Download Organic Evolution

Organic Evolution
This unit includes Chapters 19-26, with a focus on Chapters 20, 21 and 23.
Several handouts will also provide condensed, vital information. The emphasis is
on mechanisms and understanding evolution, not on a recitation of natural
history.
Upon completion of this unit, you will be able to:
 Define the following terms: evolution, natural selection, artificial selection,
biogeography, comparative anatomy, comparative embryology, bioinformatics,
homologous structure, analogous structure, population, population genetics,
modern synthesis, gene pool, microevolution, macroevolution, Hardy-Weinberg
equilibrium, genetic drift, bottleneck effect, founder effect, gene flow, variation,
polymorphic, mutation, balancing selection, heterozygote advantage,
frequency-dependent selection, fitness (in an evolutionary sense), stabilizing
selection, disruptive selection, diversifying selection, directional selection, sexual
selection, adaptation, sexual dimorphism, biological species concept,
morphological species concept, phylogenetic species concept, taxonomy,
systematics, phylogeny, reproductive barrier, prezygotic barrier, postzygotic
barrier, habitat isolation, behavioral isolation, mechanical isolation, gametic
isolation, hybrid inviability, hybrid sterility, hybrid breakdown, speciation,
allopatric speciation, sympatric speciation, polyploidy, adaptive radiation,
gradualism, punctuated equilibrium, exaptation, evolutionary trend, transitional
form, red queen hypothesis, coevolution, phylogram, cladogram, cladistics,
pseudogene, neutral variation, convergent evolution, gene duplication,
homolog, ortholog, paralog sister species, sister clade, systematics, clade
homologous, derived, ancestral, synapomorphies, evolutionary reversal,
homoplasies, parsimony, maximum likelihood, molecular clock, convergent
evolution
 Explain how humans have used artifical selection to create the diverse
domesticated animals and plants we use.
 Differentiate between micro and macroevolution.
 Write the Hardy-Weinberg formulas and explain each term in the equations.
 Use the Hardy-Weinberg formulas to determine allele, genotype and phenotype
frequencies in populations.
 List the 5 assumptions of the Hardy-Weinberg equilibrium.
 Give 5 main mechanisms of microevolution.
 Explain the consequences of violations of the Hardy-Weinberg equilibrium.
 Explain what happens to a population that is in Hardy-Weinberg equilibrium.
 Differentiate between founder effect and bottleneck effect.
 Graph changes in allele frequencies in simulations of small and large
populations, and populations undergoing natural selection.
 Explain how sexual recombination and mutation lead to increased variation.
 Identify the ultimate source of new alleles and new genes.
 Give examples of diversifying (disruptive) selection, directional selection and
stabilizing selection and explain the mechanisms leading to each.
 Describe heterozygote advantage and explain how it could lead to the
maintenance of alleles that are harmful in the homozygous condition.
 Describe fitness in an evolutionary sense.
 Explain why males and females of a species often have widely different
appearances.
 Explain why natural selection does not make “perfect” organisms.
 Describe evidence from biogeography, comparative anatomy, comparative
embryology and bioinformatics that suggest a common ancestry of organisms.
 Compare and contrast the different species concepts.
 Describe ways in which speciation occurs.
 Differentiate among reproductive barriers that reinforce speciation.
 Compare and contrast gradualism and punctuated equilibrium.
 Explain evolutionary novelties come about even though selection only occurs on
species in their current environment.
 Explain why we can see trends in evolution even though evolution is not goal
directed.
 Explain what causes evolutionary radiations.
 Describe examples of coevolution, frequency dependent selection and sexual
selection.
 Describe what is meant by the red queen hypothesis
 Compare and contrast the evolutionary strategies used by males and females.
 Construct phylogenetic trees using prior knowledge and molecular data.
 Explain how gene duplications are important to evolutionary novelty.
 Explain the function of the HOX genes and the implications for evolution.
 Identify homologous structures and genes and differentiate these from
analogous structures and genes.
 Differentiate between derived and ancestral traits.
 Explain how phylogeny and taxonomy are related.
 Describe the last universal common ancestor (LUCA)
 Discuss major events in the history of life on earth as it relates to the universal
phylogenetic tree.
Evolution essays from past AP Exams – note that older essays may be less relevant to the
modern style.
1959:
Discuss how each of the following contributes evidence that evolution has occurred:
a. Paleontology
b. Geographical distribution
c. Biochemical studies
1959:
Each group of organisms has a specific set of adaptations (either in the parent animals
or in the eggs they produce) which helps to insure the survival of sufficient young to
maintain the population. Briefly summarize and compare the structures or other
adaptations bearing on this problem as found in an amphibian, a reptile, a marsupial,
and a placental mammal. What generalizations can be made from these
comparisons?
1960:
Although the arthropods began as aquatic animals, the majority have become
terrestrial.
Discuss the adaptive modifications in the arthropods for terrestrial existence with
reference to locomotion, reproduction, and development, respiration, and water
balance.
1960:
The factors of mutation and isolation are believed to play significant roles in
speciation.
For each of these factors discuss:
a. how it may occur
b. the role it plays in speciation
1963:
Discuss the evolution of both land animals and land plants from aquatic ancestors with
respect to their adaptations for:
a. water conservation
b. support
c. embryo protection
1964:
On the archipelago of the Galapagos Islands, which most geologists believe to be of
volcanic origin without ever having had any land connection with the west coast of
South America, Darwin discovered a group of small finches. These birds have since
been classified into more than a dozen species. These birds have differences, particularly in their adaptations for food-getting. It is believed that all these species are
descendants of a single species which migrated from the mainland. On the mainland
there has never been more than a single species even though the rate of mutations
is thought to be the same in both locations.
