Biology

1. the formation of new and distinct species in the course of evolution.
4. calculated by dividing the number of times the allele of interest is observed in a population by the total number of copies of all the alleles
10. the reduced genetic diversity which results when a population is descended from a small number of colonizing ancestors.
13. a method of dating rocks and minerals using radioactive isotopes
15. (of an organ or part of the body) degenerate, rudimentary, or atrophied, having become functionless in the course of evolution.
17. pairing at meiosis and having the same structural features and pattern of genes.
18. the process by which a species becomes fitted to its environment
20. any difference between cells, individual organisms, or groups of organisms of any species

2. hide or disguise the presence of (a person, animal, or object)
3. when a population is greatly reduced in size
5. the branch of biology and medicine concerned with the study of embryos and their development.
6. the process through which populations of living organisms adapt and change
7. the variety of life on Earth at all its levels
8. variation in the relative frequency of different genotypes in a small population, owing to the chance disappearance of particular genes as individuals die or do not reproduce.
9. used to arrange geological events, and the rocks they leave behind, in a sequence
11. the ability of an organism to pass on its genetic material to its offspring
12. the hypothesis that evolution proceeds chiefly by the accumulation of gradual changes (in contrast to the punctuationist model)
14. the total genetic diversity found within a population or a species
16. a group of individuals of the same species living and interbreeding within a given area.
19. the close external resemblance of an animal or plant (or part of one) to another animal, plant, or inanimate object.