Download EEB 245/Spring 2004 C. Simon First Study Guide, second

EEB 245/Spring 2004
C. Simon
First Study Guide, second half of semester. Use this study guide and your problem sets to
study for the final exam. Some of the questions below are similar to those in the problem
sets. The final exam questions will be similar to these but they may be rewritten in a
different form, e.g. fill-in the blank, matching, true/false, etc.
Define Evolution
Define Adaptation
Define Ecology
List several topics that exist at the interface of ecology and evolution.
What are the five most important problems facing the world today and for each list one way
in which a knowledge of evolutionary biology could help ameliorate or prevent it.
Why is the evolution of resistance (e.g. resistance of a bacterium to antibiotics or a pest to
pesticides) known as a “red queen” problem (look in your text)? Why is the same
problem also called “an evolutionary arms race.”
What is favism? What enzyme deficiency causes it? How is it related to Malaria? What
other diseases are also related to Malaria and what do they have in common? Is the
expression of the disease straight forward (explain).
How could a knowledge of evolution help conservation biologists?
Interesting “Evolution vs. Creationism” websites:
www.law.umkc.edu/faculty/projects/ftrials/scopes/scopes.htm
www.talkorigins.org
What Tennessee law was on trial? What did this law state?
What is “Inherit the Wind” and what similarities and differences did it have to the trial?
Are all religions hostile to the concept of evolution? Why or why not?
How many states re-examined the possibility of altering their evolution curricula due to
challenges by creationists in 2003?
According to a 2001 survey, what percent of the American people thought that humans were
created by god during the last 10,000 years?
In the history of evolutionary biological thinking, what were the two major
shifts in worldview?
Compare and contrast the ideas of 1) Linnaeus and Buffon; 2) Cuvier and Lamarck.
Which of the following biologists did not believe in evolution (could be more than one,
Linnaeus, Buffon, Cuvier, Lamarck. Lyell, Darwin, Wallace, Weismann.
Who was the strongest proponent of Catastrophism (review your notes on the differences
between Catastrophism and Uniformitarianism)?
Who was James Cook? Joseph Banks? What role did they play in the early history of
biological exploration?
Darwin was heavily influenced by Lyell, Lamarck, and Malthus. Describe how each of
these people were influential in his thinking.
Was Charles Darwin the first person to suggest a branching diagram of evolution rather
than a ladder of nature?
True or False (if False tell why). Lamarck promoted the idea of the inheritance of acquired
characters. Darwin rejected this idea
Darwin Chronology and Publications
You don’t need to know the dates of Darwin’s publications other than the Origin of Species
but I give them to you for your information. You should be familiar with the main events in
Darwin’s life.
Charles Robert Darwin (1809-1882)
Began his studies at University in medicine but then switched to clerical/natural history
studies. (especially beetles).
1831-1836- Voyaged upon the sailing ship H.M.S. Beagle around the world collecting
specimens and making important biological and geological observations. Visited Brazil,
Argentina, Galapagos, Tahiti, New Zealand, Indian Ocean, South Africa. Darwin was 22-27
year old. Upon returning he married his cousin and became independently wealthy,
allowing him time to think, study, and write. He privately publishes (1835) his “Letters on
Geology” written to his mentor, Professor Henslow,.
Over a 20-year period, Darwin developed his ideas and wrote his most famous book
“Origin of species.”
1837- Ornithologist John Gould points out different species of Galapagos mocking birds.
(Turtles and finch species also varied among islands). Darwin, age 28, starts thinking
seriously about evolution.
1838- A 29-year old Darwin reads Malthus and realizes the importance of a struggle for
existence, natural selection. Unfavorable variants destroyed; favorable variants preserved.
1838- Zoology of the Voyage of the Beagle
1839-Journal of Researches into the Natural History and Geology of the Various Countries
Visited by H.M.S. Beagle.
1839-1842- Questions about the Breeding of Animals
1842-1846- Geology of the Voyage of the Beagle.
1844- A 35-year old Darwin writes an essay on natural selection to be published in the
event of his death.
1849- Manual of Scientific Enquiry (Geology)
1851-54- Living Cirripedia (Barnacle taxonomy- two volumes)
1851-54- Fossil Cirripedia (Barnacle taxonomy- two volumes)
1856- The 47-year old Darwin begins work on his natural selection book.