Explain how each of the following could have played a role in the development of the
many species of Galapagos finches:
a. polyploidy
b. genetic drift
c. geographic isolation
d. unoccupied ecologic niches
e. Explain why the mainland species has not differentiated into more
than one species.
1966:
In the vertebrates, changes in mechanisms of fertilization and embryonic
development have been of adaptive value. Compare these mechanisms and
indicate their contribution to the evolutionary success of the following animals:
a. fish
b. amphibian
c. bird
d. mammal
1966:
The theory of organic evolution is based on interpretations of observations from diverse
areas. Describe the observations from each of the following areas and explain how
they
support the theory:
a. paleontology
b. comparative anatomy or embryology
c. biochemistry or genetics
1970:
An interbreeding population sometimes gives rise to two populations. Discuss the
possible roles of each of the following factors in the formation of two distinct species.
a. isolation
b. selection
c. mutation
d. genetic drift (Sewall Wright phenomenon)
1972:
Cite evidence from biochemistry, paleontology, and population genetics that has led
biologists to accept the theory of evolution.
1973:
On the basis of reliable sampling studies made during a 5-year period, the following
observations were made about the turtle populations of two lakes, one 300 miles north
of the other. Indicate and discuss factors that might account for this unequal
distribution.
a. Turtles of species A are abundant in the northern lake where turtles of
species B are rare.
b. Turtles of species B are abundant in the southern lake where turtles of
species A are rare.
1974:
Hereditary variations are essential to the evolution of populations.
a. Describe the different types of hereditary variability
b. Explain how this variability can lead to the origin and maintenance of species.
1975:
Most mammals live on land. Describe and discuss the evolutionary adaptations that
make mammals better adapted to life on land than amphibians.
1977:
Two geographically isolated populations usually will diverge over a long period of
time.
a. Describe how the two populations may become different, including factors
that can account for these differences.
b. Discuss factors that may prevent interbreeding if the two populations ever
again occupy the same area.
1978:
Describe the nature of each of the following and discuss the role of natural selection
in each situation:
a. Industrial melanism
b. DDT resistance in insects
c. Sickle cell anemia and malaria
1979:
Charles Darwin's theory of natural selection had a significant influence on the understanding of the evolution of organism. Discuss each of the following:
a. the importance of Darwin's voyage on the H.M.S. Beagle to the development
of his theory;
b. the major points proposed by Darwin in his theory;
c. two major refinements in Darwin's theory that stem from modern findings;
1980:
Discuss the significance of each of the events listed below in the evolution of living
things.
a. Primordial reducing atmosphere
b. Origin of photosynthesis
c. Increase in atmospheric oxygen and the development of the ozone layer
d. Origin of eukaryotes
1981:
Define, discuss, and give an example of how each of the following isolating
mechanisms
contributes to speciation in organisms.
a. Geographical barriers
b. Ecological (including seasonal) isolation
c. Behavioral isolation
d. Polyploidy
1982:
Describe the special relationship between the two terms in each of the following pairs.
a. Convergent evolution of organisms and Australia
b. Blood groups and genetic drift
c. Birds of prey and DDT
1984:
Describe the modern theory of evolution and discuss how it is supported by evidence
from two of the following three areas:
a. Population genetics
b. Molecular biology
c. Comparative anatomy and embryology
1984:
Describe how the following adaptations have increased the evolutionary success of
the
organisms that possess them. Include in your discussion the structure and function
related to each adaptation.
a. C4 metabolism
b. Amniotic egg
c. Four-chambered heart
d. Pollen
1986:
Describe the process of speciation. Include in your discussion the factors that may
contribute to the maintenance of genetic isolation.
1989:
Do the following with reference to the Hardy-Weinberg model.
a. Indicate the conditions under which allele frequencies (p and Q) remain constant
from one generation to the next.
b. Calculate, showing all work, the frequencies of the alleles and frequencies of the
genotypes in a population of 100,000 rabbits of which 25,000 are white and
75,000 are agouti. (In rabbits the white color is due to a recessive allele, w, and agouti
is due to a dominant allele, W.)
c. If the homozygous dominant condition were to become lethal, what would
happen to the allelic and genotypic frequencies in the rabbit population after two
generations?
1992:
Evolution is one of the unifying concepts of modern biology. Explain the mechanisms
that
lead to evolutionary change. Describe how scientists use each of the following
as evidence for evolution:
1) Bacterial resistance to antibiotics
2) Comparative biochemistry
3) The fossil record
1994:
Genetic variation is the raw material for evolution.
a. Explain three cellular and/or molecular mechanisms that introduce variation into
the gene pool of a plant or animal population.
b. Explain the evolutionary mechanisms that can change the composition of the
gene pool.
1994:
Select two of the following three pairs and discuss the evolutionary relationships
between the
two members of each pair you have chosen. In your discussion include structural
adaptations
and their functional significance.
PAIR A:
green algae
vascular plants
PAIR B:
prokaryotes
eukaryotes
PAIR C:
amphibians
reptiles
1995:
The problems of survival of animals on land are very different from those of survival of
animals in an aquatic environment. Describe four problems associated with animal
survival in terrestrial environments but not in aquatic environments. For each problem,
explain an evolutionary solution.