Timeline of the Earth

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

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

Precambrian Era Precambrian Era

Earth created – 4.5 billion years ago Precambrian Era

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

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

What did Earth look like then? Precambrian Era

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

Paleozoic Era Paleozoic Era

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

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

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

Mesozoic Era – 252 million year ago

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

What the Earth looked like then Mesozoic Era

Stegosaurus Lived 155-150 million years ago 30 feet long Mesozoic Era

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

Argentinosaurus It is the largest dinosaur ever It lived 97-94 million years ago Was about 70-85 feet long Mesozoic Era

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

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

Cenozoic era Cenozoic Era

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

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

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

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

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

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

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

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

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

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

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

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

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

Cenozoic Era

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

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

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

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

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

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

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

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

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

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

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

Future Human Evolution

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

Evidence of Evolution in our bodies http://www.vox.com/2016/3/17/11250962/proof-evolution-vestigial

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?

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

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

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

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

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.

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

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

8) Bigger Heads

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

What we might look like in 100,000 years

Or maybe like this?

Or this?

Or like this?

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.