Download RG 15 - Mechanisms of Evolution

SLUH – Bio 431/AP Bio – Pham
Reading Guide 15
RG 15 – Mechanisms of Evolution*
*Adapted and modified from Robbyn Tuinstra’s work
Section 15.1 – Evolution is both factual and the basis of broader theory
1. Jean-Baptiste Lamarck was one of the first to assert that evolution occurs. What was the
mechanism he proposed?
2. Summarize Darwin’s theory of evolution by natural selection.
3. Explain the statement “Natural selection acts on individuals, but populations evolve.”
Section 15.2 – Mutation, selection, gene flow, genetic drift, and nonrandom mating result in
evolution
4. What is the source of genetic variation? Explain.
5. Define adaptation.
6. Explain how artificial selection shed light on Darwin’s understanding of natural selection.
7. What is the difference(s) between natural selection and adaptation?
8. Why is genetic drift more apparent in small populations?
9. Explain population bottleneck.
10. Explain founder effect.
11. Define fitness. How is fitness determined?
Section 15.3 – Evolution can be measured by changes in the allele frequencies
12. What is the significance of Hardy-Weinberg equilibrium?
13. Summarize the 5 conditions that must be met for a population to be at Hardy-Weinberg
equilibrium.
14. Why is the concept of Hardy-Weinberg equilibrium important even though the assumptions on
which it is based are never completely met in nature?
15. Although the stringent assumptions of Hardy-Weinberg equilibrium are never met completely in real
populations, the genotype frequencies of many populations do not deviate significantly from Hardy–
Weinberg expectations. Explain why.
__________________________________________________________________________________________
Page 1 of 3
SLUH – Bio 431/AP Bio – Pham
Reading Guide 15
16. Summarize the effect of each of the following on allele frequencies in a population.
MUTATIONS
GENE FLOW
GENETIC DRIFT
NON-RANDOM
MATING
NATURAL
SELECTION
Section 15.4 – Selection can be stabilizing, directional, or disruptive
17. Why do phenotypic variations in a population generally resemble a bell-curve?
TYPE OF NATURAL
SELECTION
STABILIZING
SELECTION
DIRECTIONAL
SELECTION
DISRUPTIVE
SELECTION
EFFECT AND EXAMPLE
18. Summarize how each of the following act to maintain genetic variation or contribute to evolutionary
change in populations.
NEUTRAL MUTATIONS
SEXUAL
RECOMBINATION
GENE DUPLICATION
HETEROZYGOTE
ADVANTAGE
Section 15.6 – Recombination, lateral gene transfer, and gene duplication can result in new
features
19. What are some of the potential advantages of lateral gene transfer to the organisms that gain new
genes by this mechanism?
20. Why is gene duplication considered important for long-term evolutionary change?
__________________________________________________________________________________________
Page 2 of 3
SLUH – Bio 431/AP Bio – Pham
Reading Guide 15
21. Why is sexual reproduction so prevalent in nature, despite its having at least three short-term
evolutionary disadvantages?
__________________________________________________________________________________________
Page 3 of 3