Across
- 5. Isolation between populations due to barriers related to time, such as differences in mating periods
- 6. Study of the distribution of organisms around the world
- 10. Evolution of one or more closely related species into different species
- 14. Body part that is similar in structure on different organisms but performs different functions
- 15. Proportion of one allele, compared with all the alleles for that trait, in the gene pool
- 16. Remnants of an organ or structure that functioned in an earlier ancestor
- 18. Trace of an organism from the past
- 20. Final stage in speciation, in which members of isolated populations are either no longer able to mate or no longer able to produce viable offspring
- 23. Change in allele frequencies due to chance alone, occurring most commonly in small populations
- 24. Elimination of a species from Earth
- 26. Ability of a trait to be passed from one generation to the next
- 28. All of the individuals of a species that live in the same area
- 29. Process by which humans modify a species by breeding it for certain traits
- 30. Measure of an organism's ability to survive and produce offspring relative to other members of a population
- 31. Body part that is similar in function as a body part of another organism but is structurally different
- 33. Collection of alleles found in all of the individuals of a population
- 37. Mechanism by which individuals that have inherited beneficial adaptations produce more offspring on average than do other individuals
- 38. Process by which one species evolves and gives rise to many descendant species that occupy different ecological niches
- 39. Genetic drift that occurs after a small number of individuals colonize a new area
- 40. Inherited trait that is selected for over time because it allows organisms to better survive in their environment
Down
- 1. Differences in physical traits of an individual from the group to which it belongs
- 2. Physical movement of alleles from one population to another
- 3. Principle that states that changes in landforms result from slow changes over a long period of time
- 4. Theory that states that speciation occurs suddenly and rapidly followed by long periods of little evolutionary change
- 7. Study of fossils or extinct organisms
- 8. Evolution toward similar characteristics in unrelated species
- 9. Process of biological change by which descendants come to differ from their ancestors
- 11. Observable change in the allele frequencies of a population over a few generations
- 12. Theory that states that natural disasters shaped Earth's landforms and caused extinction of some species
- 13. Theory that states that the geologic processes that shape Earth are uniform throughout time
- 17. Pathway of natural selection in which one uncommon phenotype is selected over a more common phenotype
- 19. Group of organisms so similar to one another that they can breed and produce fertile offspring
- 21. Process in which two or more species evolve in response to changes in each other
- 22. Pathway of natural selection in which intermediate phenotypes are selected over phenotypes at both extremes
- 25. Genetic drift that results from an event that drastically reduces the size of a population
- 27. Evolution of two or more species from one ancestral species
- 32. Selection in which certain traits enhance mating success
- 34. Isolation between populations due to physical barriers
- 35. Pathway of natural selection in which two opposite, but equally common, phenotypes are selected over the most common phenotype
- 36. Isolation between populations due to differences in courtship or mating behavior