1. Timeline of the Earth

2. The 4 Eras of History The Precambrian Era: began 4.5 billion years ago
The Paleozoic Era: began 545 million years ago
The Mesozoic Era: began 245 million years ago
The Cenozoic Era: began 65 million years ago

3. The 4 eras can be subdivided into Periods, and then again into Epochs

4. Precambrian Era
Precambrian Era

5. Earth created – 4.5 billion years ago
Precambrian Era

6. 4.4 billion years ago
The giant-impact hypothesis, sometimes called the Big Splash, or the Theia Impact suggests that the Moon formed out of the debris left over from a collision between Earth and an astronomical body the size of Mars, approximately 4.5 billion years ago
Precambrian Era

7. Oceans, Oxygen, Rocks
Large basins were formed, eventually filled with water (oceans)
The crust was formed and was split into 'plates’
Oceans became home to bacteria which eventually put oxygen into the water
Lots of volcanic activity and mountain building; the Canadian Shield is made
Precambrian Era

8. What did Earth look like then?
Precambrian Era

9. 541 millions years ago
The Precambrian era ends with a global ice age and life-forms more complicated than bacteria were evolving
The “Cambrian Explosion”: a relatively short time where life diversified and evolved into much more complicated forms
Precambrian Era

10. Paleozoic Era
Paleozoic Era

11. Paleozoic Era – 541 million years ago
Fish, amphibians and reptiles all evolved during this era
Life started in the oceans but moved onto land
Great forests of primitive forests covered the continents
The Appalachian mountains are made
Africa was down near the south pole
Paleozoic Era

12. What the Earth looked like then
Earth: 300 mya
Paleozoic Era

13. 252 million years ago
The Paleozoic era ends with a mass extinction called ‘the Great Dying’
70-95% of all species went extinct
Scientists don’t know exactly why, it could have been rapid climate change, or an asteroid hitting Earth
The continents are now all part of Pangaea
Paleozoic Era

14. Mesozoic Era – 252 million year ago

15. Mesozoic Era – 252 million year ago
Pangaea breaks apart
Called the ‘Age of the Dinosaurs’
Mesozoic Era

16. What the Earth looked like then
Mesozoic Era

17. Stegosaurus
Lived million years ago
30 feet long
Mesozoic Era

18. Sarcosuchus An extinct kind of crocodile, the largest crocodile ever
It lived 112 million years again Africa and South America
It was almost twice as long as the modern crocodile and weighed up to 8 tons and was 38 ft long
Mesozoic Era

19. Argentinosaurus It is the largest dinosaur ever
It lived million years ago
Was about feet long
Mesozoic Era

20. Tyrannosaurus It lived 67-66 million years ago 40 feet long
One of the largest land predators ever
Mesozoic Era

21. 66 million years ago
The Mesozoic Era ends with another mass extinction, most of the dinosaurs killed off
Some scientists believe it was a large asteroid impact, others believe it was a mass volcanic event
Nearly every animal over 50 lbs was killed off
Mesozoic Era

22. Cenozoic era
Cenozoic Era

23. Cenozoic Era – 66 million years ago
The continents move into their current positions
Called the ‘Age of Mammals’
Cenozoic Era

24. Titanoboa
An extinct snake that lived approximately 60–58 million years ago
It was the largest, longest, and heaviest snake ever discovered
It reached a maximum length of 40 to 50 ft and weighed about 2,502 lb
Lived in South America
Cenozoic Era

25. Paraceratherium The largest land mammal ever
It weighed 12 tons, and was 16 ft tall at the shoulders and 26.2 ft long
It was an extinct type of gigantic hornless rhinoceros-like mammal
Lived 33.9 million to 23 million years ago
Cenozoic Era

26. Gigantopithecus An extinct type of giant ape
It lived 9 million years ago to 100,000 years ago
The largest ape ever, it stood nearly 10 feet tall and weighed over half a ton
Cenozoic Era

27. Stupendemys An extinct kind of giant turtle, the biggest turtle ever
It lived in South America about 6 to 5 million years ago
Its shell was 11 ft long
Cenozoic Era

28. Argentavis Magnificens
Largest bird ever
Lived approx. 6 mya
Cenozoic Era

29. Megatherium
A type of elephant-sized sloth, it lived in Central and South America
Lived 3 million years ago until 10,500 years ago
One of the largest land mammals ever
Weighing up to 4 tons and up to 20 ft in length (
Cenozoic Era

30. Josephoartigasia monesi
The biggest rodent ever, an extinct kind of South American giant rat
It lived 4 to 2 million years
It weighed 2,200 lbs and was 10 feet long
Cenozoic Era

31. Elasmotherium An extinct kind of giant rhinoceros
Lived 2.6 million years ago to 50,000 years ago
It was the size of a mammoth and is thought to have had a large, thick horn on its forehead 
Cenozoic Era

32. Smilodon The best known saber-toothed cat
It lived in North America 2.5 million years ago–10,000 years ago
Cenozoic Era

33. Homo Habilis 2.3 to 1.4 million years ago
It stood 3-4 feet tall and had super long arms compared to modern humans
They had small brains but used primitive stone tools
Cenozoic Era

34. Dire Wolf 1.8 million years ago – 10,000 years ago
Lived in North America
Like a modern gray wolf except much bigger, 5 feet long
Cenozoic Era

