Assortative Mating - General Characteristics

General Characteristics

Assortative mating occurs on a variety of normal and abnormal traits and may strengthen the mating bond to increase fertility. The mating strategy may work to increase genetic relatedness, which can facilitate communication and altruism. Conversely, disassortative mating reduces genetic relatedness between family members. Ultimately, the goal of assortative mating is to increase inclusive fitness, meaning the sum fitness of the individual and all of the individual’s offspring. However, mating between individuals who are too genetically similar is considered inbreeding and reduces fitness by putting an individual at a greater risk of harmful recessive traits. Although genetic diversification is generally seen as an adaptive strategy in unpredictable environments, decreasing genetic diversity can provide stability in predictable environments.

Furthermore, assortative mating may be required for sympatric speciation, meaning the evolution of a new species without geographic isolation. Instead, isolated mating via assortative mating may trigger speciation. This has been observed in the Middle East blind mole rat, cicadas, and the European corn borer.