Answer: In adaptive radiation, many different species evolve from a single ancestor species. Each new species evolves to exploit a different niche, such as food source. In the example above, Hawaiian honeycreepers evolved a range of bill forms in response to available food sources on the Hawaiian archipelago. The honeycreepers dispersed from one founder species, and evolved in response to natural selection based on different food sources in their isolated habitats provided by water. Seed-eating birds evolved thick, short beaks.
No a vampire bat does not go through metamorphosis
Theory of adaptation is valid because scientist can see facts that supported the theory. Adaptation makes organism survive especially in this rapid changing world. For instance, parts of human anatomy like appendix and tail bone were still present in humans but are no longer functional.
The main difference between vascular and nonvascular plants is that a vascular plant has vascular vessels to carry water and food to all the different parts of the plant.