EvolutionLesson 4 of 5 in the course Natural selection

Sexual Selection: Mechanisms, Signals, and Evolutionary Effects

5 flashcards · 5 quiz questions · 5 match pairs · 5 fill-in sentences · English

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Summary

Sexual selection explains how differences in mating success can shape the evolution of traits. It complements the broader process of natural selection and helps explain ornaments, courtship displays, and competition for mates.

These processes do not mean that every individual reproduces equally. Individuals that win contests or are preferred as mates may leave more offspring than others. A trait can therefore spread even if it does not directly improve survival.

All flashcards

Fisherian runaway
Positive feedback in which an inherited mating preference and the preferred trait become associated and increase together.
Sexual dimorphism
A difference between the sexes in traits such as size, ornamentation, or weaponry.
Handicap principle
The idea that a costly display can signal quality because its bearer sustains the cost.
Bateman's principle
The proposal that the sex investing more in offspring becomes a limiting resource for which the other sex competes.
Cryptic female choice
Processes after mating through which a female can influence which sperm succeed.

Quiz questions

  1. In Fisherian runaway, how can a preferred trait and a mating preference increase together?Answer: The trait and preference are inherited and become associated across generations.
  2. What does Bateman's principle propose about reproductive investment?Answer: The sex investing more in offspring may become a limiting resource for which the other sex competes.
  3. What form of parental care is illustrated by male water bugs?Answer: They carry eggs attached to their backs, which can limit feeding and mating opportunities.
  4. What does sex-role reversal describe in sexual selection?Answer: Patterns of competition, display, or mate choice differ from commonly expected sex roles.
  5. How can floral traits contribute to sexual selection in flowering plants?Answer: Features such as symmetry, nectar, or flower structure can affect pollinator visits and reproductive success.

Based on the Wikipedia article Sexual selection, licensed CC BY-SA 4.0. Adapted into a summary, flashcards and quizzes.

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