Across
- 3. The movement of alleles between populations
- 4. Preserved remains or traces of ancient organisms
- 7. An adaptation that helps an organism avoid detection
- 11. A barrier that prevents populations from interbreeding
- 13. A trait that improves survival or reproduction
- 14. An organism that hunts other organisms
- 17. An early stage of development before birth or hatching
- 18. The process by which advantageous traits become more common
- 19. The disappearance of a species
- 20. A source of new genetic variation in populations
- 22. The gradual change in populations over generations
- 23. Structures with the same underlying anatomy but different functions
Down
- 1. Structures with similar functions but different underlying anatomy
- 2. The formation of a new species
- 5. The study of genes and heredity
- 6. The five-digit limb pattern shared by most mammals
- 8. A change in DNA that introduces variation into a population
- 9. An earlier species from which other species evolved
- 10. The study of embryos
- 12. An organism that lives on or in a host and causes harm
- 15. Differences between individuals in a population
- 16. A type of fossil showing features of ancestral and later groups
- 21. A different version of a gene