What is adaptive radiation?
Answers
adaptive radiation is a process in which organisms diversify rapidly from an ancestral species into a multitude of new forms, particularly when a change in the environment makes new resources available, creates new challenges, or opens new environmental niches.
Adaptive radiation is a rapid increase in the number of species with a common ancestor, characterized by great ecological and morphological diversity. The driving force behind it is the adaptation of organisms to new ecological contexts. For Simpson [SIM 44], adaptive radiation may not necessarily apply at the scale of the species, but may just as well apply at a higher taxonomic level (major groups of organisms may also appear by adaptive radiation). The diversity of Galapagos finches, discussed above, results from adaptive radiation. It can even be said that theirs is the most typical, most famous case of adaptive radiation studied by scientists. During the course of evolution, their beaks have changed in size and morphology so that they are now adapted to different diets: some species eat mostly animals (e.g. insects), others seeds or plants; some feed in the trees, and others on the ground. Ultimately, it is the variety of environments and food resources that led to the rapid differentiation of these species of finches. All these species share a common ancestor and are now characterized by broad ecological (their diets are different) and morphological (the size and shape of their beaks are different) diversity.