Factors of evolution. Laboratory work 3
Answers are for parents and teachers.
1
Describe each of the six factors of evolution in one sentence.
Mutation – a new allele; gene flow – exchange of alleles; drift – random change; wave – change in number; isolation – end of exchange; selection – survival of the adapted.
2
Leaf lengths (cm): 9, 10, 11, 10, 9, 11, 10. Find the mode and the mean. What is the mean? (Number only.)
10
3
Which variation provides material for evolution and why?
Hereditary (mutational and combinative): it passes to offspring and selection sorts these differences.
4
How does gene flow affect differences between populations?
Because alleles are exchanged, populations stay similar and differences decrease.
5
Why are 20–30 specimens, not one, measured in the lab?
With many specimens the pattern of variation (mean and range) appears and chance deviations do not distort the conclusion.