1. Evolution

2. Evolution Evolution = change in a population over time
Is there any evidence of this phenomenon?

3. Evidence for Evolution
Fossils
Trace of long-dead organism (ex. Mold, imprint, amber)
Can tell us what kind of organisms existed at various times in Earth’s history
Where they lived, their behavior, and their extinctions
Record is incomplete (”missing links”)

4. How to date a fossil
Relative dating – can tell if a fossil is older or younger than another fossil
Older fossils are deeper in sediment
Absolute dating – uses radioactive decay to estimate the age of the fossil in years
Using the half-life of C-14

5. Evidence for Evolution
Adaptations
Anything that allows an organism to survive better in its environment
Natural selection
Ex. Thorns, claws, mimicry, camouflage, etc.

6. Mimicry
Mimicry = non-harmful species resembling a harmful species/predator
Ex. Scarlet king snake and coral snake
Monarch butterfly and the viceroy butterfly

7. Camouflage
Camouflage = species blending in with environment

8. Evidence for Evolution
Anatomical Structure
Homologous Structures = similar bone structure (anatomy) but different limb and different function
Analogous Structures = different bone structure (anatomy) but same function

9. Vestigial Structures
Vestigial structures = organisms with structures that have no present day use that suggests their ancestors might have used them 

10. Evidence for Evolution
Biochemical Similarities
Comparison of DNA/RNA/Proteins from different organisms shows how closely they are related
Can be used for cladograms

11. Why does evolution matter now?
Impact in the food we eat, our environment, and our health
2 applications of evolution:
Antibiotic-resistant bacteria
Pesticide-resistant insects

12. Antibiotic Resistant Bacteria
Bacteria reproduce and mutate at a very high rate
Some bacteria’s DNA has mutated to be resistant to many known antibodies

13. Antibiotic Resistant Bacteria
When the resistant bacteria reproduce, they pass this ability onto their offspring
Bacteria can also pass the resistance to other bacteria through conjugation (bacterial sexual reproduction)

14. Pesticide Resistant Insects
Same mechanism as the antibiotic resistant bacteria
To help prevent this:
Don’t overuse pesticides
Raise/buy organic food
Use bio-controls (such as lady bugs)