What is Evolutution?

1. What is Evolutution? • The process by which different kinds of living organisms are thought to have developed and diversified from earlier forms during the... • The gradual development of something, esp. from a simple to a more complex form.

2. Evidence supporting evolution • Fossil record • shows change over time • Anatomical record • comparing body structures • homology & vestigial structures • embryology & development • Molecular record • comparing protein & DNA sequences • Artificial selection • human caused evolution

3. 1. Fossil record • Layers of rock contain fossils • new layers cover older ones • creates a record over time • fossils show a series of organisms have lived on Earth • over a long period of time

4. ? ? ? Complete seriesof transitionalfossils ? We found the fossil — no joke! Land Mammal Where are theintermediate fossils? Someone’s idea of a joke! Ocean Mammal But the joke’s on them!!

5. Morphology/Anatomical Record

6. Homologous • Structures • homo- = same • -logous = information

7. modifies homologous structures Adaptive Radiation - Modifies homologous structures

8. Convergent evolution leads to………. • Analogous Structures  - • Traits that are morphologically and • functionally similar even though there • is no common ancestor.

9. Analogous structures • look similar • on the outside • same function • different structure & development • on the inside • different origin • no evolutionary relationship

10. Convergent Evolution These animals have evolved similar adaptations for obtaining food because they occupy similar niches. What can you infer about their phylogeny from their geographic locations?

11. Flight evolved 3 separate times— evolving similar solutions to similar “problems” Convergent evolution • 3 groups with wings • Does this mean they have a recent common ancestor?

12. placental mammal marsupial mammal Parallel Evolution filling similar roles in nature, so have similar adaptations

13. Vestigial organs • Structures on modern animals that have no function • remains of structures that were functional in ancestors • evidence of change over time • some snakes & whales have pelvis bones & leg bones of walking ancestors • eyes on blind cave fish • human tail bone

14. Embryology Development of embryo tells an evolutionary story

15. Dog Human Macaque Bird Frog Lamprey 8 32 45 125 67 0 10 20 30 40 50 60 70 80 90 100 110 120 Molecular record • Comparing DNA & protein structure • everyone uses the same genetic code! • DNA • compare common genes • compare common proteins

16. Artificial selection • How do we know natural selection can change a population? • we can recreate a similar process • “evolution by human selection” Wild Mustard

17. Artificial Selection gone bad! • Unexpected consequences of artificial selection Pesticide resistance Antibiotic resistance

18. Insecticide resistance • Spray the field, but… • insecticide didn’t kill all individuals • variation • resistant survivors reproduce • resistance is inherited • insecticide becomes less & less effective

19. Punctuated Equilibrium vs. Gradualism Punctuated-“instead of a slow, continuous movement, evolution tends to be characterized by long periods of virtual standstill ("equilibrium"), "punctuated" by episodes of very fast development of new forms” Gradual-The view that speciation proceeds by imperceptibly small, cumulative steps over long periods of time rather than by abrupt, major changes.