Geoscience Reference
In-Depth Information
Evolutionary Processes
The fauna as well as flora of Tropical Forest Biomes are highly diverse. The length
of time these regions have remained isolated with abundant heat and moisture
have provided ample opportunity for animals to develop unique niches and strat-
egies for survival. Continuous plant diversification through evolution leads to
increasingly diverse habitats and abundant opportunities for the diversification of
animal species. These millions of years of isolation with little floral or faunal
exchange have created opportunities for speciation through adaptive radiation, the
evolution of many species from a single ancestral species. This often happens in
concert with isolation.
Another evolutionary phenomenon displayed in the tropical rainforests of the
world is convergent evolution. Convergent evolution is the development of two or
more species that resemble each other or share similar behaviors but are totally
unrelated. Hummingbirds of
the Neotropics and sunbirds in Africa and the
Figure 1.3 Examples of convergent evolution. Although the animals shown look simi-
lar, they are unrelated.
(Illustration by Jeff Dixon.)
