Red crossbills (Loxia curvirostra species complex) are small finches specialized for eating seeds pried out of the cones of conifer trees. They fly thousands of kilometers each year in search of productive cone crops. Despite their mobility, crossbills have diverged into several "types" that differ in bill shape, body size, and vocalizations. Each type prefers to feed on a different species of conifer, and each species of conifer is found only in certain forests. Bill size and shape affect how efficiently a bird can open cones of a certain conifer species. The divergence of different types in the absence of any geographic barrier is an example of:Group of answer choices