What is the concept of 'evolutionary rescue' in coral adaptation?

The concept of 'evolutionary rescue' refers to the potential for species, including corals, to undergo rapid evolutionary changes that enhance their resilience to environmental stressors. This phenomenon is particularly crucial in the context of climate change and other anthropogenic pressures that threaten coral reefs.

When corals experience stressed conditions such as rising sea temperatures, ocean acidification, and nutrient loading, there is an opportunity for natural selection to favor certain genotypes that demonstrate tolerance or resilience to these stressors. Over successive generations, alleles associated with beneficial traits can increase in frequency within a population, providing a mechanism for coral species to withstand adverse environmental changes effectively.

This rapid evolutionary response can be vital for the survival of coral populations, especially in environments changing at an unprecedented rate. The other options do not accurately capture this principle; for instance, gradual adaptation focuses on long-term changes rather than rapid evolutionary shifts, while the elimination of non-native coral species and asexual reproduction relate to different ecological and biological processes, not the evolutionary adjustments in response to stress.