1. Homologous features Analogous features Vestigial structures
15.3 Evidence of Evolution
Homologous features
Analogous features
Vestigial structures

2. Homologous features
· Similar features that have same structures but different functions. They come from the same structures in the embryo.
· Indicates that different species shared a common ancestor.
Ex. P.289 fig Penguin, alligator, human and bat.

3. Analogous Features
· Features which have different structures but similar functions. Shows no common ancestor.
Ex. P wings of hummingbird and wings of humming moth.

4. Vestigial Structures ·Features which serve no function.
  Exs. Tailbone, appendix, nictitating membrane.
· These features use to be useful to an ancestor.
· Whales are probably descended from a land animal. Some whales have vestigial hind legs.

5. Coevolution *Parasites with their hosts. *Predator with prey.
·  The change of 2 or more species in close association with each other.
*Parasites with their hosts.
*Predator with prey.
*Tropical bat with its flower it feeds on p. 291

6. Convergent Evolution vs. Divergent Evolution
A. Convergent evolution
*Shark and porpoise. They look similar but not closely related. Have analogous fins. Have same phenotypes which means they look the same.

7. B. Divergent Evolution
*Dogs. They all are closely related but look different.
1.   Adaptive radiation
*many related species evolve from a single ancestor
2.   Artificial selection
*Breeding for specific phenotypes like in dogs.
*Gives a variety of species
*Speeds up divergent evolution.