C-Notes: Early Earth Stnd: 8e 3/24/2014 Objective: SWBAT identify the slow changes of Earth’s past into manageable units based on major geologic changes.

Is the study of the Earth What is Geology? Is the study of the Earth the materials of which it is made the structure of those materials the processes acting upon the Earth. Certain drugs have become popular among teens and young adults at dance clubs and raves.

A Scottish scientist proposed that the changes he observed in landforms resulted from slow changes over a long period of time, a principle that became known as Gradualism. Who is James Hutton? (Father of Geology) Certain drugs have become popular among teens and young adults at dance clubs and raves.

What is Catastrophism? This theory proposed that unpredictable sudden and drastic events causes geologic change over a large area or sometimes the whole planet. What is one way that a catastrophe has disrupted the history of life on Earth? An asteroid impact formed a debris cloud that blocked the sun and caused the extinction of dinosaurs. Certain drugs have become popular among teens and young adults at dance clubs and raves.

This theory was proposed by Charles Lyell. What is Uniformitarianism? This theory states that the geologic processes that shaped Earth are uniform through time. This theory was proposed by Charles Lyell. This theory soon replaced catastrophism as the favored theory of geologic change. Certain drugs have become popular among teens and young adults at dance clubs and raves.

What important concepts about Earth did Hutton and Lyell agree upon? That changes to Earth’s surface occur slowly and gradually over time. Certain drugs have become popular among teens and young adults at dance clubs and raves.

How old is the Earth? The earth was formed ~4.5 billion years age It took ~500 million years for the crust to solidify. The oldest fossils of microorganisms 3.5 billion years old embedded in rocks in western Australia Prokaryotes dominated from 3.5 to 2 billion years ago. During this time, the first divergence occurred: Bacteria and Archae Oxygen began accumulating in the atmosphere about 2.7 billion years ago.                  a.  Cyanobacteria are photosynthetic prokaryotes that are still present today à produced oxygen. Certain drugs have become popular among teens and young adults at dance clubs and raves.

How old is the Earth? 5.  The oldest eukaryotic fossils are ~2 billion years old.              a.  Symbiotic (related) community of prokaryotes living within larger prokaryotes.   Mitochondria and chloroplasts 6.  The oldest fossils of multicellular organisms are ~1.2 billion years old 7. The oldest animal fossils are ~700 million years old. 8.  Plants, fungi, and animals began colonizing land ~500 million years ago. a.  First plants transformed the landscape… b.  Then animals were able to take advantage of new niches                                Mammals evolved 50 to 60 million years ago. Certain drugs have become popular among teens and young adults at dance clubs and raves.

Early and modern prokaryotes

Fossilized evidence of bacteria  Stromatolites are fossilized bacterial mats. Many fossils of prokaryotes are found in layers that make up the prokaryotic mats.  

Bacterial mats and stromatolites

Fossilized animal embryos from Chinese sediments 570 million years ago.

What is the usefulness of categorizing Earth’s history into the geologic time scale? The time scaled is divided into a series of units based on the order in which different groups of rocks and fossils were formed. Eras Periods Epochs Certain drugs have become popular among teens and young adults at dance clubs and raves.

What is the geological time scale? A “calendar” of Earth’s history that spans 4.6 billion years divided into eras and periods Ex: Precambrian – largest span of time ◦1st 4 billion years of Earth’s history ◦Few fossils Certain drugs have become popular among teens and young adults at dance clubs and raves.

Precambrian Era (3.5 billion years ago) What are the eras that come from early ideas about life forms preserved as fossils? Precambrian Era (3.5 billion years ago) This era makes up about 87% of the Earth’s history Organisms developed the ability to photosynthesize 2.7 billion years ago. Organisms included: Simple unicellular prokaryotes Sponges Jelly fish Why is this important???? Microbes helped produce an oxygen atmosphere through photosynthesis. Certain drugs have become popular among teens and young adults at dance clubs and raves.

Paleozoic Era Lasted until about 245 million years ago Life began to diversify and the fossil records shows many different types of animals and plants Both invertebrates and vertebrates developed during this era Marine invertebrates dominate Jawed Fish Evolve Plants invade land (Oxygen to atmosphere) Insects emerge First Amphibian First Reptiles First winged insect Cambrian Explosion At the end of the Paleozoic Era there was the largest mass extinction on fossil record ~90% of marine life went extinct ~70% of land species went extinct Permian Extinction What are the eras that come from early ideas about life forms preserved as fossils? Certain drugs have become popular among teens and young adults at dance clubs and raves.

What are the eras that come from early ideas about life forms preserved as fossils? 3. Mesozoic Era (Triassic, Jurassic, Cretaceous Periods) Lasted about 66 million years ago Much larger and more complex organisms such as dinosaurs, mammals, and birds developed during this era. Major Changes to the Earth: mass extinction of the dinosaurs separation of the continents Organisms included: Dinosaurs dominate First Birds First Mammals First Flowering plants K-T Mass Extinction Event, 65mya (Cretaceous-Tertiary boundary; Almost all the large vertebrates on Earth, on land, at sea, and in the air became extinct. The End of Dinosaurs) Certain drugs have become popular among teens and young adults at dance clubs and raves.

What are the eras that come from early ideas about life forms preserved as fossils? 4. Cenozoic Era (Tertiary and Quaternary Periods) Includes modern times Includes several Ice Ages Humans developed and became the dominant species on Earth Mammals change Earliest Monkeys Climate becomes drier Panama attaches South America to North America First human hominids Modern Man (That’s us Whoaaaa!!!) Civilization Age of Exploration, Industrial and Computer Age **Eras and periods are determined by what type of organisms lived at that time** Certain drugs have become popular among teens and young adults at dance clubs and raves.

Some major episodes in the history of life.

Clock analogy for some key events in evolutionary history

The Cambrian radiation of animals