The Big Bang Theory  Many scientists believe that the Earth was formed at the same time as many other planets About 4.6 billion years ago  After a massive explosion, rock, dust, and ice began being pulled together by gravity forming the Earth

EARLY EARTH This artist’s illustration shows Earth shortly after the moon formed. Notice the rocky objects striking Earth from space, and the molten rock overflowing the surface.

Earth Origins FeatureEarly EarthLater Pre-Cambrian AtmosphereHelium and HydrogenN, CO 2, water vapor ContinentsNone (Earth was molten) Less dense material began to cool and form land masses known as continents OceansNone (too hot)As the surface cooled, water vapor began to condense to form rain. Gradually, rain water began to accumulate and form oceans

Atmosphere

The Beginning of Life  Scientists have found fossils of single- celled organisms Believed to have formed about 3.5 billion years ago Probably similar to present-day bacteria  Scientists hypothesize that all other forms of life on Earth arose from these simple organisms Early organisms lived only in water

Life Moves on Land  About 2.5 billion years ago, many organisms began using energy from the sun to make their own food Processes in the atmosphere changed some of this O 2 into a form called ozone (O 3 ) The atmosphere developed a layer rich in ozone that blocked out the deadly UV rays This allowed organisms to survive on land

LAB!!!

Earth History Timeline  See NJ ASK Coach Book for timeline….copy into notebook!!!  Know major ERAS and PERIODS of Earth’s history!

Key Ideas and Vocabulary  How do fossils form? How do fossils form?  What are the different kinds of fossils? What are the different kinds of fossils?  What does the fossil record tell about organisms and environments of the past? What does the fossil record tell about organisms and environments of the past? Terms  fossil fossil  sedimentary rock sedimentary rock  mold mold  cast cast  petrified fossil petrified fossil  carbon film carbon film  trace fossil trace fossil  paleontologist paleontologist  scientific theory scientific theory  evolution evolution  extinct extinct

 Fossil-the preserved remains or traces of living things

Fossils  Fossils found in rock include: molds and casts petrified fossils carbon films and trace fossils  Other fossils form when the remains of organisms are preserved in substances such as tar, amber, or ice.

Fossils  Fossils are usually found in sedimentary rock  They provide clues to the past  sedimentary rock- type of rock that is made of hardened sediment Examples: sandstone, coal, limestone

 Scientific Theory- well-tested concept that explains a wide range of observations  Evolution- the process by which all the different kinds of living things have changed over time  yandbehavior/humanevolution/preview.w eml yandbehavior/humanevolution/preview.w eml

Who was Charles Darwin?

Darwin’s Journey  December 1831 at 22 years old, Darwin set sail on the British ship HMS Beagle Became the ship’s naturalist Studied plants, animals, and everything about the natural world  Darwin’s most important observations: Diversity of living things Remains of ancient organisms Charcteristsics of organisms on the Galapagoes Islands

Making Connections  On his journey, Darwin observed that there were similarities between the organisms on South American and the Galapagos Islands However, there were important differences…

Mainland vs. Island Mainland IguanasGalapagos Iguanas

Comparisons between the islands ADAPTATIONS

READ ONLY SLIDE Evolution  Darwin reasoned that plants or animals that arrived on the Galápagos Islands faced conditions that were different from those on the mainland. Perhaps, Darwin hypothesized, the species gradually changed over many generations and became better adapted to the new conditions. The gradual change in a species over time is called evolution.evolution.

Evolution  Evolution- The gradual change in a species over time Now that Darwin had a theory, he needed to find out how evolution worked  A main component to his theory was natural selection

Natural Selection  The process by which individuals that are better adapted to their environment are more likely to survive and reproduce than other members of the same species  yandbehavior/naturalselection/preview.w eml yandbehavior/naturalselection/preview.w eml

Overproduction and Variation Natural Selection

Competition and Selection

 Other factors tht contribute to evolution include: Environment Genetic factors ○ Science was not far enough along for Darwin to be able to explain variations in genes in relation to evolution

Evidence of Evolution  Fossils  Patterns of early development  Similar body structures All provide evidence that organisms have changed over time

Early Development Similarities

Similarities in Body Structure

Look at the drawing below of the bones in a crocodile’s leg. Compare this drawing to the previous slide. Do you think that crocodiles sahare a common ancestor with birds, dolphins, and dogs? Support your answer with evidence.