Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Dihybrid Crosses

Dihybrid Crosses

Law of Independent Assortment

Law of Independent Assortment

While Mendel’s Law of Segregation states that the two alleles for one gene are separated into different gametes, a different question of how different genes are inherited remains. For example, is the gene for tall plants inherited with the gene for green peas? Mendel asked this question by experimenting with a dihybrid cross; a cross in which both parents are homozygous for two distinct traits resulting in an F1 generation that are heterozygous for both traits.

Law of Segregation

Law of Segregation

When crossing pea plants, Mendel noticed that one of the parental traits would sometimes disappear in the first generation of offspring, called the F1 generation, and could reappear in the next generation (F2). He concluded that one of the traits must be dominant over the other, thereby causing masking of one trait in the F1 generation. When he crossed the F1 plants, he found that 75% of the offspring in the F2 generation had the dominant phenotype, while 25% had the recessive phenotype.

Hardy-Weinberg Principle

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.

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).

Incomplete Dominance

Incomplete Dominance

Gregor Mendel's work (1822 - 1884) was primarily focused on pea plants. Through his initial experiments, he determined that every gene in a diploid cell has two variants called alleles inherited from each parent. He suggested that amongst these two alleles, one allele is dominant in character and the other recessive. The combination of alleles determines the phenotype of a gene in an organism.

You might also read

Related Articles

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

Sort by

Same author

Neutral Genetic Diversity in Mixed Mating Systems.

Genes·2025

Same author

Wright's Hierarchical F-Statistics.

Molecular biology and evolution·2024

Same author

Allele frequency spectra in structured populations: Novel-allele probabilities under the labelled coalescent.

Theoretical population biology·2020

Same author

Inductive determination of allele frequency spectrum probabilities in structured populations.

Theoretical population biology·2019

Same author

Evolution of the sex ratio and effective number under gynodioecy and androdioecy.

Theoretical population biology·2017

Same author

ON THE EVOLUTION OF PARTHENOGENESIS. II. INBREEDING AND THE COST OF MEIOSIS.

Evolution; international journal of organic evolution·2017

Search research articles

Related Experiment Video

Updated: Jun 14, 2025

Combined Immunofluorescence and DNA FISH on 3D-preserved Interphase Nuclei to Study Changes in 3D Nuclear Organization

Combined Immunofluorescence and DNA FISH on 3D-preserved Interphase Nuclei to Study Changes in 3D Nuclear Organization

Published on: February 3, 2013

Joint identity among loci under mutation and regular inbreeding.

Marcy K Uyenoyama¹

¹Department of Biology, Duke University, Box 90338, Durham, NC 27708-0338, USA.

Theoretical Population Biology

|August 29, 2024

Summary

This study presents a new method to calculate joint probabilities of identity-by-state (IBS) across genes. The findings reveal that genetic diversity, not allele frequencies, influences multi-locus associations.

Keywords:

Effective number Linkage disequilibrium Mating system Selfing Two-locus identity

More Related Videos

Genetic Mapping of Thermotolerance Differences Between Species of Saccharomyces Yeast via Genome-Wide Reciprocal Hemizygosity Analysis

Genetic Mapping of Thermotolerance Differences Between Species of Saccharomyces Yeast via Genome-Wide Reciprocal Hemizygosity Analysis

Published on: August 12, 2019

Shifting Zebrafish Lethal Skeletal Mutant Penetrance by Progeny Testing

Shifting Zebrafish Lethal Skeletal Mutant Penetrance by Progeny Testing

Published on: September 1, 2017

Related Experiment Videos

Last Updated: Jun 14, 2025

Combined Immunofluorescence and DNA FISH on 3D-preserved Interphase Nuclei to Study Changes in 3D Nuclear Organization

Combined Immunofluorescence and DNA FISH on 3D-preserved Interphase Nuclei to Study Changes in 3D Nuclear Organization

Published on: February 3, 2013

Genetic Mapping of Thermotolerance Differences Between Species of Saccharomyces Yeast via Genome-Wide Reciprocal Hemizygosity Analysis

Genetic Mapping of Thermotolerance Differences Between Species of Saccharomyces Yeast via Genome-Wide Reciprocal Hemizygosity Analysis

Published on: August 12, 2019

Shifting Zebrafish Lethal Skeletal Mutant Penetrance by Progeny Testing

Shifting Zebrafish Lethal Skeletal Mutant Penetrance by Progeny Testing

Published on: September 1, 2017

Area of Science:

Population genetics
Statistical genetics
Genomics

Background:

Understanding genetic variation patterns is crucial for population genetics.
Classical indices of association often rely on allele frequencies.
Previous methods may not fully capture complex evolutionary forces.

Purpose of the Study:

To develop a compact method for determining joint probabilities of identity-by-state (IBS) within and between loci.
To analyze population evolution under genetic drift, crossing-over, mutation, and inbreeding.
To derive analogues of classical association indices from joint identities.

Main Methods:

Coalescence-based analysis.
Calculation of joint probabilities of identity-by-state (IBS).
Modeling populations under genetic drift, crossing-over, mutation, and partial self-fertilization.

Main Results:

Joint identities provide analogues of classical association indices.
Multi-locus associations are linked to simultaneous coalescence events across loci.
Measures of association depend on genetic diversity, not allele frequencies.

Conclusions:

The developed method offers a compact way to analyze IBS.
Association measures are influenced by genetic diversity, providing insights into population structure.
Scaled indices can aid in interpreting genome-scale variation patterns related to evolutionary rates.