1. Evidence for macroevolution
Strongest = Fossil Record
order of fossils in sediments
oldest at bottom
date with radioisotopes

2. Fossil Record
Find successive change in groups of organisms: "missing links"
whale legs & shape

3. Fossil Record
Find successive change in groups of organisms: "missing links"
whales
horse size

4. Fossil Record
Find successive changes: "missing links"
whale legs & shape
horse size
hominid cranium

5. Evidence for macroevolution
DNA: many genes are so similar that they must have diverged from a common ancestor:
Align genes, count diffs

6. Evidence for macroevolution
DNA: many genes are so similar that they must have diverged from a common ancestor
Align genes, count diffs
# changes says when 2 spp. split

7. Molecular clocks
Align genes, count diffs
# changes tells when 2 spp. split
Calibrate with fossil record

8. Mitochondrial DNA traces Mom
only comes from mom & doesn’t recombine
says we split ~ 170,000 years ago
Y chromosome
traces Dad
only comes from
dad & doesn’t
recombine
Says we entered
Europe ~ 50,000
years ago

9. Evidence for macroevolution
Fossil record
DNA
Comparative anatomy: same bones derived from common ancestor:
shape & function
has changed

10. Evidence for macroevolution
Fossil record
DNA
Comparative anatomy: same bones derived from common ancestor: shape & function changed
Vestigial structures: non-functional left-overs

11. Evidence for macroevolution
Fossils
DNA
Comparative anatomy
Embryos retrace evolution as they develop

12. Embryos retrace phylogeny
Embryos retrace evolution as they develop

13. Embryos retrace phylogeny
evolution as they
develop
Close spp look
alike longer

14. Convergent evolution
similar selection results in organisms that look alike
e.g. desert plants: American cacti & African euphorbs look alike but unrelated

15. Convergent evolution
similar selection -> organisms look alike
e.g. Australian
marsupials resemble
American placental
mammals

16. Convergent evolution
similar selection -> organisms look alike
e.g. Australian
marsupials resemble
American placental
Mammals
Fill same niche:
role in nature

17. Analogy vs homology
Analogous: look alike but different origin
Bird vs insect wings

18. Analogy vs homology
Analogous: look alike but different origin
Bird vs insect wings
fins vs flippers

19. Analogy vs homology
Analogous: look alike but diff origin
Bird vs insect wings
fins vs flippers
Homologous: look different, same origin

20. Pace of evolution
Some plants evolve rapidly
Mammals evolve slowly
Starfish evolve very slowly

21. Pace of evolution
Gradualism: gradual evolution
Large populations
Slow change in selection

22. Pace of evolution
Gradualism: gradual evolution
Large populations
Slow change in selection
Punctuated equilibria: evolve in spurts

23. Pace of evolution
Punctuated equilibria: evolve in spurts
small populations
Genetic drift
alters gene
pool
Rapidly adapt
then reach
equilibrium

24. Pace of evolution
Mass extinctions:
O2 poisoning 2 b.y.a. killed most bacteria

25. Mass extinctions
O2 poisoning 2 b.y.a. killed most bacteria
96% of species died at end of Permian
Asteroid 65 m.y.a. killed dinosaurs

26. Mass extinctions
O2 poisoning 2 b.y.a. killed most bacteria
96% of species died at end of Permian: asteroid?
Asteroid 65 m.y.a. killed dinosaurs
Man is causing another mass extinction!
Enable evolution of new spp!

27. Mass extinctions
Enable evolution of new spp!
Formerly occupied niches become available
major factor in success of mammals