2. The Fossil Record
Fossils are preserved traces of and remains of ancient life.
Fossils form in a variety of ways.
Through fossils we are able show how different groups of organisms changed over time.

3. The Age of Things.
Relative dating: a technique that allows scientists to estimate a fossils compared to other fossils.

4. The Age of Things.
Radiometric Dating: a technique that allows scientists to mathematically determine the exact age of a biological sample.

5. Patterns of Evolution
There are several distinct patterns to how things evolve.

6. Macroevolution: the large scale change over time that takes place over long periods of time.
Important patterns in macroevolution include:
Extinction
Adaptive Radiation
Convergent evolution
Divergent evolution
Coevolution
Punctuated equilibrium
Gradualism
Changes in developmental genes

7. Extinction This is the disappearance, or dying out of a species.
Most extinction occurs when species cannot compete for resources or adapt to changing environments.

8. Adaptive Radiation
The process in which one species evolves into diverse species that live in different ways.
Darwin’s finches are an example.

9. Convergent Evolution
A process in which unrelated species come to look alike because they have evolved similar adaptations to similar environments.

10. Divergent Evolution
The accumulation of differences between groups, leading to the formation of new species.

11. Coevolution
The process by which two species evolve in response to changes in each other.

12. Punctuated Equilibrium
A pattern of evolutionary change. In this pattern, long periods of little or no change are interrupted by short periods of rapid change.

13. Gradualism
A hypothesis, assuming that change comes about gradually or that variation is slow in nature.
This was the pattern believed by Darwin.

14. Changes in developmental genes
May explain some large scale evolutionary change.
For example, some scientists believe that small changes in the development of an embryo can have a large affect on the adult organism.

15. The End.