Across
- 4. the physical separation of members of a population
- 6. how reproductively successful an organism is in its environment
- 8. the remains or impression of a prehistoric organism preserved in petrified form or as a mold or cast in rock
- 9. biological evolution that occurs by chance
- 12. the continued existence of organisms which are best adapted to their environment
- 14. when species are reproductively isolated from others due to differences in behavior
- 15. the disappearance of species from Earth
- 19. a physical incompatibility between reproductive organs of two organisms
- 20. a heritable trait that increases an individual’s fitness
- 21. Structures that have no apparent function and appear to be residual parts from a past ancestor
Down
- 1. features of different species that are similar in function but not necessarily in structure and which do not derive from a common ancestral feature
- 2. selection conducted under human direction
- 3. changes in DNA
- 5. new species are generated
- 7. Process by which traits that improve an organism’s chances for survival and reproduction are passed on more frequently to future generations than those that do not
- 10. the process in which two or more populations of an ancestral species accumulate independent genetic changes (mutations) through time
- 11. similar physical features in organisms that share a common ancestor, but the features serve completely different functions
- 13. a sequence of DNA that codes for a particular trait
- 16. when two or more species reproduce at different times
- 17. a form of reproductive isolation, where in habitat preferences of species lower the probability of mating
- 18. change in a population’s gene pool over time