Evolutionary!

4. Study of embryos, used to find similarities between species during development.
7. The theory that natural disasters shaped the earth's landforms and caused extinction.
8. The gradual biological process of change by which descendants begin to greatly differ from their ancestors.
13. A form of evolution between unrelated species, that result in similar characteristics, due to similar environmental conditions.
15. A feature that an organism develops to better survive in its environment.
16. A difference in a physical trait.
18. The complete elimination of an entire species .
19. A preserved trace of an organism from the past.
20. An observable change in the allele frequencies in a population.

1. The measure of survival ability and ability to produce for offspring.
2. A natural mechanism by which a species, or member of that species inherits a beneficial adaptation that allows it to produce more offspring than others.
3. The process in which multiple species evolve in response to the changes in each other.
5. The ability for a trait to be passed down.
6. The total number of genes of every individual in a population
9. Producing more offspring than will likely survive.
10. Structure or organ that are similar structure, but different in purpose.
11. The process by which humans select traits through breeding.
12. A form of evolution between similarly related species, into more different species, due to differing environmental conditions.
14. The idea that geologic processes that shape the earth remain constant over time.
17. The physical movement of particular alleles from one population, to another.