The following is part II of III for my final Geology 100 paper. It's on Evolution. I had to answer 3 questions in 2 paragraphs. The questions were roughly.
1. Describe the main types of life during the 4 geologic eras and show an understanding of the Geologic timeline.
2. Describe what causes and what can destroy fossils.
3. Describe some theories on mass extinctions, like the one that killed the dinosaurs.
Paper to be graded on accuracy, grammar, and original thought.
“Oh, Evolve Already.” Someone I once knew had that saying for a bumper sticker. In the interest of not looking stupid, I never asked what it meant, and at the time didn’t really understand it. As the years passed I finally understood, and to this day I have yet to encounter a single phrase that said so much by saying so little. We think it all began about 4.5 billion years ago, an almost incomprehensible amount of time, with the first single cell life forms arriving about 1 billion years later. This period is known as the Precambrian Era. Geologic time is categorized into 4 Eons, 4 Eras, 12 Periods, and 7 Epochs. Most persons are more familiar with Periods, like the Jurassic, which occurred during the Mesozoic Era and is popularized as the time of the dinosaurs. Prior to the Mesozoic Era was the Paleozoic Era, a time when the first fish and reptiles appeared. We are now living in what is known as the Cenozoic Era, which began around 65 million years ago with the appearance of mammals, and is the youngest of all Eras thus far. The most current breakdown in geologic time looks like this: Phanerozoic Eon>Cenozoic Era>Quaternary Period>Holocene Epoch.
Eventually all living things cease to live. For a fossilized record of that life to be preserved, certain things need to happen. Firstly, the deposition needs to occur in a sedimentary environment. Secondly, those remains need not be disturbed. Unless circumstances provided an absolutely ideal environment for the preservation of the organism, finding a complete fossil is rare because predators/scavengers and a host of other variables tended to scatter whatever remains that were left exposed. Geologic activity also has a huge impact on whether a fossil will “survive”. Things like compressive stress, volcanic activity, and earthquakes could destroy an existing fossil or alter the existing conditions and prevent the fossilization process from occurring. Fossils have taught us much about Earths’ history, like the age of particular rocks and also the types of organisms that preceded us in history. Before the discovery of fossilized dinosaurs, they weren’t even known to have existed. It is believed that that the myth of dragons came about from ancient civilizations having seen dinosaur fossils or their footprints. We know for a fact that dinosaurs are no myth and that they inhabited this planet for a couple hundred million years. What we don’t know for sure however, is how the entire species suddenly vanished about 65 million years ago. My research indicates that they had become a slovenly, decadent society with no real direction or central leadership, living a gluttonous free-for-all existence. Then one day a Stegosaur named Jim “Spike” Jones said he had found the meaning of life and would lead them all to a thing he called salvation. “It’s right here in this liquid mixture I have named “Kool-Aid”, and if you drink aplenty from this cup, it shall set you free.” The rest is ancient history. Then again, there are those who think an asteroid, or a polar reversal of our magnetic poles was the causative factor. I’ll leave that for you the reader to decide.
