Evolution of Life

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Across
  1. 3. Preserved evidence of organisms that once lived on Earth
  2. 5. Australopithecine that is used as evidence of Human Evolution
  3. 7. Fossil that runs through multiple layers of rock
  4. 9. Cause of variation in a species
  5. 10. Preserving environments slow bacterial decay by limiting moisture and _______
  6. 11. Monotremes are _____________ organisms
  7. 12. Preserving environment that produced mummies
  8. 13. In order for a fossil to form, it must decay _________
  9. 14. Example of an indirect fossil
  10. 17. Tree sap
  11. 19. Fossils that aren't the organism itself
  12. 20. Dating technique that gives the actual age of the fossil
  13. 23. Fossils found in a single layer in multiple locations
  14. 25. Organisms that can interbreed and produce fertile offspring are the same _________
  15. 27. _______________: same structure in different species are due to similar environments
  16. 30. Preserving environment that is the coldest
  17. 31. Example of a preserving environment
  18. 32. Fossil that forms when the chemical composition of the original organism is changed
  19. 34. Relative dating technique
  20. 35. Natural selection results in an increase of the trait in the _____________
  21. 36. Radioactive dating uses an isotopes ___________ to date a fossil
Down
  1. 1. Organisms must have _________________ for natural selection to occur
  2. 2. Homologous structures: similarities in anatomy are due to being descended from a _____________________
  3. 4. Fossilised faeces
  4. 6. __________________ anatomy: extent to which the bones of an organism show similarities
  5. 8. When a fossil is subjected to mineral replacement it is ______________
  6. 15. Fossil that shows fine detail
  7. 16. Fossil that is made of the same composition as it was when it died
  8. 18. Selective ______________: is the environmental change required to change the characteristics of an organism
  9. 21. Stay out of my Swamp
  10. 22. A change in the characteristics of a species over many generations resulting in the formation of a new species
  11. 23. Second step in speciation
  12. 24. Fossils are more likely to form when they are not eaten by ________________
  13. 26. Fossils are exposed by _____________
  14. 28. Strata that are lower down are _________
  15. 29. Environments that increase the chance of fossilising soft tissue
  16. 33. Usually required for fossilisation to occur
  17. 34. Natural _____________: process by which an environmental factor acts on a population and results in some organisms having more offspring than others