Evolutionary Perspective on Emotions

An evolutionary approach defines what emotions are in terms of how they came to exist. Emotions are modes of functioning, shaped by natural selection, that coordinate physiological, cognitive, motivational, behavioural and subjective responses in patterns that increase the ability to meet adaptive challenges of situations that have recurred over evolutionary time.

Reference:
Nesse, R. M., & Ellsworth, P. C. (2009). Evolution, emotions, and emotional disorders. American Psychologist, 64(2), 129-139. doi: 10.1037/a0013503