Across
- 6. Differences in physical traits of an individual from the group to which it belongs
- 8. Theory that states that speciation occurs suddenly and rapidly followed by long periods of little evolutionary change
- 9. Body part that is similar in function as a body part of another organism but is structurally different
- 11. Evolution of two or more species from one ancestral species
- 12. Observable change in the allele frequencies of a population over a few generations
- 15. Evolution of one or more closely related species into different species
- 16. Distribution in a population in which allele frequency is highest near the mean range value and decreases progressively toward each extreme end
- 17. Theory that states that natural disasters shaped Earth's landforms and caused extinction of some species
- 22. Isolation between populations due to barriers related to time, such as differences in mating periods
- 24. Ability of a trait to be passed from one generation to the next
- 25. Theory that states that the geologic processes that shape Earth are uniform throughout time
- 27. Isolation between populations due to differences in courtship or mating behavior
- 29. 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
- 31. Change in allele frequencies due to chance alone, occurring most commonly in small populations
- 32. Process of biological change by which descendants come to differ from their ancestors
- 34. Proportion of one allele, compared with all the alleles for that trait, in the gene pool
- 36. Pathway of natural selection in which two opposite, but equally common, phenotypes are selected over the most common phenotype
- 37. Pathway of natural selection in which one uncommon phenotype is selected over a more common phenotype
- 38. Study of fossils or extinct organisms
- 39. Genetic drift that occurs after a small number of individuals colonize a new area
- 40. Selection in which certain traits enhance mating success
Down
- 1. Principle that states that changes in landforms result from slow changes over a long period of time
- 2. Process in which two or more species evolve in response to changes in each other
- 3. Inherited trait that is selected for over time because it allows organisms to better survive in their environment
- 4. Body part that is similar in structure on different organisms but performs different functions
- 5. Genetic drift that results from an event that drastically reduces the size of a population
- 7. Trace of an organism from the past
- 10. Process by which humans modify a species by breeding it for certain traits
- 11. Group of organisms so similar to one another that they can breed and produce fertile offspring
- 13. Physical movement of alleles from one population to another
- 14. Measure of an organism's ability to survive and produce offspring relative to other members of a population
- 18. Pathway of natural selection in which intermediate phenotypes are selected over phenotypes at both extremes
- 19. All of the individuals of a species that live in the same area
- 20. Evolution toward similar characteristics in unrelated species
- 21. Collection of alleles found in all of the individuals of a population
- 23. Mechanism by which individuals that have inherited beneficial adaptations produce more offspring on average than do other individuals
- 26. Isolation between populations due to physical barriers
- 28. Study of the distribution of organisms around the world
- 30. Elimination of a species from Earth
- 33. Remnants of an organ or structure that functioned in an earlier ancestor
- 35. Process by which one species evolves and gives rise to many descendant species that occupy different ecological niches