1. Patterns of Evolution

2. Macroevolution
Evolutionary patterns and processes that occur over long periods of time.
Six Topics
Mass Extinction
Adaptive Radiation
Convergent Evolution
Coevolution
Changes in Developmental Genes

3. Mass Extinction
Periods in Earth’s history where entire ecosystems collapsed.
Large groups of organisms went extinct due to density-independent problems.
Example: K-T Extinction
An asteroid hit the earth causing major tectonic activity – earthquakes, volcanoes.
Massive climate change over a short period killed the dinosaurs.

4. Adaptive Radiation
A single species of animal evolves into many different species that lives in different ways.
Mammals today evolved from a group of species that looked like shews.

5. Convergent Evolution
Unrelated organisms in the same environment have body structures that look and act the same.
Examples
Fins on dolphins, penguins and sharks
Wings on birds, bats and insects

6. Coevolution
Two or more species evolve in response to changes in each other over time.
Butterflies and flowers
Cows and plant poisons

7. Developmental Genes
Animals share similar genes that are active early during embryonic development.
Hox genes
Small changes in the Hox genes can lead to large developmental differences.

8. Hox examples