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25 Cards in this Set
- Front
- Back
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Science |
knowledge based on organized observations and inquiries into the natural and physical universe. science investigates evidence found in the natural world and draws conclusions |
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Estimated age of earth |
4.6 billion years old |
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oldest rocks found on earth |
3.8 billion years old |
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estimated age of the oldest fossil evidence and what type of organisms were they? |
3.5 billion years old, prokaryotic bacterial cells |
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Paleontology |
the study of fossil remains or other clues to past life |
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Geologic time scale and two factors used to divide the geologic time scale into eras |
divided earth's history into time periods or eras, periods and epochs. eras are delineated by major geological/biological events including mass extinctions. based on fossil records we can approximate dates using the scale. |
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What is a fossil and what can it tell us about geology? |
any evidence of an organism from more than 10,000 years ago. represent major organisms and give us information from ancient times, but also indicate relationships between different groups of organisms (descent from a common ancestor) |
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Transitional fossil form |
Fossils that may provide evidence of the evolution of one species into another |
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Three reasons why the fossil record is incomplete |
Most organisms do not fossilize, erosion or movements of the earth's crust have destroyed many fossils, many fossils are buried deep in the earth |
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relative dating |
usually by layer - deeper layers are older, nearer the surface usually younger. (not an exact date) |
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absolute dating |
(exact date) radiometric dating techniques using radioactive isotopes to assign an actual date. based on knowing the atoms of the radioactive substance to decay, it is possible to determine a reasonably exact age of the sample. |
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biogeography |
study of distribution of species across the planet |
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Continental drift |
the movement of earth's continents due to the theory of plate tectonics |
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Theory of plate tectonics |
earth's surface is divided into rigid layers that drift/move due to forces working deep in the earth |
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Pangaea |
Continents were once all together in a single large mass |
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Laurasia and Gondwana |
Pangaea eventually separated into two major continents, then into the present day continents which gradually drifted into current positions and continue to move |
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Plate Collision |
turn upward and form mountain ranges or one lay turns under the other to form deep ocean trenches |
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Plates drift |
Molten rock moves upward |
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Biologically, how does continental drift help to set a time line for evolutionary change?
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fossils found on multiple continents indicates the species existed at a time when the continents were together. fossils found on one or a limited number of continents indicates a time after the separation. |
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Homologous structures |
similar structures - bird, bat, whale, cat, horse, human different appearance, but have same bone structure. |
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Vestigial structures |
structures that remain but have no function - ostrich wings, snakes hips, whales pelvis, human tail bone |
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Convergent Evolution |
the development of similar adaptations/function in organisms that don't have an evolutionary relationship. |
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Analogous Structures |
Same function but structurally unrelated - bird wing and insect wing, shark (fish) and dolphin (mammal) fin and tail |
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Developmental Biology |
study of zygote through fetal development through adult life. supports the concept of common descent. |
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Two major groups of cellular chemicals used by evolutionary scientists to study relationships between species |
DNA and protein sequences. all have in common: use same genetic code of four nucleotide for building DNA and the same 20 amino acids to form protein molecules. |