35. Homo Erectus 1.8 million years ago -143,000 years ago
It started to look like modern humans
Found outside of Africa in Eurasia
Its brain was a bit smaller, they stood nearly 6 feet tall
They discovered fire ad were fully bipedal
They evolved from Homo Habilis
Cenozoic Era

36. Cenozoic Era

37. Homo heidelbergensis
It lived in Africa, Europe and western Asia from 600,000 years ago to 200,000 years ago
It went extinct
They are our ancient cousin but probably not our ancestor
They were very tall, around 7 feet tall
Cenozoic Era

38. Neanderthal Lived 600,000 years ago – 35,000 years ago
Lived in Western Europe and central Asia during the Ice Age
They are not our direct ancestor and went extinct
Theories say they probably mated with Homo Sapiens, many people have small percentage of Neanderthal DNA
They made tools and had a language
Cenozoic Era

39. American Lion
Lived in North America 340,000 years ago – 11,000 years ago
One of the largest types of cat ever
Cenozoic Era

40. Homo Sapiens They evolved from Homo Erectus about 200,000 years ago
They had a language, complicated tools, and complex social structures
Cenozoic Era

41. Woolly mammoth Cenozoic Era
A bit bigger than modern elephants, they stood 9-11 feet tall at the shoulder and weighed up to 6 tons
It lived at the same time as early humans, who hunted it for food and for its tusks
Lived from 150,000 years ago to just 10,000 years ago, when it died off from climate change and hunting by humans
Isolated populations survived on Wrangel Island in northern Russia until 4,000 years ago
It has been proposed the species could be recreated through cloning
Cenozoic Era

42. Homo Floresiensis Lived 95,000 – 17,000 years ago
An extinct ancient cousin of ours
They used stone tools and fire and hunted dwarf elephants also found on the island in Indonesia
They were only 3 feet tall and nicknamed ‘hobbits’
Cenozoic Era

43. Dodo
An extinct flightless bird that lived on the island of Mauritius in the Indian Ocean
Humans destroyed their habitat and food source
The pigs and dogs that we introduced to the island also killed many of them
The last dodo died sometime in the late 1600s
Cenozoic Era

44. Tasmanian Tiger It looked like half tiger half dog
It lived on the island of Tasmania off Australia
The tiger was hunted to extinction by humans
The last one was caught in 1933 and died three years later in a zoo
Cenozoic Era

45. Baiji white dolphin It lived in the Yangtze River in China
Humans had overhunted it
It was last seen in 2007
Cenozoic Era

46. West African Black Rhino
The rarest of the black rhino subspecies is now extinct
Listed as "critically endangered" in 2008, but a survey of the animal's last remaining habitat in northern Cameroon failed to find any sign of the rhinos, either a true sighting or even evidence of its presence, like feces
No West African black rhinos are known to be held in captivity.
Cenozoic Era

47. Are we in a fifth era now?
Many scientists now use the term “Anthropocene era” to describe our current era
It began when human activities started to have a significant global impact on Earth's geology and ecosystems (2,000 years ago)
Humankind has entered what is sometimes called the Earth's sixth major extinction
Anthropocene Era

48. Future Human Evolution

49. How Have We Evolved?
Modern humans are less hairy, we have smaller molars, and are taller
We still have leftovers from when we were monkeys, like goose bumps, extra ear muscles, wisdom teeth, a tailbone, and an appendix

50. Evidence of Evolution in our bodies

51. How Will We Evolve?
Try and guess what will happen to us. Think about how most modern humans live: indoors, much easier and sedentary lives, less exposure to elements
With a partner/small group, try and think of ways that humans might evolve in the future. What will happen to our bodies?

52. 1) Mono-Ethnicity
We will all become the same race as we continue to intermarry

53. 2) Poor Immune Systems
As we rely more and more on medication to stay healthy, our immune systems will have less to do and become weaker

54. 3) Muscle Atrophy
Our muscles will get smaller as we move around less

55. 4) Increased Height
Human height has been growing rapidly for the last two centuries.
Over the last 150 years alone, the average height of the species has increased by 10cm.
It is believed that the main driving force behind this growth is the abundance of nutrition available to many of us

56. 5) Less Hairy
Hair was originally to protect our bodies from the elements. But now we are not exposed to the elements as much, and we are becoming less hairy.

57. 6) Smaller Teeth Our teeth will get smaller
Evidence has shown that in the last 100,000 years alone, our teeth have halved in size

58. 7) Fewer Toes
Our other toes – especially the biggest – serve to aid balance and walking, our little toes serve no purpose, and humans can get by very well without them

59. 8) Bigger Heads

60. 9) Longer Lives
Some scientists are predicting that 2050 people could grow to be 120 years old

61. What we might look like in 100,000 years

62. Or maybe like this?

63. Or this?

64. Or like this?

65. One scientist’s theory
If we move to a low-gravity planet, we could develop longer arms and legs leaving us looking more like orangutans.
If we enter another Ice Age we would develop larger heads and noses to deal with low temperatures and would become physically more powerful, particularly males, as the fight for resources increased.
If ocean levels rise humans could develop webbed hands and feet, more fat and eyes like those of cats to help us see in the murky depths of the ocean.