what was our planet like a long time ago?. most of the time that people have lived on earth has been...

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Prehistor ic Life What was our planet like a long time ago?

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Page 1: What was our planet like a long time ago?. Most of the time that people have lived on Earth has been during what we call prehistory. Today we live during

Prehistoric LifeWhat was our planet like a long time ago?

Page 2: What was our planet like a long time ago?. Most of the time that people have lived on Earth has been during what we call prehistory. Today we live during

Prehistory vs. HistoryWhat is the difference?

• Most of the time that people have lived on Earth has been during what we call prehistory.• Today we live during the time period

known as history.• When did one end and the other

begin?

• In one word, WRITING.

Page 3: What was our planet like a long time ago?. Most of the time that people have lived on Earth has been during what we call prehistory. Today we live during

Prehistory is the time before writing was

invented.

2000 CE1 CE2000 BCE4000 BCE

3500 BCEWriting is invented in Mesopotamia

Prehistory History

Page 4: What was our planet like a long time ago?. Most of the time that people have lived on Earth has been during what we call prehistory. Today we live during

How do we know what things were like during prehistoric times?

•Fossils•Artifacts

Page 5: What was our planet like a long time ago?. Most of the time that people have lived on Earth has been during what we call prehistory. Today we live during

What is a fossil?• Physical evidence of former life from a time before

recorded human history.

Page 6: What was our planet like a long time ago?. Most of the time that people have lived on Earth has been during what we call prehistory. Today we live during

How do fossils form?

• In order to form, fossils need to have very specific conditions.•Most things do not become fossilized when they die.

Page 7: What was our planet like a long time ago?. Most of the time that people have lived on Earth has been during what we call prehistory. Today we live during

A fish returns to the place of its birth to spawn (make baby fish).

Page 8: What was our planet like a long time ago?. Most of the time that people have lived on Earth has been during what we call prehistory. Today we live during

After spawning, the fish dies, becomes waterlogged, and sinks to the bottom.

Page 9: What was our planet like a long time ago?. Most of the time that people have lived on Earth has been during what we call prehistory. Today we live during

The fish partially decomposes on the sea floor.

Page 10: What was our planet like a long time ago?. Most of the time that people have lived on Earth has been during what we call prehistory. Today we live during

Unstable rocks below the fish slip and cause sediment (sand, dirt, rotting plants) to quickly cover the fish. Under the sediment, bacteria break down the rest of the fish, leaving just the skeleton.

Page 11: What was our planet like a long time ago?. Most of the time that people have lived on Earth has been during what we call prehistory. Today we live during

Over time more sediment piles on top, putting weight on the sediment below and turning it to stone.

Page 12: What was our planet like a long time ago?. Most of the time that people have lived on Earth has been during what we call prehistory. Today we live during

As time goes by the minerals in the skeleton dissolve and are replaced by minerals from the surrounding sediment.

Page 13: What was our planet like a long time ago?. Most of the time that people have lived on Earth has been during what we call prehistory. Today we live during

Millions of years later, geological forces push the rock towards the surface.

Page 14: What was our planet like a long time ago?. Most of the time that people have lived on Earth has been during what we call prehistory. Today we live during

Eventually it rises above sea level and the rock begins to erode, exposing the fish’s head.

Page 15: What was our planet like a long time ago?. Most of the time that people have lived on Earth has been during what we call prehistory. Today we live during

A paleontologist carefully excavates the fossil.

Page 16: What was our planet like a long time ago?. Most of the time that people have lived on Earth has been during what we call prehistory. Today we live during

What they end up with would look like this.

Page 17: What was our planet like a long time ago?. Most of the time that people have lived on Earth has been during what we call prehistory. Today we live during

How do we know what things were like during prehistoric times?

•Fossils•Artifacts

Page 18: What was our planet like a long time ago?. Most of the time that people have lived on Earth has been during what we call prehistory. Today we live during

What are prehistoric artifacts?

Page 19: What was our planet like a long time ago?. Most of the time that people have lived on Earth has been during what we call prehistory. Today we live during

What are prehistoric artifacts?

Page 20: What was our planet like a long time ago?. Most of the time that people have lived on Earth has been during what we call prehistory. Today we live during

What can artifacts tell us about the past?

• The size of spear tips can tell what types of animals people hunted.

• Large spear tips were used to hunt large animals like mammoths or deer.

• Small spear tips were used to hunt small animals like birds and rabbits.

Page 21: What was our planet like a long time ago?. Most of the time that people have lived on Earth has been during what we call prehistory. Today we live during

What are the downsides to just using fossils and artifacts to try to determine what prehistoric life was like?

• Because there were no written records, archaeologists can only take their best guess when studying fossils and artifacts.• Much of what we know about

prehistoric times is just the best guesses of archaeologists.• Some things that people thought 50

years ago have been proven false.

Page 22: What was our planet like a long time ago?. Most of the time that people have lived on Earth has been during what we call prehistory. Today we live during

How do we know about what happened in the world in the time period we know as history?

• Fossils take so long to form that none exist from the time writing was invented.• However, archaeologists still study artifacts.• But now they study them together with oral traditions and written records.

Page 23: What was our planet like a long time ago?. Most of the time that people have lived on Earth has been during what we call prehistory. Today we live during

What are oral traditions?

• Oral traditions are stories about the past that are told and passed from one generation to the next.

• In Africa, the storytellers are called griots.

• Oral traditions are not always accurate. Sometimes they change as they are told and contain exaggerations.

Page 24: What was our planet like a long time ago?. Most of the time that people have lived on Earth has been during what we call prehistory. Today we live during

WRITTEN RECORDS

• What are written records?

• Basically anything can be considered a written record and can be valuable to archaeologists.

• For example…

1. Governmental documents

2. Tomb walls3. Business contracts4. Religious

documents5. Copies of

speeches made by leaders

6. Work done by a student in school

Page 25: What was our planet like a long time ago?. Most of the time that people have lived on Earth has been during what we call prehistory. Today we live during

Imagine, 5,000 years from now someone could be studying your homework to get an idea of what your life is like.