Evolution: Change Over Time

1. Evolution: Change Over Time Evolution: Change Over Time The Evidence The Evidence Evolution: Change Over Time Evolution: Change Over Time The Evidence The Evidence

2. Fossil Record • Defined: Collection of every known fossil • Most fossils found in sedimentary rock • Age determined by depth • Law of Superposition: new rock forms on top of older rock • Evidence Conclusions: • 1) Newer fossils are more complex • 2) Common ancestors: similarities between ancient & modern life

4. Comparing old fossils to modern life shows change Ancient Kelp Modern Kelp

5. Carbon Dating helps determine age of fossils Radiometric Dating

7. Timelines like this are accurate, but the scale of time it too massive for us to visualize…So let’s try a different scale of time

8. 24 Hour Life Timeline Scale: 1 minute = 3 million years This timeline shrinks Earth’s existence to a 24 hour day. We all can visualize 24 hours.

9. Fossils show that the oldest life is ~3.5 byo…bacteria

10. 24 Hour Life Timeline Scale: 1 minute = 3 million years Bacteria (3.5 billion)

11. Fossils show the first vertebrates (fish) lived ~510mya.

12. 24 Hour Life Timeline Scale: 1 minute = 3 million years Fish (510 million) Bacteria (3.5 billion)

13. Fossils show the first land animals (amphibians) lived ~340mya

14. 24 Hour Life Timeline Scale: 1 minute = 3 million years Amphibians (340 million) Fish (510 million) Bacteria (3.5 billion)

15. Fossils show that reptiles first lived ~310mya

16. 24 Hour Life Timeline Reptiles (310 million) Scale: 1 minute = 3 million years Amphibians (340 million) Fish (510 million) Bacteria (3.5 billion)

17. Fossils show that mammals and dinosaurs first lived ~250mya

18. Dinosaurs & mammals (250m) 24 Hour Life Timeline Reptiles (310 million) Scale: 1 minute = 3 million years Amphibians (340 million) Fish (510 million) Bacteria (3.5 billion)

19. Fossils show that flowering plants and birds first lived ~175mya

20. Dinosaurs & mammals (250m) 24 Hour Life Timeline Reptiles (310 million) Scale: 1 minute = 3 million years Amphibians (340 million) Flowers and birds (175 m) Fish (510 million) Bacteria (3.5 billion)

21. Fossils show that humans first lived ~200,000 years ago

22. Dinosaurs & mammals (250m) 24 Hour Life Timeline Humans (200,000) Reptiles (310 million) Scale: 1 minute = 3 million years Amphibians (340 million) Flowers and birds (175 m) Fish (510 million) Bacteria (3.5 billion)

23. Dinosaurs & mammals (250m) Other Notable Events First plants (aquatic) Reptiles (310 million) Humans (200,000) Obvious conclusion: Life began very simple and gradually became more complex Scale: 1 minute = 3 million years Amphibians (340 million) Flowers and birds (175 m) Fish (510 million) Bacteria (3.5 billion) Dinosaurs extinct Unicellular eukaryotes

24. Cool Website http://learn.genetics.utah.edu/content/variation/time/index2.html

25. AKA: Transition Fossils Archaeopteryx: shares both bird & reptile features Basilosaurus: shares whale & land mammal features Tiktaalik: shares fish & amphibian features Evidence Conclusion : Indicates common ancestry Missing Link Fossils Whale Evidence Long spine Found in dried up oceans Amphibian evidence Eyes on top of head Wrist bones Reptile Evidence Teeth Bony tail Fish evidence Scales Fins Found in dried-up oceans Land Evidence Wolf-like teeth Hind legs Bird Evidence Wishbone Feathers

26. Vestigial Structures • Defined: Organs which have lost most or all their original function • Vestigial Human Parts: • Gill slits = once used to breath oxygen in water • Yolk sac = once used to nourish developing embryo • Tailbone = once used for balance • Appendix = once used to digest plants • Wisdom teeth = once used to grind plant tissue • Evidence Conclusion : Indicates common ancestry

27. Human Embryo w/ Vestigial Structures

28. Pythons have tiny femurs (leg bone)

29. flipper arm leg wing Homologous Structures walking flight grasping swimming • Defined: similar body structures with very different functions • Different environments lead to adaptations • Ex: The forelimbs of animals • Evidence Conclusion : Indicates common ancestry

30. Biochemical Evidence • DNA, RNA, proteins compared • Genetic code same for most life • More related species have more similar biochemistry • Evidence Conclusion : Indicates common ancestry

31. Embryo Development • Different species show similar development patterns • Different body plans become noticeable later in development • Evidence Conclusion : Indicates common ancestry

32. Antibiotic Resistance • Antibiotics: drugs designed to kill bacteria • Obtained from fungi • Antibiotic Resistance: Bacteria are adapting to the use of antibiotics • Misuse of antibiotics speeds up the process • Importance: Bacteria infections are becoming harder to treat • Example of natural selection Bacteria Fungus

33. Most bacteria killed Strong Survive Bacterial Resistance Strong Reproduce

34. Antibiotic Resistance Bad Good The antibiotics don’t kill the bacteria, that’s why there is no clear area around them. The antibiotics kill the bacteria, so the area around them are clear

36. Pesticide Resistance • Pesticides • Chemicals designed to kill pests (rodents, insects, etc…) • Pesticides sprayed on crops to kill pests • Pesticide Resistance: pests are adapting to the use of pesticides • “Strong” pests survive to reproduce • Importance: Crops are being destroyed by pests • Great example of natural selection "crop dusting"

38. Review • How does antibiotic and pesticide resistance show natural selection? • How do the following lines of evidence show change over time? • Fossils • Homologous structures • Vestigial structures • Resistant organisms • Embryo development • Biochemical evidence • Fossil age can be determined two ways. What are they?