1. Change Throughout Time
Which Came First?
Change Throughout Time

2. Scientists (500B.C.E.-1859C.E.) Geologic evidence: Earth is old
Fossil evidence: Life is old & 99% species are extinct
Fossil evidence: Life today resembles life of the past
Conclusion: Life on Earth has changed over time
HOW?

3. Charles Darwin
Mechanism: Natural Selection

4. Environment changes species
Natural Selection
Organisms better suited to the environment are more likely to survive & reproduce than organisms less suited to the environment.

5. Unity of Life on Earth All life shares a universal common ancestor
Natural selection is the mechanism to describe unity

6. Humans change species Artificial Selection:
humans modify species over generations by selecting & breeding individuals with desired traits

7. Mustard  Many Vegetables

8. Wolves  Many Dog Breeds

9. Populations Evolve Individuals are born with variable DNA from parents
Environment pressures the fitness of individual
Fit individuals pass on successful DNA to offspring
Over time, mutations build within a population
Evolution is a result of changes at the population level

10. Semantics trickery answer
Amniotic egg: ~300,000,000 years ago
Chickens: ~6,000 years ago

11. Most Appropriate Answer
At no point in history can you specifically point to the first chicken or egg, evolutionary change was at the population level not the individual level of life!