1. History of Life Part 3

3. Proterozoic Eon 2.5 bya – 543 mya
stable continents first appear
Most life are Bacteria and Archaeans
first evidence of oxygen build-up in the atmosphere
This global catastrophe spelled doom for many bacterial groups
&
made possible the explosion of eukaryotic forms.

4. Endosymbiosis The rise of Eukarya 1.8 bya
What does it mean?
Endo = within sym = together
biosis = life Endosymbiosis = organisms of a different species living together, with one of the organisms living within the other
Symbiosis between different species of eubacteria
&
between archeabacteria and eubacteria
The rise of Eukarya 1.8 bya 4 4

5. Prokaryotes lead to Eukaryotes5 5

6. Endosymbiosis Increases Organism Complexity

8. Croanoflagelado: -last unicellular ancestor of all eukaryotes
-Characteristics similar to modern protista 8

10. 800 mya: 1st-multicellular organism
Sphaeroeca, a colony of choanoflagellates
~230 individuals cooperatively linked protists 10

12. 850 MYA First Fungi
Amber fossils
the fossil on right are fungal filaments resemble living filaments of common Candida species. the fossil at right has preserved the perithecium with spores used for reproduction.

13. 760 MYA-First Animal
Otavia antiqua -a sea spongue

14. 14 14

15. Typical day in a late PreCambrian sea…15 15

16. Trilobites: the 1st exoskeletons.16

17. Cambrian Explosion: ~570mya- 500mya
Finally the ocean is full of animals with hard parts… by the early Paleozoic there are lots of animals that can form fossils.
Cambrian Explosion: ~570mya- 500mya 17 17

18. Cambrian Explosion: A sudden explosion of complex, multicellular life at the beginning of the Paleozoic
Many of these early animals looked very strange, unlike any animals we find on Earth today. 18

19. Opibinia… 1st macroscopic predator19 19

20. Most of the major phyla originated over several million years during the early Paleozoic…20 20

21. 520 mya
Pikaia: 1st Chordate 21

22. 22 22

23. Typical day in late PreCambrian sea…23 23

24. Jawless Fish
Earliest Fish 500 mya 24

25. Armored Fish 25

26. Lobed Finned Fish 26

27. 27

28. Plants Move Onto Land 28

29. 480 MYA- First Land Plant
The cryptospores are the oldest land plant fossils found. Petrified fossils

30. Animals Move Onto Land 30 30

31. 31

32. 32 32

33. Fish to Amphibian

34. 370 mya: Amphibians
Tiktaalik:
fish-amphibian transition fossil 34

35. 35 35

36. ~310 mya 1st REPTILES first animals with backbones able to live on dry land Ex Thecodont

37. Earliest Dinosaur Eoraptor 230 mya Argentina 3 ft long 10 lbs Carnivor
“dawn theif”
230 mya
Argentina
3 ft long
10 lbs
Carnivor
Bipedial 37

38. How is a dinosaur different from a reptile?38

39. Flying Reptiles Appeared ~ 230mya, around the same time as dinosaurs.
They were the first vertebrates to fly. 39

40. 40

41. 41

42. Georgia
Eoraptor site 42

43. Reptiles to Mammals

44. Earliest Mammal Megazostrodon found in Africa ~ 220 mya
mega-large, zostros-girdle odon-tooth
found in Africa
~ 220 mya
4-5 inches long
Carnivore
Laid eggs 44

45. Reptiles to Birds 45

46. most small theropod dinosaurs were covered in feathers.46

47. 47

48. 48

49. Earliest Bird
Archaeopteryx
“Ancient wing”
~150 mya 49

50. 50

51. The late Cretaceous was a time of intense volcanic activity.
For many millions of years the atmosphere was modified by the release of volcanic gases and ash. 51

52. Major Extinction Event
65 mya
65% all species become extinct, including all non-avian dinosaurs
Worse for large animals
Marked the end of the Mesozoic 52

53. 53

54. Impact at Chixulub in Yuccatan Peninsula54

55. Post Ice Age: Large Mammals Ground Sloth: 20 mya

56. first to travel long distances & use fire 2.5 MYA- Homo habilis
175,000 yr ago- Homo sapiens
1.8 MYA- Home erectus
first to travel long distances & use fire
2.5 MYA- Homo habilis
First tool user
3.9 MYA- Australopithecus
afarensis
First bipedalism