This lesson introduces the different meanings of adaptation and traces how explanations for it changed from ancient philosophy to evolutionary biology.
In biology, adaptation has three closely related meanings. First, it is the evolutionary process through which natural selection makes populations better suited to their environments. Second, it is the state of being adapted, or how well a population fits its surroundings. Third, an adaptive trait is a feature or function in an organism that has been maintained and shaped by natural selection because it contributes to survival or reproduction.
All flashcards
Adaptation as an evolutionary process
Population change across generations as natural selection makes heritable traits more common when they improve reproductive success.
Acclimatization
An individual's automatic physiological adjustment to environmental conditions during its lifetime.
Adaptedness
How well a phenotype fits its local ecological niche.
Evolutionary fitness
A genotype's contribution to later generations, measured relative to others or in absolute terms.
Exaptation
A shift in the function of an existing feature that is co-opted for a different use.
Quiz questions
What mechanism did Charles Darwin and Alfred Russel Wallace propose to explain adaptation?Answer: Natural selection acting on heritable variation across generations.
When a habitat becomes unsuitable, which population response is evolutionary adaptation?Answer: Heritable characteristics change in the population over generations.
Which situation illustrates Batesian mimicry?Answer: A harmless species resembles a defended species that predators avoid.
What is niche construction?Answer: Organisms modify surroundings in ways that affect survival, reproduction, and selection.
What is coextinction?Answer: The loss of one species causes the loss of a species dependent on it.
Based on the Wikipedia article Adaptation, licensed CC BY-SA 4.0. Adapted into a summary, flashcards and quizzes.