1858- On the tendency of Species to Form Varieties
1858- At age 49, Darwin receives a completed manuscript from Alfred Russell Wallace
(12-year younger; biogeographer, natural historian, worked in South America and the Malay
Peninsula). The manuscript: “On the tendency of varieties to depart indefinitely from the
original type” independently derived a theory of natural selection, carefully reasoned with
many examples. Futuyma points out that it was neither a sweeping synthesis nor an
explanation of ramifications.
That same year Darwin, wishing to acknowledge Wallace, presents excerpts from his own
work and Wallace’s to the Royal Society.
1859-
At age 50 Darwin publishes the first edition (490 pp), “The origin of species by
means of natural selection or the preservation of favored races in the struggle for
life. The booked evolved through 6 editions.
Followed by a regular succession of books:
18621865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1881
Fertilization of Orchids
Climbing plants
Queries about Expression
Variation under Domestication
Descent of Man
Expression of the Emotions
Insectivorous Plants
Cross and Self Fertilization
Different Forms of Flowers
Flowers and their Unbidden Guests
Movement in Plants
Vegetable Mould and Worms
Following Darwin’s death in 1882, his ideas were championed by August Weismann
(1834-1914). Weismann solved Darwin’s dilemma of blending inheritance when he
proposed in 1893 that somatic (body) cells and germ (gonad: ovary and testes) cells were
independent of somatic cells and that inheritance relied only on gonadal cells. This argued
against the inheritance of acquired characteristics.
*****
What significance did "The Beagle" have for Charles Darwin?
Charles Darwin's contribution to evolutionary thinking was more influential than those
who came before him. Why?
Darwin’s ideas can be grouped into two parts:
A. Evolution itself (this idea was not new)
B. Natural selection. An original idea, independently arrived at by Alfred Russell Wallace,
simply stated that some individuals were more fit, these individuals passed on more traits
than others.
Who was Alfred Russell Wallace and what was his contribution to evolutionary biology?
What did Weismann say about somatic versus gonadal (germ) cells?
Darwin did not know about Mendel's work because ...
What four groups of scientists were working independently at the beginning of the 20th
century?
Recommended readings on the history of evolutionary biology: Provine, W.B. 1971. The
origins of theoretical population genetics. Univ. Chicago Press.
Architects of the Modern Synthesis and their most important works (note most of the works
below are books that summarize their ideas but all of these authors also published many
peer-reviewed scientific papers):
1930- R.A. Fisher, The Genetical Theory of Natural Selection
1931 &32- Sewall Wright- A series of seminal scientific papers on natural selection,
random changes, and migration. (and many more papers after these).
1932- J.B.S. Haldane. The Causes of Evolution.
1937. Th. Dobzhansky. Genetics and the Origin of Species
1942. Ernst Mayr. Systematics and the Origin of Species
1944. Julian Huxley. Evolution: The Modern Synthesis.
1944. G.G. Simpson. Tempo and Mode in Evolution (revised 1953 as “The Major
Features of Evolution”)
1947 (1959 translation). B. Rensch. Evolution Above the Species Level.
1950. G.L. Stebbins. Variation and Evolution in Plants.
1941-1946- Formation of the Society for the Study of Evolution
1952- Formation of the Society of Systematic Biologists
What are the major tenants of the modern synthesis?
Know the major events of the decades since the synthesis:
1953- Watson, Crick and Franklin worked out the structure of DNA. A deeper
understanding of the nature of mutation and inheritance followed. Enhanced by DNA
sequencing in the 1970’s and 80’s.
1960’s- The Debate on the relative amount of variation in natural populations came to a
close.
1970’s- Debate on the relative importance of selection versus drift.
1970’s, 80’s, 90’s, and 00’s- Great improvements in the methods of constructing
evolutionary trees using computers (and great advances in computing speed).
1990’s- Growing recognition of the importance of understanding evolutionary relationships
as a framework against which all biology can be interpreted: physiology, cell biology,
behavior, ecology (comparative method), and medicine,
1990’s, 00’s. Greater understanding of the importance of development to phenotypic
change.
What two important points are made by the Hardy-Weinberg theorem?
If a population is perturbed by natural selection or migration and then that perturbation
is removed, how long will it take the population to return to equilibrium?
What are the assumptions of the Hardy Weinberg equilibrium?
Why do we care about the Hardy Weinberg equilibrium?
Why do we care about violations of the Hardy-Weinberg assumptions?
Why do we care about genetic variability?
How is genetic variability maintained in natural populations (there are many ways)?
