NRS 223 Exam 2

• Anthropogenic


  derived from human activities
• DNA Barcoding


  a taxonomic method that uses a short genetic marker in an organism's DNA to identify it as belonging to a particular species
• genetically modified organisms


  An organism whose genetic material has been altered through some genetic engineering technology or technique.
• greenhouse effect


  Natural situation in which heat is retained in Earth's atmosphere by carbon dioxide, methane, water vapor, and other gases, heightened with human activity
• greenhouse gases

  Gases such as carbon dioxide, methane, nitrous oxide, water vapor, and ozone in the atmosphere which are involved in the greenhouse effect
• integrated pest management


  An approach to controlling undesirable plants or animals that has the goal of minimizing harm to the ecosystem and people, while being cost-effective
• International Union for Conservation of Nature (IUCN)


  major international conservation organization
• invasive


  A species that increases in abundance, often because of human changes to the environment, threatens native species through competition, predation, or by changing ecosystem properties or dynamics
• Predator release hypothesis

  Hypothesis that attributes the success of invasive species to the absence of specialized natural predators and parasites in their new range
• zoonosis


  An infectious disease that is transmissible from animals to humans
• 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.
• background extinction rate


  The average rate at which species become extinct over the long term in absence of human impact
• demographic stochasticity/variation


  Random variation in birth, death, and reproductive rates in small populations, sometimes causing further decline in population size
• ecologically extinct


  a species that has been so reduced in numbers that it no longer has a significant ecological impact on the biological community
• effective population size

  number of breeding individuals in a population
• endemic


  Occurring in a place naturally, without the influence of people
• environmental stochasticity


  Random variation in the biological and physical environment. Can increase the risk of extinction in small populations
• extant


  still existing; not exterminated, destroyed, or lost
• extinct


  no longer in existence
• extinct in the wild


  A species no longer found in the wild, but individuals may remain alive in zoos, botanical gardens, or other artificial environments
• locally extinct/extirpated


  A species that no longer exists in a place where it used to occur, but still exists elsewhere.
• globally extinct


  no individuals are presently alive anywhere
• functionally/ecologically extinct


  The state in which a species persists at such reduced numbers that its effects on the other species in its community are negligible
• extinction vortex


  Tendency of small populations to decline toward extinction
• founder effect


  Reduced genetic variability that occurs when a new population is established ("founded") by a small number of individuals
• gene flow


  The movement of genes from one population to another through movement of individuals or gametes
• genetic drift


  Loss of genetic variation and change in allele frequencies that occur by chance in small populations
• genetic rescue


  The practice of intentional introduction of genetic variation into the population of a rare species to keep it from extinction
• inbreeding depression


  Lowered reproduction or production of weak offspring following mating among close relatives or self-fertilization
• Insular Biogeography


  A subdiscipline of biogeography devoted to exploring species diversity on island and in isolated natural communities
• island biogeographic model


  Formula for the relationship between island size and the number of species living on the island; the model can be used to predict the impact of habitat destruction on species extinctions, viewing remaining habitat as an "island" in the "sea" of a degraded ecosystem.
• population bottleneck


  A radical reduction in population size (e.g., following an outbreak of infectious disease), sometimes leading to the loss of genetic variation
• sixth extinction episode

  The present mass extinction event that is just beginning
• species-area relationship


  The number of species found in an area increases with the size of the area (i.e., more species are found on large islands than on small islands)
• Stochasticity


  Random variation; variation happening by chance