1. Prehistoric What was here and how do we know??

2. Prehistoric Times  “prehistoric” refers to the time period before written word.  There was time when there was no language.  There was a time when there was language but no writing, no books and no “written history”.

3. If there was no written history…how do we know what happened???  Archaeologists study the remains of ancient civilizations  They study artifacts and ecofacts/fossils  Ecofacts/fossils are the natural remains left behind.  Artifacts are man made remains left behind.

4. Ecofacts vs. Artifacts  An artifact is something made by man. Examples PotteryToolsWeapons Ceremonial remains Ceremonial remains Cave drawings ClothesJewelry ◊An ecofact is something natural from a living thing, plant or animal. Examples Bone Tooth Imprint FOSSILS

5. Ecofact vs. Artifact

6. Just how old are they?  Scientists have created a test to evaluate the age of an artifact/ecofact. .  Carbon 14 dating.  Carbon is in all things.  When something dies it begins to lose its carbon at a specific rate.  How much carbon the item has left tells how long ago it was alive and when it began losing carbon

7. Putting together the pieces  Archaeologists piece together different remains to determine the characteristics of a culture. The shape of their teeth tells that they ate. Their homes tell whether they moved or stayed in one place. The size of their spears tell us what animals they ate.

8. Measuring Time  There are two time periods in history. BCE (BC) Before Common Era (Before Christ) CE (AD) Common Era (Anno Domini-In the Year of our Lord) The change over occurred at the birth of Christ. Everything before Christ is BCE (BC) everything since is CE (AD). We are in 2006 CE (AD)

9. Centuries  A century is an increment of 100 years.  A century starts a year 1 and goes to year 100. Example 1901-2000 or 2001-2100.  We are in the 21 st Century  You were born in the 20 th Century

10. Decades  A decade is an increment of 10 years.  A decade starts at 0 and goes to 9. Example 1990-1999 or 1980-1989.  You were born in the 90’s.  I was born in the 70’s.