Summary
A heritable trait that improves an organism's survival and reproduction in its environment.
In depth
Adaptations can be structural, physiological or behavioural. They evolve by selection over many generations, not within an individual's lifetime. Not every trait is an adaptation; some arise by drift or as by-products.
Adaptation is always relative to an environment and can become maladaptive if conditions change.
Biologists test whether a trait is an adaptation by comparing species, experiments and models of fitness cost and benefit. Gould and Lewontin warned against just-so stories, since some traits are by-products (spandrels), results of drift, or exaptations, features that evolved for one purpose and were later used for another, like feathers (probably first for insulation) used later in flight.
Adaptations are imperfect because of trade-offs, history and constraints: the vertebrate eye has a blind spot because the retina is wired backward, which the octopus eye avoids. Adaptation also lags behind changing environments.
Example: the hollow hairs of polar bears trap warm air, and their dark skin absorbs heat, both adaptations to the Arctic.
Frequently asked questions
What is Adaptation?
A heritable trait that improves an organism's survival and reproduction in its environment.
Which area of biology covers Adaptation, and how advanced is it?
Adaptation is one of the 53 topics in Evolution. It is rated Beginner, so it suits learners who are starting out in biology. Related topics in this area include Convergent Evolution, Evolutionary Trade-offs, Natural Selection.
Can you give an example of Adaptation?
The streamlined body of dolphins reduces drag in water, and camel kidneys conserve water.
What should I learn before Adaptation?
Adaptation is a Beginner topic, so no earlier topic is required. Other Beginner topics in Evolution that pair well with it include Evolution, Natural Selection, Charles Darwin.
What topics are related to Adaptation?
The closest topics to Adaptation are Convergent Evolution, Evolutionary Trade-offs, Natural Selection, Macroevolution. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Adaptation?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Adaptation. To practise the whole of Evolution, use the Evolution quiz.
How is Adaptation different from Convergent Evolution?
Adaptation: A heritable trait that improves an organism's survival and reproduction in its environment. Convergent Evolution: Unrelated lineages evolve similar traits because they face similar selective pressures. Read both side by side and note what each one explains.
How should I study Adaptation step by step?
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 Convergent Evolution and explain the difference aloud. Finally, take the Evolution quiz and come back to this page for any question you miss.