Consistent differences in size or appearance between the sexes, shaped by sexual selection.
Differences in size, colour and ornaments between sexes. Often male-biased through sexual selection, but in raptors and spiders females are larger. Extreme in elephant seals where males are 3 to 10 times heavier.
Dimorphism includes size, colour and weapons. It relates to mating systems. It may disappear when selection changes.
Example: male lions have manes.
Consistent differences in size or appearance between the sexes, shaped by sexual selection.
Sexual Dimorphism is one of the 53 topics in Zoology & Animal Diversity. It is rated Advanced, so it suits learners who want specialist depth. Related topics in this area include Animal Camouflage and Mimicry, Metabolic Scaling, Island Gigantism and Dwarfism.
Peacock trains versus peahens' camouflage.
Work through the Beginner topics in Zoology & Animal Diversity first, such as Animal Kingdom, Vertebrates and Invertebrates, Sponges, then return to Sexual Dimorphism. Advanced topics assume the Intermediate vocabulary.
The closest topics to Sexual Dimorphism are Animal Camouflage and Mimicry, Metabolic Scaling, Island Gigantism and Dwarfism, Parental Care Evolution. Comparing them side by side is a good way to see how the ideas connect.
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Sexual Dimorphism. To practise the whole of Zoology & Animal Diversity, use the Zoology & Animal Diversity quiz.
Sexual Dimorphism: Consistent differences in size or appearance between the sexes, shaped by sexual selection. Animal Camouflage and Mimicry: Colour and form evolve to hide or imitate other species, as in Batesian and Mullerian mimicry. Read both side by side and note what each one explains.
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Animal Camouflage and Mimicry and explain the difference aloud. Finally, take the Zoology & Animal Diversity quiz and come back to this page for any question you miss.
Colour and form evolve to hide or imitate other species, as in Batesian and Mullerian mimicry.
🦁 Zoology & Animal DiversityMetabolic rate scales with body mass to the three-quarter power, described by Kleiber's law.
🦁 Zoology & Animal DiversityIsolated animals tend to evolve larger or smaller sizes depending on resources and predators.
🦁 Zoology & Animal DiversityCare by one or both parents evolves when benefits to offspring outweigh costs to parents.
🦁 Zoology & Animal Diversity