Natural Selection and Variation

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Across
  1. 2. One of Darwin’s four observations states that more offspring are produced than survive to ______.
  2. 4. Gene _____ is the movement of genes from one population to another.
  3. 5. One of Darwin’s four observations stated that characteristics are ______.
  4. 7. Another name for reproductive isolation is ______ speciation.
  5. 8. Struggle for ______.
  6. 10. Reproductive isolation is a form of ______ isolation.
  7. 14. A species is defined as a group of interbreeding populations that are ______ isolated from other groups.
  8. 15. Darwin and Alfred ______ proposed similar theories
  9. 17. Lamarck proposed that ______ characteristics were inherited.
  10. 19. This type of natural selection occurs when selective pressures favour the two extremes of a characteristic.
  11. 21. What animal is used to explain Lamarck’s theory?
  12. 23. The name given to mutations that cause death
  13. 24. This causes variation. It can be harmful, beneficial or neutral.
  14. 27. Genetic ______ brings together new combinations of genes
Down
  1. 1. One of Darwin’s four observations detailed that individuals within a species differ from each other.
  2. 3. One of Darwin’s four observations states that populations are fairly ______ in size.
  3. 6. This type of natural selection occurs when the environment changes.
  4. 9. This type of mutation is the only type that will contribute to large scale evolution (_____ - _____).
  5. 11. This isolation occurs when a population becomes divided by a physical barrier such as water, mountains, desert, etc.
  6. 12. This type of natural selection occurs when the environment does not change.
  7. 13. Another name for geographical isolation is ______ speciation.
  8. 16. Survival of the ______.
  9. 18. Charles ______ first proposed natural selection.
  10. 20. The development of a new species.
  11. 22. ______ Selection.
  12. 25. Variation is the differences in ______ of genes.
  13. 26. This type of mutation will not be passed on to offspring.
  14. 27. Book title – 'On the Origin of ______ by means of natural selection, or the preservation of favoured races in the struggle for life'.