Over a span of several thousand years, a number of species show adaptations to climate change: Drier, warmer conditions select for succulent vegetation and deep taproots in plants, burrowing in mammals and amphibians, and other similar adaptive changes. What could be predicted to happen if the climate shifts in the opposite direction and becomes progressively wetter and cooler?
A) Ongoing processes of adaptation will continue because evolution is goal directed.
B) Different adaptive trends will probably be favored in the new climatic environment.
C) Current adaptive trends will continue, but organisms will now also have to add on adaptations to deal with cool, wet conditions.
D) Adaptation will cease because cool, wet conditions are suitable for all life on Earth.

Question

Quizplus · Accepted Answer

Different adaptive trends will probably be favored in the new climatic environment. As the climate shifts to become wetter and cooler, different adaptations may be favored, such as water-resistant fur or feathers, hibernation or migration, and adaptations for dealing with lower light levels. Organisms may need to develop new strategies to deal with herbivory or other changes in the food web, and some species may not be able to adapt quickly enough to survive in the new environment. Evolution is not goal-directed and can only work with the variation that already exists in a population, so new adaptations will emerge through natural selection if they confer an advantage in the new conditions.

Over a Span of Several Thousand Years, a Number of Species