History of biological diversity

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Across
  1. 4. A diagram used in cladistics to show relations among organisms, shaped like a tree branching out. (9 letters)
  2. 8. A model of evolution that proposes species undergo long periods of little change, interrupted by brief periods of rapid change. (20 letters)
  3. 11. The type of speciation that occurs when biological populations of the same species become isolated from each other due to geographic changes. (19 letters)
  4. 12. The type of speciation that occurs when biological populations of the same species become isolated from each other due to geographic changes. (19 letters)
  5. 13. The evolutionary history and relationships of a group of organisms. (9 letters)
  6. 14. event in which a large percentage of all living species become extinct in a relatively short period of time. (14 letters)
  7. 17. The rapid evolution of life that occurred roughly 540 million years ago, resulting in the rise of most major animal phyla. (16 letters)
  8. 19. formation of new and distinct species in the course of evolution. (10 letters)
  9. 20. formation of new and distinct species in the course of evolution. (10 letters)
  10. 21. Structures that have a similar function but did not evolve from a common ancestor, like the wings of a bird and a butterfly. (19 letters)
Down
  1. 1. A broad taxonomic category above the kingdom level, of which there are three. (6 letters)
  2. 2. The diversification of a group of organisms into forms filling different ecological niches, often following a mass extinction. (17 letters)
  3. 3. The scientific study of naming, defining, and classifying groups of biological organisms. (8 letters)
  4. 5. Random changes in allele frequencies within a population, which has a more pronounced effect in smaller populations. (12 letters)
  5. 6. The sharp reduction in a population's size due to environmental events, leading to a loss of genetic diversity. (9 letters)
  6. 7. The preserved remains or traces of ancient organisms. (7 letters)
  7. 9. The mechanism proposed by Darwin where organisms better adapted to their environment tend to survive and produce more offspring. (16 letters)
  8. 10. The process by which different species evolve similar traits because they occupy similar environments. (20 letters)
  9. 15. Features in different species that are similar because of common ancestry. (19 letters)
  10. 16. A diagram that shows evolutionary relationships among a group of organisms based on shared characteristics. (8 letters)
  11. 18. A reproductive barrier that prevents individuals from different species from mating or successfully fertilizing an egg. (11 letters)