Natural Selection and Variation

2. One of Darwin’s four observations detailed that individuals within a species differ from each other.
4. What animal is used to explain Lamarck’s theory?
5. One of Darwin’s four observations states that populations are fairly ______ in size.
6. Charles ______ first proposed natural selection.
8. Struggle for ______.
9. Darwin and Alfred ______ proposed similar theories
10. Lamarck proposed that ______ characteristics were inherited.
13. This type of natural selection occurs when the environment changes.
15. This isolation occurs when a population becomes divided by a physical barrier such as water, mountains, desert, etc.
16. This causes variation. It can be harmful, beneficial or neutral.
18. This type of natural selection occurs when the environment does not change.
21. Survival of the ______.
22. Genetic ______ brings together new combinations of genes
23. One of Darwin’s four observations states that more offspring are produced than survive to ______.
24. One of Darwin’s four observations stated that characteristics are ______.
26. This type of mutation will not be passed on to offspring.

1. Book title – 'On the Origin of ______ by means of natural selection, or the preservation of favoured races in the struggle for life'.
3. Another name for geographical isolation is ______ speciation.
4. Reproductive isolation is a form of ______ isolation.
7. A species is defined as a group of interbreeding populations that are ______ isolated from other groups.
11. This type of natural selection occurs when selective pressures favour the two extremes of a characteristic.
12. Gene _____ is the movement of genes from one population to another.
14. The name given to mutations that cause death
17. Another name for reproductive isolation is ______ speciation.
18. The development of a new species.
19. This type of mutation is the only type that will contribute to large scale evolution (_____ - _____).
20. Variation is the differences in ______ of genes.
25. ______ Selection.