Question

In Batesian mimicry, a harmless species mimics the distinctive color pattern of a toxic or dangerous one. In Müllerian mimicry, different dangerous species share similar color patterns, in effect mimicking each other. Explain why Batesian mimicry leads to negative frequency dependent selection, whereas Müllerian mimicry leads to positive frequency dependent selection.

Answer 1

Ans :

In Batesian mimicry, it is possible for natural selection to maintain a polymorphism. When a genotype is rare, it is relatively favored by selection and it will increase in frequency. As it becomes more common, its fitness decreases and there may come to a point at which it is no longer favored. That's why Batesian mimicry is negatively frequency dependent.

In Mullerian mimicry, as different species share a common color, predators can remember a common color pattern. If a new mutants or migrants that have color patterns other than the common type are eliminated from the population by predators. Thus the species sharing a common color have the fitness increased .Therefore, Mullerian mimicry is positively frequency dependent.