jepodary

• What was the prevailing idea prior to the time of Lyell and Darwin?

  Earth is a few thousand years old, and species are unchanging
• Name the 4 supports of Darwin’s Theory of Evolution.

  –Direct observation

  –Homology

  –Fossil record

  –Biogeography
• What is the definition of phylogeny and what is the study of it called?

  The evolutionary history of a species or group of related species; systematics
• What is a molecular clock?

  A molecular clock uses constant rates of evolution in some genes to estimate the absolute time of evolutionary change
• What is microevolution and its three main mechanisms?

  A change in allele frequencies in a population over generations, and natural selection, genetic drift, and gene flow.
• What are the three main sources of genetic variation?

  Altering gene number or position

  Rapid reproduction

  Sexual reproduction
• What does the Hardy-Weinberg Principle state?

  Frequencies of alleles and genotypes in a population remain constant from generation to generation
• What are the five conditions for non-evolving populations according to Hardy-Weinberg?

  No mutations

  Random mating

  No natural selection

  Extremely large population size

  No gene flow
• What are the five prezygotic and the three postzygotic reproductive barriers?

  Habitat Isolation

  Temporal Isolation

  Behavioral Isolation

  Mechanical Isolation

  Gametic Isolation

  Reduced Hybrid Viability

  Reduced Hybrid Fertility

  Hybrid Breakdown
• What is the average time needed for speciation to occur?

  6.5 million years
• What is radiometric dating used for?

  Absolute ageing of fossils.
• What is a mass extinction and how many have there been?

  A dramatic increase in the rate of extinction resulting in the loss of large numbers of species; 5 mass extinctions have occurred.
• What caused the Cretaceous Extinction?

  Meteorite impact off the coast of Mexico that disturbed the global climate.
• What are adaptive radiations and what causes them to occur?

  The evolution of many diversely adapted species from a common ancestor.

  Mass extinctions

  The evolution of novel characteristics

  The colonization of new regions