7.
Dogs are genetically very close to wolves. Yet all wolves look similar while the breeds of
dogs look very different from one another. This is best explained by which of the
following:
a. Wolves have very little genetic variation as a species
b. Wolves are selected for camouflage
c. Different dog breeds have been created by artificial selection and inbreeding
d. Dogs evolved more recently than wolves
Dogs vs Wolves: Artificial Selection Explains Dog Breed Diversity
Dogs share close genetic ties with wolves yet display vast breed differences due to human-driven artificial selection and inbreeding.
Correct Answer
Option c. Different dog breeds have been created by artificial selection and inbreeding best explains the phenomenon. Dogs (Canis lupus familiaris) diverged from gray wolves (Canis lupus) around 20,000–40,000 years ago, retaining 98.8–99% genetic similarity. Wolves maintain uniform wild phenotypes under natural selection for survival traits, while humans selectively bred dogs for specific roles like herding, hunting, or companionship, amplifying minor genetic variations into extreme diversity (e.g., Chihuahuas vs. Great Danes). Inbreeding within breeds fixed these traits, reducing genetic diversity compared to wolves (~2.3 million SNP differences among wolves vs. ~1 million within breeds).
Option Analysis
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a. Wolves have very little genetic variation as a species: Incorrect. Wolves exhibit high genetic diversity (~2.3 million SNPs between individuals), higher than village dogs or breeds, though some populations show bottlenecks. Uniform wolf appearance results from stabilizing natural selection, not low variation.
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b. Wolves are selected for camouflage: Incorrect. While coat colors aid camouflage in some wolves (e.g., Arctic white), this does not explain overall similarity; black wolves persist despite poorer camouflage due to immune benefits. Natural selection favors functional uniformity, unlike dogs’ exaggerated traits.
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c. Different dog breeds have been created by artificial selection and inbreeding: Correct, as detailed above. Most breeds emerged in the 1800s via intense human selection, far outpacing natural evolution.
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d. Dogs evolved more recently than wolves: Incorrect. Wolves predate dogs; domestication occurred ~15,000–40,000 years ago from ancient wolf lineages.
This CSIR NET-style question highlights artificial selection in evolution, contrasting natural vs. human-driven processes key to genetics and biotechnology syllabi.
