Selection of advantageous new phenotypes

A phenotype is an observable characteristic of an organism. A new phenotype can be inherited if it is associated with a genetic variant that can be passed from parents to offspring.

If the environment changes, a phenotype may become advantageous because it makes individuals better suited to the new conditions. Individuals with that phenotype may be more likely to survive and reproduce than others in the population. When they reproduce, they can pass the associated genetic variant to their offspring, which may then show the same phenotype.

Over generations, the genetic variant and its associated phenotype can become more common in the population. This process is called natural selection. If the advantageous phenotype spreads through the population over relatively few generations, the species can change relatively rapidly.