Crossbills are birds whose mandible cross rather than meet. the bill is thought to be an adaptation to extracting seeds from the cones of pine and spruce trees. each type of cone favors a different shape of mandible. a single population of crossbills occurs where there are three species of pines. if the population were to undergo a speciation event, it would most likely be: a) vicariance speciation through local adaptationb) founder event speciation through chance colonizationc) ecological speciation through disruptive selectiond) sexual selection-driven speciation through assortative matinge) all of the above are possible