Download Unit 7 Review Guide

Unit 7 Review pt. 1: Evolution- Chapters 22-24
Topics / Concepts:
 evidence for evolution (fossils, biogeography, comparative anatomy, molecular homologies, etc.)
 Darwin and natural selection (plus Darwin’s influences, and Darwin vs. Lamarck)
-examples of natural selection in action
 population genetics
-Hardy-Weinberg equilibrium, equation
 microevolution (and causes)
-genetic drift, gene flow, mutations, nonrandom mating, natural selection
 modes of selection (stabilizing, directional, diversifying, sexual selection)
 speciation
 prezygotic and postzygotic barriers
 allopatric and sympatric speciation modes
 adaptive radiation
 gradualism vs. punctuated equilibrium
 Frequency-dependent selection- the frequency of a polymorphism determines how that trait is selected ex: since both bees &
yellow jackets are black & yellow, this high frequency positively reinforces the selection for this trait since predators avoid it;
ex 2: if there are moths that taste bad and similar colored/patterned moths that taste good, if there are too many good
tasting ones, this causes negative selection for that trait
VOCABULARY:
Chapter 22
Paleontology
Sedimentary rock
Biogeography
Artificial selection
Homologous structures
Darwin vs. Lamarck
Convergent evolution/ Analagous
structures
Chapter 23
Micro- vs. macroevolution
Species
Population
Gene pool
Genetic drift (2 ex’s: Bottleneck
Effect & Founder Effect)
Gene flow
Sexual dimorphism
Hardy-Weinberg equilibrium
Chapter 24
Speciation / definition of species
Pre- and postzygotic barriers
Allopatric vs. sympatric speciation
Adaptive radiation
Gradualism; Punctuated equilibrium
Review Questions:
1) Porcupines use their quills to scare off potential predators/enemies. Explain how this specific trait evolved in
porcupines using:
a) Larmarck’s ideas:
b) Darwin’s ideas:
2) Discuss the main points of the theory that Darwin documented in his publication, “The Origin of Species.”
3) The embryos of mammals and birds both have gill pouches. Which line of evidence for evolution does this fall
into? Describe two other examples from this line of evidence.
4) In a population that is in Hardy-Weinberg equilibrium, 16% of the individuals show the recessive trait. What is
the frequency of the dominant allele in the population? In a population of 2500 individuals, how many would possess
each genotype?
5) In a population that is in Hardy-Weinberg equilibrium, the frequency of the dominant allele is 0.3. In a
population of 15,550 individuals, how many would be heterozygous?
6) Distinguish between genetic drift and gene flow.
7) Identify the type of reproductive barrier illustrated by the following examples and indicate whether they are
pre- or postzygotic barriers.
Type of Barrier
Pre- or Postzygotic
Example
Two species of frogs are mated in the lab and produce viable, but
sterile, offspring.
Two species of sea urchin release their gametes at the same time,
but cross-specific fertilization does not occur.
Two species of orchid have different length nectar tubes and are
pollinated by different species of moths.
Two species of mayflies emerge during different weeks in
springtime.
Two species of salamanders will mate in the lab and produce viable,
fertile offspring, but offspring of these hybrids are sterile.
Two similar species of birds have different mating rituals.
When two species of mice are bred in the lab, embryos usually abort.
Peepers breed in woodland ponds, whereas leopard frogs breed in
swamps.
8) How can prezygotic and/or postzygotic barriers lead to speciation?
9) Is evolution random or goal-oriented? (i.e. is there some ultimate goal or grand plan for evolution?) Explain.
10) Compare the gradualism and punctuated equilibrium theories/models of evolution.
11) What is the evolutionary significance of demonstrating that fly eyes result using a mouse eye gene?
12) Why do extensive adaptive radiations often follow mass extinctions?