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26 Cards in this Set
- Front
- Back
Neoendemic |
Species that occupies a small area because it has only recently evol ed from a closely related species. |
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Paleoendemic |
Ancient species with a narrow geographical range and no closely related extant species. |
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Allee effect |
Inability of a species social structure to function once a population of that species falls below a certain number or density of individuals. |
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Red list criteria |
Quantitative measures of threats to species based on probability of extinction. |
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Extirpated |
Local extinction of a population. |
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Extant |
Presently alive. Not extinct. |
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Extinction debt |
The inevitable extinction of many species in coming years as the result of current human activities. |
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Island biogeography model |
Formula for the relationship between island size and number of species living on the island. |
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Globalization |
Increasing interconnectedness of the worlds economy |
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Shifting cultivation |
Aka slash and burn. Farming method that involves cutting down trees, burning them, planting crops, then leaving when soil fertility declines. |
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Edge effect |
Altered envirronmental and biological conditions at the edges of fragmented habitats |
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Biomagnification |
Process in which toxins become more concentrated in animals at higher trophic levels. |
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Eutrophication |
Process of degradation in aquatic environment caused by nitrogen and phosphorous pollution and characterized by algal blooms and oxygen depletion. |
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First wave of 6th M.E. |
40,000 AMH out of Africa hunt megafauna. 10,000 development of agriculture. |
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How did agriculture drive extinction? |
Manipulation of wild species (domestication) and habitats for human use. Humans can now exist independent of their ecosystem. Pop size doesnt adhere to ecosystems carrying capacity. |
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Second wave of 6th M.E. |
500 ybp. Rise of globalization. New hunting technology. Affects life on many fronts (oceans, islands, etc.) |
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Third wave of 6th M.E. |
1970 - present. Wide variety of species threatened. Overexploitation rampant. |
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Why do we need to estimate extinction rates? |
Observed extinctions not likely representative of all species. We don't know rates for most organisms. We want to predict/prepare for the future! |
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Uncertainty in extinction rates. |
Wait to officially declare species extinct. Species near extinction may exist at low density, be under the radar. Technically not extinct but not reproducing. |
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List the 5 major factors that make a species vulnerable to extinction. |
Narrow geographical range. Small pop. size/ Low density. Rare habitat/single location. Declining pop. size. Huning/harvesting. |
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3 components of rarity. |
Species have narrow geographical range, small population or low density, and are found only in rare habitats or a single location. |
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Why do declining populations decline more? |
Intactable problems: declining due to threats that are difficult to reverse, like habitat loss. Small pop size: genetic bottlenecking and demographic issues. |
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Intrinsic factors making a species vulnerable to habitat change. |
Species with large home range. Seasonal migration. Species are not effective dispersers. Little genetic variability. Species typically found in pristine environment. Specialized niche requirements. |
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Intrinsic factors making species vulnerable to overexploitation. |
Species that form temporary or permanent aggregations. Have no prior contact with people. Large body size. Close relatives threatened with extinction. |
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5 criteria for IUCN red list evaluation |
Observable reduction in numbers of individuals. Total geographical area occupied. Predicted decline in number of individuals. Number of mature individuals alive. Probability of extinction within a certain number of years/generations. |
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3 main effects of habitat fragmentation. |
Reduced area of patches Increased isolation Edge habitats (effects) |