Related Experiment Video
Updated: Jul 7, 2026
08:59
The Other End of the Leash: An Experimental Test to Analyze How Owners Interact with Their Pet Dogs
Published on: October 13, 2017
Assortative mating and fragmentation within dog breeds.
Susanne Björnerfeldt1, Frank Hailer, Maria Nord
1Department of Evolutionary Biology, Uppsala University, S-752 36 Uppsala, Sweden. Susanne.Bjornerfeldt@hgen.slu.se
BMC Evolutionary Biology
|January 30, 2008
Summary
Genetic analysis reveals distinct subgroups within poodles, challenging the assumption of uniformity. These findings highlight how selective breeding creates significant genetic fragmentation within dog breeds.
Area of Science:
- Canine genetics
- Population genetics
- Animal breeding
Background:
- Dogs exhibit remarkable diversity across ~400 breeds, shaped by human selection.
- Genetic differences between breeds and linkage disequilibrium within breeds make dogs valuable models for human disease gene mapping.
- This study investigated genetic diversity within poodles, comparing them to eight other breeds.
Purpose of the Study:
- To analyze genetic diversity and population structure within poodles.
- To compare genetic patterns in poodles to other dog breeds.
- To understand the impact of breeding practices on genetic uniformity.
Main Methods:
- Genetic diversity analysis of 164 poodles and 133 dogs from eight other breeds.
- Pedigree analysis tracing three generations.
- Comparison of genetic structure across breeds.
Main Results:
- Strong population structure was identified within poodles, with distinct subgroups.
- Subgroups result from assortative mating driven by breed standards and breeder preferences, not random mating.
- Five novel poodle groups, based on size and color, were identified, unrecognized by kennel clubs.
- Patterns suggest assortative mating and fragmentation are common in many dog breeds.
Conclusions:
- Local mating patterns create significant genetic structure within dog breeds like poodles.
- This genetic fragmentation can enhance or hinder association mapping studies if not accounted for.
- Ongoing selection processes continue to drive further subdivision within established dog breeds.
Related Concept Videos
01:43Incomplete 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.
02:03Law 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.
02:03Law 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.
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,...
01:20Mate Choice
Mate choice—the decision about whom to mate with—is a type of natural selection, since animals must reproduce to pass down their genes. Mate choice is also called intersexual selection because the behavior occurs between the sexes.
01:49Law 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.