Suppose the species in the previous question are birds that differ in diet: species 1 and 3 are insectivorous (they eat insects), and species 2 and 4 are frugivorous (they eat fruit). We also happen to know that another frugivorous species, species 5, is a mainland relative of species 4. Given your best estimate of the phylogenetic history, what has been the probable history of the evolution of diet in this clade of birds