Across
- 1. __ isolation: form of reproductive isolation in which two populations are separated by geographic barriers such as rivers, mountains, or bodies of water, leading to the formation of two separate subspecies
- 3. (two words)selective breeding of plans and animals to promote the occurrence of desirable traits in offspring
- 5. (two words) a change in allele frequency following a dramatic reduction in the size of a population
- 6. (two words) evolution towards similar characteristics in unrelated species
- 10. (two words) movement of alleles into or out of a population due to the migration of individuals
- 11. an evolutionary process in which one species splits into two or more species
- 13. ___ isolation; form of reproductive isolation in which two populations develop differences in courtship rituals or other behaviors that prevent them from breeding
- 15. __ structures: structures that do not have a common evolutionary origin but are similar in function
- 16. (two words) all the genes, including all the different alleles for each gene, that are present in a population at any given time
- 18. term used to refer to the species that has died out and has no living members
- 19. ___ selection: a type of natural selection in which extreme variations of a trait are selected against
- 22. (two words) an ancestor that two or more species have in common
- 24. trait that helps organisms of a particular species to survive and reproduce in their unique environment
- 27. ___ selection: natural selection in which individuals at one end of the phenotypic range survive more successfully than do other individuals
- 30. (two words) situation in which allele frequencies in population remain the same
- 31. the diversity of life forms in an environment
- 32. __ structure: remnant of a structure that may have had an important function in a species' ancestors, but no clear function in the modern species
Down
- 2. process by which two species evolve in response to changes in each other over time
- 4. (two words) process by which organisms better adapted to their environment tend to survive and produce more offspring
- 7. ___ selection: natural selection in which individuals at the upper and lower ends of the curve have higher fitness that individuals near the middle of the curve
- 8. (two words) structures in different species that are similar because of common ancestry
- 9. __ isolation: form of reproductive isolation in which two or more species reproduce at different times
- 12. change over time
- 14. (two words)history of life as documented by fossils, the remains or imprints of the organisms from earlier periods preserved in sedimentary rock
- 17. ___ isolation: separation of species or population so that they no longer interbreed and evolve into different species
- 20. a proposed explanation in evolutionary biology stating that new species arise from the result of slight modifications (mutations and resulting phenotypic changes) over many generations
- 21. (two words) process by which a single species or a small group of species evolves into several different forms that live in different ways
- 23. (two words) phenomenon by which allele frequencies in a population change as a result of random events
- 25. __ mating: mating among individuals on the basis of their phenotypic similarities or differences, rather than mating on a random basis
- 26. (two words) change in allele frequencies as a result of the migration of a small subgroup of a population
- 28. how well an organism can survive and reproduce in its environment
- 29. ___equilibrium: the theory that new species evolve suddenly over relatively short periods of time (a few hundred to a thousand years)