When was protein electrophoresis introduced into population biology and by whom?
What is protein electrophoresis and how is it able to detect mutations? What mutations
does it miss?
What did Lewontin and Hubby demonstrate? How did their results change earlier views?
If the frequency of the common allele in a population was .7 and there were only two alleles
at that locus, what would be the expected proportions of each genotype in the next
generation, assuming that the population was in Hardy-Weinberg equilibrium?
List four factors that can cause a heterozygote deficiency in a natural population. Be able
to explain how the heterozygote deficiency is created and how a population biologist
would set about testing for each of these phenomena.
What are two ways to detect natural selection in the field? Give examples.
With respect to testing for natural selection on allozyme frequencies, what is meant by
the phrase, "correlation does not equal causation?"
Why does migration sometimes not equal gene flow?
Discuss the statement, "without genetic variation, there can be no evolution."
Define polymorphic and give three examples of polymorphic traits in nature.
Fill in the blank: Early geneticists working with visible mutants believed that variation
in natural populations was __________?
Reread the section in your text titled “Coalescence” (p298-299) and answer the following
questions: 1) Can you apply exactly the same model of descent to individual genes
within a sexually reproducing population as you can to asexual organisms? 2) Why does
the average degree of relationship of individuals increase with the passage of time? 3)
True or False: If we look backward in time, all gene copies in a populations ultimately are
descended from a single ancestral gene copy. 4) Explain your answer to number 3. 5)
How does population size effect coalescence? 6) Know that the average time back to
common ancestry (coalescence) of a random pair of gene copies in the population is 2N
generations, where N = population size.
Know the five conclusions about genetic drift at the end of page 299.
Define: inbreeding; genetic drift; inbreeding coefficient, random walk, fixation.
How are inbreeding and genetic drift similar?
How are they different?
Can inbreeding occur in large populations? Can drift occur in large populations? Explain
both.
How significant would be the effect of each in a large population?
What is "inbreeding depression" and what causes it?
Why did Lande (1988) argue that inbreeding might be irrelevant in nature?
What did the Finnish butterflies (Glanville Fritillary) illustrate?
Is inbreeding guaranteed to purge most lethal alleles from a population? What does
experimental evidence from botanical studies suggest?
How did Alan Templeton save the Speaks gazelle?
What is purging and why might it be dangerous?
Fill in the blank: In a finite population inbreeding causes the proportion of heterozygotes
in the population to decline because _____________.
True or False: Genetic drift results in lower heterozygosity simply because one allele is
rare.
Define effective population size. Why is the effective population size often much lower
than the actual population size? On the bottom of page 303, your text discusses four
reasons that the effective population size is different from the actual population size.
What are they? Briefly explain each.
You are a conservation biologist who is asked to assess the chances for survival of a
wide spread, formerly common, species that exists presently only as a series of small
isolated populations. If these populations have been small and isolated for some time,
would you expect the level of genetic variability in each population to be high or low?
Would you expect the level of genetic variation in the total species to be high or low? If
you were told that most of the current habitat of this species must be sacrificed to make
way for "progress," what would you recommend as the best strategy to try to preserve the
species?
Define: Founder effect.
How many colonists do you need to preserve 50% of the variability in the original source
population? How many colonists do you need to preserve 75%?
How will a short population bottle neck affect heterozygosity?
How will an extended bottle neck affect heterozygosity?
How will a short bottle neck affect the number of alleles in a population?
How variable are Northern elephant seals? Why? How was genetic variability measured
in this species?
Is mutation alone a strong force in evolution?
Diagram each of the following models of gene flow: a) "continent-island", "island",
"stepping-stone", and "isolation-by-distance."
True or false: Even a low amount of gene flow greatly reduces the divergence among
populations.
True or false: the tendency of genetic drift to augment the total genetic diversity of a
species by fixing different alleles in different populations can be counteracted by gene
flow.
Monarch butterflies and winged versus wingless water strider species have been used to
demonstrate what?
How does Godfrey Hewitt explain his many examples of "Northern purity,
Southern richness"?
True or false: If natural selection favors different genotypes in different populations, the
gene frequency in each will arrive at an equilibrium determined by the relative strength of
selection and gene flow.
What is the neutral theory of molecular evolution?
True or False: If organisms were perfectly adapted to their environment then variation
would make individuals less adapted and less able to compete.
Distinguish between balancing, directional, disruptive, and frequency dependent
selection. Give examples of each.
