Natural Selection

4. process by which groups of similar members of a species can no longer interbreed and produce fertile offspring
5. structural adaptation that enables one organism to resemble another
7. hypothesis that argues speciation happens in short rapid bursts of change in between long periods of genetic equilibrium
10. ____ selection selects "for" either extreme of a variation of a trait and against the intermediate forms
11. adaptation that enables anorganims to blend in with their surroundings
14. _____ selection selects "for" the average individual and against other variations of a trait
17. _______ structures of different species indicate a common evolutionary origin
18. pattern of evolution in which distantly related species evolve similar traits due to having similar environmental pressures

1. _______structures are in present day organisms but no longer serve their original pupose
2. _______ generation is the idea that nonliving things can produce life
3. ____isolation is when formerly interbreeding organisms can no longer mate and produce fertile offspring
6. all of the alleles in the genes of a population
8. organisms best adapted to their environment tend to survive and transmit their genetic characteristics
9. breeding organisms with certain traits to get offspring with same traits
10. _____selection selects "for" one extreme of a variation of a trait
12. earliest stage of an organism's development
13. idea that living things come only from other organisms
15. _________ isolation is when a physical barrier prevents 2 groups of a population from interbreeding
16. ___ evolution is the pattern of evolution by which species that were once similar to an ancestral species become more different from each other