EVOLUTION

2. are the preserved remains or traces of animals, plants, and other organisms from the past.
4. is a theory that suggests that meteorites or comets caused dinosaurs to become extinct in the Cretaceous period
8. it is a dating that estimates fossil age using rock layers
12. is a selection that is the identification by humans of desirable trait in plants and animals
13. a reproductive barrier that prevents development of fertile offspring
14. the study of past life
15. were the first plants to evolve seeds and produce pollen
17. small evolutionary changes that accumulate in a population
18. according to him all changes in nature are gradual
19. a reproductive barrier that prevents fertilization
20. is slow and steady speciation

1. are for obtaining water and minerals, while physically anchoring the plant in the soil
3. a speciation that occurs in a shared habitat
5. who proposed the theory of biological evolution by natural selection
6. marks the end of the line
7. slower and results from large-scale changes
9. proposed the first scientifically testable evolutionary theory
10. is the science of describing, naming, and classifying species
11. the change in the characteristics of a species over several generations
16. is a structure that can develop differently over time