Across
- 3. The diversification of a group of organisms into forms filling different ecological niches
- 6. A process of evolution through which two different existing populations evolve and a distinct species form
- 8. The theory in postulating that the evolution of certain conspicuous physical traits—such as pronounced coloration, increased size, or striking adornments—in animals may grant the possessors of these traits greater success in obtaining mates.
- 9. The hypothesis that evolution proceeds chiefly by the accumulation of gradual changes (in contrast to the punctuationist model).
- 10. A mechanism of evolution characterized by random fluctuations in the frequency of a particular version of a gene
- 11. Occurs when individuals with traits on one side of the mean in their population survive better or reproduce more than those on the other
- 12. The reduction in genomic variability that occurs when a small group of individuals becomes separated from a larger population
Down
- 1. A type of speciation in which biological populations are physically isolated by an extrinsic barrier and evolve
- 2. A type of natural selection in which genetic diversity decreases as the population stabilizes on a particular trait value
- 4. Occurs when a population is greatly reduced in size, limiting the genetic diversity of the species
- 5. The hypothesis that evolutionary development is marked by isolated episodes of rapid speciation between long periods of little or no change
- 7. A pattern of sustained, directional, and incremental evolutionary change over a long period during the history of a species