Download Evolution Study Guide

Evolution Study Guide
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Evolution:
*Biodiversity- Many different species can exist in a particular environment
*Variation- difference in species- there are brown rabbits & there are white rabbits
*Genetic Variation has to come from inherited traits (NOT acquired)
*Mutations- random change to genes. They can be helpful, harmful or sometimes neither
*Darwin- Natural Selection- Galapagos Island, Finches
*Acquired traits- like weightlifting can NOT be passed onto offspring
*Mutations cause variation
*Evolution is CHANGE- new species descend from earlier species
*Environment is the biggest factor that affects natural selection
*Environment also can affect speciation
*Whales evolve from land animals
*Speciation occurs when… (EAR) new Environment, Adapt through natural selection, can NO longer
Reproduce with that species.
Earth’s History:
*Extinction of species can be from… environmental changes, loss of food source, disease
*We have had millions of species on Earth. However, 99% of every living thing that was on Earth is now
extinct.
*Geologic time periods are divided by the appearance & disappearance of life forms (mass extinction)
*Endangered Species- the species has a high risk of becoming extinct
*Single-celled (bacteria) organisms have lived on Earth the longest. They have existed since Precambrian Time
*B FARM B- order of organisms from oldest to youngest. Bacteria, Fish, Amphibians, Reptiles, Mammals,
Birds
*Humans live in the Cenozoic Era- Modern man first appeared approximately 100,000 years ago
*Explosion of Life = Paleozoic
*Age of Mammals = Cenozoic
* Age of Reptiles = Mesozoic
*The mass extinction that ended the Mesozoic Era was the meteorite hitting the Earth
*Precambrian Time took up the most time in Earth’s history- 88%
*Modern Nebular Hypothesis is the theory of how the solar system was formed
*Big Bang is the theory of how the universe was formed
Geologic Time
*Fossils can be… imprints, molds, cast, or an insect trapped in amber
*Law of Superposition- In layers of sedimentary rock, the oldest rock is on the bottom the newest is on top.
*Relative age- comparison- an event is older or younger. It is determined by law of superposition or index
fossils
*Paleontologist study fossils
*Absolute age- date in years- Example the igneous rock is 2.5 million years old. This is found by radioactive
dating.
*Half Life- Used in radioactive dating to determine the absolute age of a rock. Half-life of a radioactive
element is the time it takes for half of the radioactive atoms to decay.
*Observation- Can be supported by facts. Example the fossil of the footprint has 3 toes
*Inference- An assumption based on your facts. The footprints look like they were running
*Catastrophism- sudden event that will change the surface of the Earth- Meteorite
*Uniformitarianism- slow event that changes the surface- Erosion & Deposition
* Using this geologic column the oldest layer is E, B, C, D, A youngest layer- Remember intrusions are always
younger than the rock surrounding it.