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27 Cards in this Set
- Front
- Back
Evolution |
The process by which populations accumulate inherited changes over time. |
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Adaptation |
A trait that allows an organism to survive and reproduce in its environment. |
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Common Ancestor |
An organism that is related to two or more species in their evolutionary history. |
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Fossil Record |
All of the information that comes from fossils. Fossils are the primary piece of evidence to support evolution because they are tangible remains of ancient organisms found in rock. They are evidence of past life. |
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Comparative Anatomy |
Observing the similarities in body structure amongst different organisms. |
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Homologous Structure |
Two organisms have similar structures or body features. Scientists compare basic body plans and how parts are arranged to tell how closely related organisms are ex.) A cat's leg and a whale's flipper are similar to a human's arm bone |
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Vestigial Structures |
Remnants of a once useful anatomical structure. A body feature that used to be important but is no longer used. ex.) Whales still have a pelvis and femur, which it no longer uses |
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Embryonic Evidence |
Observing organisms before they are born or hatched. Adults can look very different, but in the early developmental stages they are similar. You can see similarities in any multi-cellular animal in a developmental stage proceeding birth or hatching. |
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Species |
A classification in biology for a group of similar organisms that can reproduce. |
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Natural Selection |
Organisms with adaptations survive and pass those traits on to offspring.
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Law of Superposition |
The deeper you go into the layers of the Earth, the older the rocks and fossils will be. A fossil found in the bottom layer is presumed to be older than a fossil found in the middle or top layer. |
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Mechanisms of Natural Selection |
Variance - differences Over-production - having lots of babies Competition - resources are limited Reproduction - best adapted survive & pass on genetic material to offspring |
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Speciation |
How a species evolves into a new species over time. |
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Limiting Factors |
Factors in the environment that stop an organism from increasing in population such as lack of food, predators, disease. |
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Variation |
Unique combinations of traits within a group of organisms. |
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Factors that cause speciation |
Separation - geographic boundaries Adaptation - 2 populations evolve different Division - 2 populations can no longer produce offspring together. Creation of separate species |
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How do limiting factors cause natural selection? |
There is only so much food, water & shelter to go around. There is competition for resources. Whoever is best at getting their needs met will survive and reproduce. |
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Why must there be variation in a population for natural selection to occur? |
Differences allow individuals to be better adapted for their environment & survive. Helpful variations gradually increase in a species. Non-helpful variations disappear. |
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Fitness |
The ability to survive and produce offspring who can also survive reproduce. |
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How did whales evolve? |
Whales evolved from even-toed land animals. Fossil evidence shows that whales evolved from mesonychids, a dog-like land living animal changed into a water living animal. DNA evidence shows the whale has similar DNA to the mesonychid. Comparative anatomy shows the whale has a common ancestor with land animals because whales still have a pelvis and femur. The whale once had hind legs and used to walk on land. These are vestigial structures; no longer used. Whales also have homologous structures to land based animals. The flippers are similar to the forearms and hands of humans. |
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Classification |
The arrangement of organisms into groups based on the characteristics they have in common. |
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Why do scientists classify things? |
To help understand how many different species exist, what the characteristics of those species are, and how those species relate to each other. |
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Seven levels of classification (biggest to smallest) |
Hint: King Phillip Came Over For Grape Soda Kingdom Phylum Class Order Family Genus Species |
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Binomial Nomenclature |
System of using 2 terms (Genus Species) to identify organisms |
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How did Charles Darwin come up with his theory of evolution? |
Observing the diversity of living organisms on the Galapagos Islands. Species on an island face different conditions than those on the mainland. Darwin hypothesized that the species gradually changed over time to adapt to new conditions. ex.) Finches have different beaks based upon their environment |
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5 types of evidence scientists use to understand evolution |
Fossil Record Homologous Structures Vestigial Structures Embryonic Evidence DNA |
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How is DNA used to understand evolution? |
If species inherited many of the same genes from a common ancestor they they would have similar body structures and development. The more similar the DNA pattern, the more closely related the two species are. |