There are two forms of Selection involved in Evolution. Both were described by Darwin.1 One is Natural Selection, which is the cumulative effect of the environment on organisms, and the other is Sexual Selection, which is how individual organisms choose their partners. Key to Sexual Selection is attraction: we select partners we find attractive. In humans, this is important, because we have overcome most of the environmental factors that impinge upon us.
While the effects of Sexual Selection are best known in domestic animals, where humans do the selecting, we have shaped ourselves through it, by choosing our sexual partners and at the same time, by making ourselves appealing to our targets.2