EVOLUTION

12345678910111213141516171819202122
Across
  1. 1. history of life as documented
  2. 5. relative ages of rock strata
  3. 6. older or younger based on their relationships
  4. 9. the similarity of one organism to another
  5. 11. a defense mechanism
  6. 14. complete disappearance of a species
  7. 16. a feature that a species inherited from an ancestor
  8. 18. organisms adjust to new environments
  9. 19. reproductive success
  10. 21. altered remains of a once-living
  11. 22. when two populations are separated by barriers
Down
  1. 2. the inability of a species to breed successfully
  2. 3. present in a reproducing population or species
  3. 4. A group of individuals of the same species
  4. 7. Early stage in the development of species
  5. 8. features of different species that are similar in function
  6. 10. similar physical features in organisms
  7. 12. the identification by humans of desirable traits in plants and animals
  8. 13. the change in frequency of an existing variant
  9. 15. a mechanism of evolution
  10. 17. that deals with the geographical distribution
  11. 20. the change in heritable characteristics