Will directional selection alone help to maintain variation in natural populations?
Explain how El Nino was an important opportunity for Galapagos finch researchers Peter
and Rosemary Grant.
What is competitive character displacement and what experiment did Dolph Schluter
perform to demonstrate this?
Explain how sexual selection works in opposition to another form of natural selection in
John Endler's Trinidad guppies.
Why were Stud and Dud Hawaiian Drosophila not a good example of Fisher's runaway
sexual selection?
What are the five classes of explanations for the maintenance of genetic variation in
natural populations?
Define genetic "hitchhiking", "genetic load".
Explain how selection and drift work in concert in Sewall Wright's shifting balance theory
of evolution.
Fill in the blank: Spatial and temporal environmental variation
can help to maintain ___________________________________.
Define ecotype. How could ecotypic variation be distinguished from phenotypic
plasticity?
What two examples of extremely strong natural selection did we discuss? Explain how
selection and mutation result in survival.
Define: subspecies, parapatric, allopatric, step cline, gradual cline. Give examples of each.
There is a cline in cyanide content with latitude in Europe because of two opposing
selection pressures. Explain.
We looked at many variants of directional selection. For each of the following examples we
discussed, know the presumed trait under selection, the selective agent, and the result of
selection: peppered moth, Darwin’s finches, Laysan finches, sticklebacks, Trinidad guppies,
American eels, swallowtail butterflies,
Define multiple niche polymorphism, fluctuating selection, frequency dependent selection,
balancing selection, give an example of each.
True or false: an allele at 40% frequency in a population will increase faster than one at
10% frequency even if each allele has exactly the same selective advantage.
Why are rare deleterious alleles difficult to eliminate by natural selection?
Finish this sentence: deleterious dominant alleles will be eliminated quickly from a
population unless _________________________________________________.
What evidence led Lenski to believe that identical E. coli clones had evolved to be different
even though all were able to metabolize glucose equally well?
Discuss how diversifying selection relates to Wright’s shifting balance theory and adaptive
landscapes. How could diversifying selection lead to speciation.
Why is the ADH locus in Drosophila a particularly compelling example of selection
correlated with an environmental trait?
Do all characters vary concordantly (in parallel) with geography? Do they all vary with
geography? Explain.
List three reasons for clines.
Explain the evidence compiled by Lewontin (1972) and Nei and Roychoudhury (1972) that
suggested that race was an artificial concept.
Define ring species and explain what they illustrate about geographic variation, gene flow,
and genetic variation?
List four possible outcomes of secondary contact:
What four factors determine the success of mating?
Why might the term "reproductive isolation mechanism" be misleading?
Give two example of pre-mating factors that reduce gene flow in each of the following
categories: spatial isolation, temporal isolation, behavioral isolation.
There are a wide variety of behaviors that limit gene flow among species by serving as
specific mate recognition systems: some are visual, some aural (sound), and some
chemical. List three types of visual communication. Give examples of three major animal
taxa we discussed that use aural communication.
Insects communicate using scents termed ____________________________.
True or False. If false tell why. All insects communication sounds are carried by
airwaves.
True or False. If False tell why. All insects communication sounds are detectable by the
human ear.
Define: aggressive mimicry.
How do chemical scents in bee-orchids create a species-specific pollination system (inhibit
outcrossing)?
What are three possible explanations for species specific differences in insect genitalia?
What are the four stages at which egg and sperm union (zygote formation) can fail?
True or False? The more distantly related two species, the less likely they are to produce
viable hybrid offspring. What exception to this rule did we discuss?
Lee and Vacquier (1992) sequenced the sperm binding protein in seven species of abalone.
After comparing the DNA sequences among all species they found more differences
among species at second positions in the active sites of proteins than at third positions?
What does this result imply?
Is it usual to find more second than third position changes when comparing proteins of
closely related species? Why or why not?
Not all factors that operate to reduce gene flow between species occur pre-zygotically.
Give two examples of post-zygotic interspecific reproductive barriers.
What problem does polyploidy circumvent to allow hybridization between species?
Define: semispecies.
Who first proposed the idea of "reinforcement" of reproductive isolating characters upon
secondary contact of formerly isolated populations? Who suggested that reinforcement
might complete speciation?
Define hybrid zone and tell why they are of interest to evolutionary biologists.
The width of a hybrid zone is determined by a balance between ______________ and
selection against __________________.
