Therefore, vestigial structures can be considered evidence for evolution, the process by which beneficial heritable traits arise in populations over an extended period of time.

According to evolutionary psychology, traits arise from a process of mutation and selection.

Scientists suspect, however, that the trait arose early in human evolution, probably to allow men to hunt or, when needed, to flee.

These traits arise from the interaction of its genotype with the environment.

The trait arose a number of times in different groups during the Cenozoic, and in each instance was immediately followed by an adaptive radiation.

Analogous traits will often arise due to convergence, where different species live in similar ways and/or similar environment, and thus face the same environmental factors.

How those traits arose is beside the point, argues Dr. Paul W. Sherman, a neurobiologist at Cornell and a leading researcher in the evolution of behavior.

Yet while both South American traditions were influential in western Mexico, idiomatic traits and styles arose in the region, growing out of the imported traditions.

As mammals reach sexual maturity, secondary sexual traits arise.

These traits typically arise due to mutations, which occur more frequently in pathogen populations than in host populations, due to the pathogens' rapid generation time and immense numbers.