1. DO NOW In box on note sheet Why is variation important?
Which does NOT cause evolution?
In order for mutations to be heritable, where must they occur?

2. Extinction Phylogenetic Trees
Evolution
Extinction
Phylogenetic Trees

3. Evolution Evolution is the slow change of species over time
Factors that cause evolution, or change to happen:
Competition for finite resources
Sexual reproduction
Genetic Recombination- Meiosis and Fertilization
Mutation
Natural selection
Environment
Variation / Diversity

4. The idea of evolution is that all modern day species evolved from a common ancestor
The first life form was most likely a simple, single-celled organism
Over billions of years, life slowly become multicellular and more complex

5. Scientists estimate that the world is 3.5 billion
years old
Many organisms that lived long ago are no longer present today
Extinction occurs when the adaptations of a species are no longer fit for the environment

7. The fossil record indicates that many organisms have gone extinct.
Extinction is common. Most of the species that lived in the past are no longer present today.

8. All organisms on earth are related and share common ancestors.
The majority of evidence for evolution is from the fossil record.
Scientists try to piece together the history of species by looking at fossils.

9. Present-day organisms evolved from and branched away from other species.
Present-day organisms descended from other species.
Scientists represent the evolution of species with branching trees.

10. Species present in modern times are adapted to today’s environments.
Species not seen in the present are extinct.

13. Modern scientists determine the relatedness of species by comparing molecular and structural evidence
Molecular evidence- DNA analysis

14. Gel electrophoresis- Scientists use an enzyme to cut DNA into fragments. Fragments are separated by size.

18. Structural evidence- physical traits and characteristics (body parts, bones, colors, etc.)

20. Regents Practice