Define introgression:
List four possible fates of hybrid zones:
In each of the following examples from Futuyma, what is the specific character involved in
reproductive character displacement? Australian hylid frogs? Semispecies of Drosophila
paulistorum? Damselflies of the genus Calopteryx? Phlox flowers?
In periodical cicadas, what trait is involved in reproductive character displacement?
How do 1) gene flow, and 2) recombination work against character displacement in a
hybrid zone?
Early computer models of character displacement predicted that upon secondary contact
two populations would fuse rather than developing greater differences due to character
displacement. New models predict character displacement. How do the new models differ
from the old?
What are Dan Howard’s six criteria for demonstrating that reinforcement has occurred?
What are the problems facing the morphological species concept?
How does the phenetic species concept differ from the morphological species concept and
why is the phenetic species concept very difficult to use?
What is the biological species concept?
What are the criticisms of the biological species concept?
What is the evolutionary species concept? What are its advantages and disadvantages?
How does the cohesion species concept differ from the biological species concept? Be
specific.
How does the phylogenetic species concept differ from the evolutionary species concept?
In practice what is the most common species concept to be applied in a large biodiversity
study?
In a detailed study of a specific group of organisms, the most common and useful
species concept to apply is the phylogenetic species concept. This is done via a cladistic
analysis of morphological and/or molecular data. Why would the biological species
concept be impractical in this case?
Remember that: Although in practice the biological and cohesion species concepts are
not easily used, they are useful in theory for understanding the biological basis for
speciation.
Spatial speciation mechanisms can be divided into what three categories?
In allopatric speciation, how does the dumbbell model differ from the peripheral isolates
model?
How does the founder effect work to encourage speciation?
The four species of the black-throated warbler complex are thought to have speciated
via _______________________ due to a barrier caused by______________.
Define ring species. What concept does it illustrate? Give two examples.
What conditions are necessary for parapatric speciation to occur?
Explain this statement: In nature it is difficult to distinguish between primary and
secondary contact.
Give a possible example of parapatric speciation.
Define sympatric speciation. What conditions does it require?
Define host-race speciation and give an example.
How did gradual allochronic change evolve in true fruit flies of the genus Rhagoletis?
Explain the role of life-cycle switching and predator satiation in periodical cicada speciation.
In studies of periodical cicada speciation, the identification of a female wing-flick signal was
important for what reason?
What did Rick Harrison discover concerning the possible allochronic speciation of
Gryllus veletis and G. pennsylvanicus?
Why do chromosomal mutations reduce fertility of the individuals carrying them?
Why is chromosomal speciation (other than polyploidy) expected only in organisms like
gophers, naked mole rats and wingless grasshoppers? i.e. what do these species have in
common and how does it facilitate chromosomal speciation?
The tree frog Hyla versicolor is believed to have evolved from Hyla chrysoscelis by what
mechanism?
What is very unusual about the species H. versicolor and how do the “species as lineages”
and “species as a reproductive community” speciation concepts apply to this case?
In chromosomal speciation involving non-polyploid hybrids, what process gradually
increases the fitness of hybrid offspring so that a fertile hybrid species can eventually form?
How did Loren Rieseburg's experiments with sunflowers demonstrate that the phenomenon
alluded to the in the questions above was specific and occurred repeatedly by different
pathways?
In addition to hybrid sunflowers we discussed an example in animals where hybrid species
may be forming. This example was:
Coyne and Orr’s (1989) study of mating in Drosophila demonstrated 4 things. What are
these?
The fact that prezygotic isolation evolves faster than postzygotic isolation in sympatry but
not in allopatry is evidence for what phenomenon that we discussed earlier?
Define “species radiation.” Relate this concept to “founder events” discussed earlier.
Define endemic.
Know that in Hawaii there are more than 400 species in the genus Drosophila more than all
the rest of the world’s species of this genus. In the Hawaiian silversword radiation there are
more than 20 species (in two genera) which differ significantly in morphology and habit but
can all still interbreed. There are more than 23 species of endemic honeycreepers (plus a
similar number of extinct honeycreepers) and all are descended from a common finch
ancestor.
Know that in Hawaii there are no native amphibians, no native terrestrial reptiles, and no
native land mammals other than bats.
True or False. If false tell why. The native flora and fauna of Hawaii is a random sample of
the species from the mainland and island areas closest to the island chain.
Adaptive shifts commonly accompany adaptive radiations; define adaptive shift. Give two
examples of adaptive radiation