Along the evolution changes occur in all groups of organisms. These changes do not always remain, but sometimes they increase survival of the group and therefore are transmitted from one generation to another. That is the way by which new species arise, adapted in some extent to their environment. When these changes allow the species to interact successfully with their environment, either by using the same habitat or resource in different ways or by adapting to use different habitats or resources, an adaptive diversification occurs.
In bats, the second most diverse group of mammals, there has taken place an impressive adaptive diversification in the family Phyllostomidae, which is restricted to the New World. This diversification has been linked to changes that occurred in diet and to the morphological and physiological modifications associated with this. The following video illustrates the changes that have had occur in the shape of skull in different lineages of the family, related to the transition to different types of diet from an insectivorous ancestor.
The tree has been pruned from a molecular phylogeny of the family Phyllostomidae that includes 57 taxa. The nodes represent the most recent common ancestor of the species. Therefore, the values corresponding to these nodes are older than the origin of the group to which each species belongs. The latter values are shown in the text.
This video was created for free use as teaching material. As far as possible, Divulgare group, webs.uvigo.es/plantecology/divulgacion.en.html, will continue adding more similar videos.