Across
- 3. a change in allele frequency following a dramatic reduction in the size of a population
- 4. form of reproductive isolation in which two populations develop differences in courtship rituals or other behaviors that prevent them from breeding
- 5. random change in allele frequency caused by a series of chance occurrences that cause an allele to become more or less common in a population
- 7. principle that states that allele frequencies in a population remain constant unless one or more factors cause those frequencies to change
- 10. when individuals select mates based on heritable traits
- 12. form of natural selection when individuals at one end of a distribution curve have higher fitness than individuals in the middle or at the other end of the curve
- 16. change in allele frequencies as a result of the migration of a small subgroup of a population
- 18. how well an organism can survive and reproduce in its environment
- 20. natural selection in which individuals at the upper and lower ends of the curve have higher fitness than individuals near the middle of the curve
- 24. all the genes, including all the different alleles for each gene, that are present in a population at any one time
- 25. change over time; the process by which modern organisms have descended from ancient organisms
- 26. the study of past and present distribution of organisms
- 27. formation of a new species
- 28. form of reproductive isolation in which two or more species reproduces at different times
- 29. a group of homeotic genes clustered together that determine the head to tail identity of body parts in animals. All Hox genes contain the homeobox DNA sequence.
Down
- 1. structure that is inherited from ancestors but has lost much or all of its original function
- 2. form of natural selection in which individuals near the center of a distribution curve have higher fitness than individuals at either end of the curve
- 6. heritable characteristic that increases an organism's ability to survive and reproduce in an environment
- 8. situation in which allele frequencies in a population remain the same
- 9. structures that are similar in different species of common ancestry
- 11. process by which organisms that are most suited to their environment survive and reproduce most successfully; also called survival of the fittest
- 13. the movement of genes into or out of a population
- 14. the number of times that an allele occurs in a gene pool compared with the number of alleles in that pool for the same gene
- 15. 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
- 17. selective breeding of plants and animals to promote the occurrence of desirable traits in offspring
- 19. a trait controlled by a singular gene
- 21. body parts that share a common function, but not structure
- 22. trait controlled by two or more genes
- 23. preserved remains or traces of ancient organisms