Across
- 4. Explains origin of mitochondria and chloroplasts
- 6. Favors both extreme traits
- 10. Similar structures from common ancestry
- 12. Ship Darwin traveled on
- 13. dating Comparing rock layers by age
- 14. First vertebrates on land
- 15. Two species evolve together
- 16. Formation of a new species
- 17. Cells with a nucleus
- 21. Process by which living things change over time
- 22. Bird adaptation for insulation and flight
- 24. Traits that improve survival
- 25. Vertebrates with amniotic eggs
- 30. Large-scale evolutionary change
- 31. Uses radioactive isotopes to determine age
- 32. Descendants of theropod dinosaurs
- 33. Organelles that produce energy
- 34. Organelles used for photosynthesis
- 36. Movement of alleles between populations
- 38. Early environment where organic molecules formed
- 43. Leftover structures with little function
- 44. Physical separation of populations
- 45. Preserved remains of ancient organisms
- 46. First vertebrates
Down
- 1. No evolution occurs if frequencies stay constant
- 2. Survival of the best adapted
- 3. Unrelated species develop similar traits
- 5. Process from algae to flowering plants
- 7. Plant reproductive structure
- 8. Study of allele frequencies
- 9. Plant tissue that transports water
- 11. Animals with backbones
- 18. Same function but different origin
- 19. Change in DNA creating new traits
- 20. Differences among individuals in a population
- 23. Protects plant embryo
- 26. Geologist who supported gradual Earth changes
- 27. Best adapted individuals are more likely to do this
- 28. Random change in allele frequencies
- 29. First molecules needed for life
- 35. Cells without a nucleus
- 37. Scientist who proposed natural selection
- 39. Substance mammals produce for young
- 40. Earliest mammal ancestors
- 41. Islands where Darwin studied finches
- 42. Study of species distribution