Ecology 6th Edition by Manuel Molles

Exercise 4

There is genetic evidence that mating between G. magnirostris and G. fortis (see fig. 13.8, p. 287) may have helped establish sufficient genetic variation in the population of G. fortis at El Garrapatero for the distribution of beak sizes at that site (see fig. 4.13 ) to emerge under the influence of disruptive selection. Explain.