1. Patterns of Evolution: Convergent Evolution & Divergent Evolution1

2. Convergent Evolution
Occurs when different organisms that live in similar environments become more alike in appearance and behavior
The environment selects similar adaptations in unrelated species.
Organisms develop analogous structures (same function, but different origins).
Examples: - Bird wings/insect wings
- Shark fins/dolphin fins 2

3. More examples: Placental Mammals: top row
Marsupial Mammals: bottom row 3

4. Convergent Evolution
Dolphins and Sharks

5. Coevolution When two species evolve together.
There is a mutual evolutionary influence between two species.
The species have a symbiotic relationship (interaction between members of two populations).
Example: - Birds and flowers 5

6. Divergent Evolution
The process by which an ancestral species gives rise to a number of new species that are adapted to different environmental conditions and are less alike.
Often occurs when a species colonizes a new environment.
Examples: - Darwin’s Finches
- Brown bears and polar bears 6

7. Divergent Evolution 7

8. 8