.

Journal of ISAKOS : joint disorders & orthopaedic sports medicine·2023
Same author

Host gene expression is associated with viral shedding magnitude in blue-winged teals (Spatula discors) infected with low-path avian influenza virus.

Comparative immunology, microbiology and infectious diseases·2022

Related Experiment Video

Updated: May 10, 2026

Following the Dynamics of Structural Variants in Experimentally Evolved Populations
04:52

Following the Dynamics of Structural Variants in Experimentally Evolved Populations

Published on: February 3, 2023

Linkage disequilibrium and effective population size when generations overlap.

John D Robinson1, Gregory R Moyer

  • 1Conservation Genetics Lab, Fish Technology Center, U.S, Fish and Wildlife Service Warm Springs, GA, USA.

Evolutionary Applications
|June 27, 2013
PubMed
Summary

Estimating effective population size is crucial for conservation. Overlapping generations can bias estimates, but sampling adults with the linkage disequilibrium method provides reliable results for population size.

Keywords:
LDNeNbNeSPIPage structurecomputer simulationseffective number of breedersmicrosatellites

More Related Videos

Predicting the Effectiveness of Population Replacement Strategy Using Mathematical Modeling
20:36

Predicting the Effectiveness of Population Replacement Strategy Using Mathematical Modeling

Published on: July 4, 2007

Daily Transfers, Archiving Populations, and Measuring Fitness in the Long-Term Evolution Experiment with Escherichia coli
15:00

Daily Transfers, Archiving Populations, and Measuring Fitness in the Long-Term Evolution Experiment with Escherichia coli

Published on: August 18, 2023

Related Experiment Videos

Last Updated: May 10, 2026

Following the Dynamics of Structural Variants in Experimentally Evolved Populations
04:52

Following the Dynamics of Structural Variants in Experimentally Evolved Populations

Published on: February 3, 2023

Predicting the Effectiveness of Population Replacement Strategy Using Mathematical Modeling
20:36

Predicting the Effectiveness of Population Replacement Strategy Using Mathematical Modeling

Published on: July 4, 2007

Daily Transfers, Archiving Populations, and Measuring Fitness in the Long-Term Evolution Experiment with Escherichia coli
15:00

Daily Transfers, Archiving Populations, and Measuring Fitness in the Long-Term Evolution Experiment with Escherichia coli

Published on: August 18, 2023

Area of Science:

  • Population genetics
  • Conservation biology
  • Evolutionary biology

Background:

  • Estimates of effective population size (Ne) are vital for managing and conserving species.
  • Genetic data and linkage disequilibrium (LD) methods are commonly used to estimate Ne.
  • Current LD methods often assume discrete generations, which may not reflect reality in many species.

Purpose of the Study:

  • To investigate the impact of overlapping generations on effective population size estimates using the LD method.
  • To evaluate how reproductive skew and generation time influence Ne estimates.
  • To determine optimal sampling strategies for accurate Ne estimation in the presence of overlapping generations.

Main Methods:

  • Utilized simulated genetic data to model populations with varying degrees of reproductive skew and generation time.
  • Applied the linkage disequilibrium (LD) method to estimate effective population size from simulated datasets.
  • Compared Ne estimates derived from samples of newborns versus reproductively mature adults.

Main Results:

  • Overlapping generations can introduce bias in effective population size estimates, particularly when reproductive skew is high.
  • Estimates of the effective number of breeders are best obtained from samples of newborns.
  • Estimates of the per-generation effective population size are more accurately derived from random samples of reproductively mature adults, with a downward bias of less than 15% in simulations.
  • Estimate precision is inversely related to the effective population size, with smaller populations yielding more precise estimates.

Conclusions:

  • The choice of sampling strategy (newborns vs. adults) is critical for accurately estimating different measures of effective population size when generations overlap.
  • The LD method, when applied to samples of adults, provides a robust and minimally biased estimate of per-generation effective population size.
  • Understanding the life history, specifically generation time and reproductive skew, is essential for interpreting effective population size estimates in conservation genetics.