THE HISTORY OF THE EARTH and PREHISTORIC MAN

HISTORY OF THE EARTH Modern Science believes that the EARTH has existed for approximately 4.54 BILLION YEARS. (That is years.) Earth’s HISTORY is divided into many DIFFERENT PERIODS in order to distinguish what was happening on EARTH at the time.

How do we measure the Earth’s Age? The EARTH’S AGE is measured using the GEOLOGIC TIME SCALE, which is basically the BIGGEST TIMELINE EVER.

GEOLOGIC TIME SCALE

UNITS OF MEASUREMENT The Geologic Time Scale uses several different UNITS OF MEASUREMENT. From largest to smallest, they are:  SUPEREONS  EONS  ERA  PERIOD  EPOCH  AGE SUPEREON EON ERA PERIOD EPOCH AGE

Where Are We Now? We are currently in the  PHANEROZOIC eon  CENOZOIC era  QUARTERNARY period  HOLOCENE epoch  SUBATLANTIC age

How Long Have People Walked the Earth? DINOSAURS died off approximately 65 MILLION years ago. The FIRST HUMAN-LIKE HOMINIDS walked the earth approximately 3 MILLION years ago. No matter what you’ve seen on TV or in the movies, HUMAN BEINGS NEVER LIVED AT THE SAME TIME AS DINOSAURS.

A Timeline from 245 MYA to the PRESENT

3 MILLION YEARS AGO… All sorts of ANIMALS existed on the earth. HOMINIDS emerged from PRIMATES. Scientists believe ALL HUMAN LIFE BEGAN IN AFRICA. What were the differences between HOMINIDS and PRIMATES?  Hominids could WALK UPRIGHT.  The BONES in Hominid HANDS were joined differently, allowing more DEXTERITY.

MEET LUCY! We know about the EARLY HUMANS due to the discover of LUCY! LUCY was discovered in 1974 in HADAR, ETHIOPIA. That is in AFRICA. About 40% of Lucy’s SKELETON was recovered. Her SPECIES is called the AUSTRALOPITHECUS. Lucy’s REMAINS are estimated to be 3.2 MILLION years old. She is named Lucy after a song by THE BEATLES.

How did Scientists Learn from Lucy? This is a video interview with DONALD JOHANSON, one of the scientists who discovered Lucy.

How did Scientists Learn from Lucy? Lucy was around 3 FEET TALL and weighed about 50 LBS. We know Lucy was an ADULT because of the WEAR ON HER WISDOM TEETH as well as the WAY HER CRANIAL BONES ARE JOINED. We know Lucy was FEMALE because of LATER FOSSIL DISCOVERIES. She DIED by the EDGE OF A LAKE: did she DROWN? Was she attacked by an ANIMAL?

What might Lucy have looked like when she was alive?

AUSTRALOPITHECUS vs. HOMO ERECTUS

How do we learn about Prehistory? (No one wrote anything down, then!) ANTHROPOLOGISTS are SCIENTISTS who STUDY HUMANKIND, from prehistory to today. To learn about PREHISTORIC MAN, anthropologists use two things:  FOSSILS: REMAINS OF LIVING THINGS  ARTIFACTS: THINGS WHICH WERE MADE BY HUMAN BEINGS

THE STONE AGE and HOMO HABILIS The STONE AGE refers to the period in which HOMINIDS used STONE to make TOOLS. The hominids of this time were called HOMO HABILIS, which means “HANDY MAN”. They were TALLER and SMARTER than Lucy. They were HUNTER/GATHERERS, which means they DID NOT know how to GROW FOOD. Instead they PICKED UP WHAT THEY COULD FIND and HUNTED FOR ANIMALS with their STONE TOOLS. Homo Habilis DID NOT how to MAKE FIRE.

NOMADISM Because HOMO HABILIS were HUNTER/GATHERERS, they could not STAY IN ONE PLACE. They had to MOVE AROUND to find FOOD and ANIMALS TO HUNT. This is called being NOMADIC. Remember: NOMAD=NO HOME

HOMO ERECTUS HOMO HABILIS evolved into a new type of hominid: HOMO ERECTUS Homo Erectus means WALKING MAN. Approx. SAME SIZE as MODERN MAN. HOMO ERECTUS figured out how to MAKE FIRE. COOKING FOOD reduced DISEASE. Homo Erectus gathered around the FIRE and FORMED COMMUNITIES.

TOOL-MAKING SKILLS improved. Started making AXES and KNIVES. No longer had to worry about FREEZING TO DEATH. Began to LEAVE AFRICA approximately 1 MILLION years ago. Did not use BOATS: they crossed the oceans ON FOOT because it was the ICE AGE.

NEANDERTHALS After HOMO ERECTUS came the NEANDERTHALS. Closely related to MODERN MAN. They are named after the NEANDER VALLEY in GERMANY where the first FOSSILS were found. At first assumed to be UNINTELLIGENT and BRUTISH, but this was because they didn’t realize the SKELETON had ARTHRITIS.

NEANDERTHAL NEWS! hal-model-made year-old-bones-article hal-model-made year-old-bones-article Check it out! This was in yesterday’s news! It just goes to show that we are never done learning about Prehistoric Man!

CRO-MAGNON CRO-MAGNON were CONTEMPORARIES of the NEANDERTHALS. This means they LIVED AROUND THE SAME TIME. Cro-Magnon lived in EUROPE. Learned to CURE and STORE FOOD for the WINTERS. Learned to FISH with NETS. Built TRAPS to CATCH FOOD while they were busy doing SOMETHING ELSE. Made CLOTHING and JEWELRY. Invented the BOW and ARROW.

CAVE PAINTINGS A very strange thing the CRO-MAGNON did which NO HOMINIDS HAD DONE BEFORE was PAINT. They painted on the INSIDE of CAVE WALLS. One Cro-Magnon man would ADD TO THE PAINTINGS left by another. Mostly these paintings were of ANIMALS and of PEOPLE HUNTING THEM. Why did the Cro-Magnon do this?  RELIGIOUS CEREMONY?  SYMPATHETIC MAGIC?  RITE OF PASSAGE?  TO SAY “I WAS HERE”, like we do today with grafitti?