Across
- 4. change in allele frequencies over time
- 8. the physical traits that an organism has
- 10. organisms start new population and this alters allele frequencies
- 12. when organisms enter or leave a population
- 13. natural selection favors the middle phenotype
- 14. natural selection favors one extreme phenotype
- 15. different versions of a gene
- 17. selecting a mate based on a particular trait
- 18. organisms enter a population
- 19. organisms exit a population
- 20. group of organisms in the same place that can interbreed
Down
- 1. the collection of all alleles in a population
- 2. ultimate source of genetic variation
- 3. natural selection favors both extreme phenotypes
- 5. survival of the fittest
- 6. traits that are controlled by several different genes
- 7. the genetic code that an organism has
- 9. evolution of a new species
- 11. natural disaster reduces population size altering allele frequencies
- 16. random changes in allele frequencies in small populations