1. Unit 3 – Biological Evolution
Biology I - Evolution
Unit 3 – Biological Evolution

2. Evidence for Evolution – Age of Earth
James Hutton
1788 Calculated Earth’s age to be millions of years old
Charles Lyell
1830 Rediscovered and reinforced Hutton’s ideas; provided more geological evidence
Radiometric Dating of Age of Earth
Several different sources (Pb from U, Ar from K-40, mass and luminosity of our sun)
Earth 4.54 billion years old ±0.05 billion years

3. Evidence for Evolution – Age of Earth
If Earth is old, then there’s “plenty of time for evolution by natural selection to take place,” (p.466)
If Earth changes, then why can’t the organisms on it change?

4. Evidence for Evolution - Fossils
Robert Hooke
1665 Proved that fossils are organisms’ remains
Revealed variation in the fossil record
Georges Cuvier
1796 Extensively studied fossils
Thomas Malthus
1798 Founder of demography
Theorized that population size was limited by food supply

5. Darwin Born 1809 1831 HMS Beagle’s 5yr. Voyage
1859 Published On the Origin of Species
Died 1882

6. Darwin’s Voyage

7. Darwin’s Observations – Species Vary Globally
Rheas:
Ground-dwelling birds that only live in South America
Ostriches:
Ground-dwelling birds that only live in Africa
Emus:
Australian ground- dwelling flightless bird
Rabbits:
Live in Europe but NOT in South America nor Australia
Kangaroos:
Live in Australia but NOT Europe

8. Darwin’s Observations – Species Vary Locally
Different, yet related, animal species can occupy different habitats within an area
Darwin’s finches (next slide)
Island Tortoises (p.452)

9. Darwin’s Finches

10. Darwin’s Observations – Species Vary Over Time
Picture comes from NASA Science News article
Mosses and ferns 425mya
Flowering plants move from 130mya to between 245 and 290mya, according to Stanford geochemists

11. Evolution Summary Earth is approx. 4.5 billion years old
The Earth itself has changed over time
Fossils indicate some (actually most) species are extinct
Darwin, a naturalist, goes on voyage 1831, observes:
Species vary globally
Species vary locally
Species vary over time

12. Evidence for Evolution – Anatomy and Development
Homologous Structures – body parts that share a common structure

13. Evidence for Evolution – Anatomy and Development
Analogous Structures – body parts that share common function but NOT structure

14. Evidence for Evolution – Anatomy and Development
Vestigial Structures – body parts that have lost much or all of their original function
Examples:
Appendix
Wisdom teeth
Coccyx

15. Evidence for Evolution – Anatomy and Development

16. Evidence for Evolution – Anatomy and Development

17. Evidence for Evolution Summary
Anatomy and Development
Homologous structures
Analogous structures
Vestigial structures
Embryological similarities between different species

18. Evolution by Natural Selection
Variation exists within populations
Some within a population are better suited for survival
Over time, those that are better suited for survival spread their genetic information
Fossil evidence (next slide)

19. Whale Evolution

20. Cladogram – to show similarities

21. Cladogram

22. And one more cladogram