Download 1. PHYLOGENETICS (6 pts).

Bio 312, Spring 2012 Exam 4
(1)
Name:______KEY____________
Please write your name legibly above on the line and first letter of your last name in the box;
5 points will be deducted if your name is hard to read or the box does not contain the correct letter.
Written answers should be concise and accurate; essay answers typically have short correct answers.
1. PHYLOGENETICS (6 pts).
(a) This semester you read 4 articles, each considered the biology of one or more species.
Draw the phylogenetic tree for the species discussed in these papers:
Ailuropoda melanoleuca
Gambusia affinis
Gambusia hubbsi
Thaumoctopus mimicus
Homo sapiens
(b) As described earlier in the semester, several members of the CSULB biology department
currently study (or used to study) the evolution of organisms they are interested in. Draw the
phylogenetic tree for the species that some of the the ecology/evolution types in the CSULB
biology department study:
Aquatic insects (Underwood)
Cyanobacteria (Dillon)
Deep sea codfish (Wilson)
Fiddler crab (Allen)
Fruit fly (Carter)
Grasses (Malcomber)
Salt cedar (Whitcraft)
Sea urchins (Livingston)
Spionid annelid worm (Pernet)
Western fence lizard (Archie)
White-eared pocket mouse (Huckaby)
Bio 312, Spring 2012 Exam 4
(2)
Name:______KEY____________
2. POPULATION GENETICS. Consider a population of 1200 snakes in which they have either
solid green or striped green color patterns. The color pattern is determined by whether they have the
"G" allele (solid green) or "S" allele (striped); heterozygotes are solid. (2 pts per blank)
Assume that the population is at Hardy-Weinberg equilibrium and that the frequencies of the G and S
alleles are 0.65 and 0.35 respectively.
(a, 2 pts each) How many individuals of each genotype are there? #(GG) = ______507
1200p2 = 507, 1200(2pq)=546, 1200q2=147
(507+546)/1200=0.8775, 147/1200=0.1225
#(GS) = ______546
#(SS) = ______147
(a, 2 pts each) What are the frequencies of the two phenotypes? f(solid) = _____0.8775
1200p2 = 507, 1200(2pq)=546, 1200q2=147
(507+546)/1200=0.8775, 147/1200=0.1225
f(striped) = ___0.1225
(c, 2 pts each) If the allele frequencies were as they
are, but the population has an F value of 0.11, how
many solid and striped individuals do you expect?
(round to the nearest whole individual)
1200p2+2pqF=537.03
1200(2pq)(1-F)=485.94
1200q2+2pqF=177.03
537.03+485.94=1023
# solid = _____1023
# striped = ____177
If suddenly the environment changed and a new predator arrived that hunted the solid pattern, but
ignored the striped pattern we would expect the frequency of the G allele to decline. Consider a
situation in which this happens and 40% of all solid individuals are killed by the predators before
sexual maturity (after then they are safe).
(d, 4 pts) If after a long time the equilibrium frequency of the G allele
is determined to be 20 alleles in a million, what is your best guess
for the mutation rate from the G allele to the S allele?
 = ______8x10-6
(e, 2 pts) Segregating these G alleles lowers the mean
fitness of the population, causing a genetic load.
What is the numerical value of this mutation load?
L = ______1.6x10-5
Bio 312, Spring 2012 Exam 4
(3)
Name:______KEY____________
3. FILL IN THE BLANK (1pt each). Place the best answer choice on the blank provided.
In the third part of the course you read an article about the mimic octopus. The mimic octopus is a
___________ mimic as opposed to the other type of mimic, a _________ mimic.
batesian
mullerian
Species that reproduce season after season are termed ____________, in contrast to species that
iteroparous
mature and reproduce only once which are termed ________________.
semelparous
The phenomenon whereby the same genotype can lead to the development of two very different
phenotypes depending on environmental conditions is termed ___________ ___________ .
phenotypic
plasticity
Sometimes single genetic factors have a disproportionate effect on a phenotype. The analysis
described in class that uses two generations of crosses to discover the locations of these factors
in the genome is called _____________ _____________ ______________ .
quantitative
trait
loci
A group of taxa is termed ___________________ when it includes an ancestral species and all the
monophyletic
species descended from that ancestor.
Shared derived traits are useful for making phylogenetic trees and are termed _______________
synapomorphies
whereas shared ancestral traits, ______________ , cause a type of noise
sympleiosiomorphies
called _______________that makes tree reconstruction more difficult.
homoplasy
Traits that are similar due to shared ancestry are called ____________________ whereas traits that
homologies/homolgous
are similar due to present functional reasons are called ___________________ .
analogies/analogous
Kara's lecture presented a German term used to describe the different realities that different
individuals or species exists within, this term is _________________ .
umwelt
In order for a hypothesis to be scientific it must __________ __________ that are not ad
make
predictions
hoc which allows it to be, in principle, _____________. Hypotheses that do not meet these
falsifiable
criteria may still be true, but they would rely on __________ for support and acceptance.
faith
Bio 312, Spring 2012 Exam 4
(4)
Name:______KEY____________
4. WHY WE DIE. No organism lives forever although in principle, they could. We described
two hypotheses for why senescence occurs and discussed two predictions made by the first
hypothesis that were inconsistent with observed data. We also described a piece of empirical
data that supported the second hypothesis. You will describe these in more detail.
(a, 2 pts) First, weakened, hypothesis for senescence (provide name and describe)
Rate of living hypothesis - side effects of metabolism cause cell damage and
senescence.
(b, 4 pts each) Describe the two predictions this hypothesis made and the
inconsistency in the observed data for each case that weakened this hypothesis.
Faster metabolism causes earlier death - in different mammal orders there was no
relationship between energy use and life span.
Selection to increase life span should be ineffective - fly experiment showed it was effective.
(c, 2 pts) Second hypothesis for senescence (provide name and describe)
Antagonistic pleiotropy - alleles with beneficial effects in youth, but detrimental effects
at old age have been selected for.
(d, 3 pts) Describe the prediction this hypothesis makes and the example provided
in class that illustrates this prediction being borne out.
Predicts these alleles exist - Huntington's disease seems to show this - individuals
seem to have more kids than their non-Huntington siblings, but suffer the disease
when older.
(e, 3 pts) In class we learned the technical term "reproductive value".
Define this term and describe how it relates to the hypotheses above.
This is the expected number of offspring for an individual in the future - this relates to the
antagonsitic pleiotropy situation because selection is weaker on older individuals because
they have lower reproductive value.
Bio 312, Spring 2012 Exam 4
(5)
Name:______KEY____________
5. MULTIPLE CHOICE (2 pts ea)
A severe winter storm kills many chickadees. An investigation comparing the body size of dead birds
withthat of survivors reveals that the dead birds included mainly the largest and smallest members of
the population. This winter storm exemplifies
(A) kin selection
(D) balancing selection
B____ (B) stabilizing selection
(E) disruptive selection
(C) directional selection
Two of the premises that form the basis of Darwin's concept of natural selection are
(A) ecotype and race
(D) geographic and reproductive isolation
B____ (B) heritability and fitness
(E) dominance and recessiveness
(C) uniformatarianism and catastrophism
Which of the following statements is most likely correct concerning the Hardy-Weinberg equilibrium in
natural populations?
(A) It occurs infrequently in small populations from natural communities.
(B) It occurs in founding populations, but not in established ones.
A____ (C) It occurs in populations from late successional communities, but not from early
successional communities.
(D) It occurs on small islands, but not on large islands.
(E) It occurs in species undergoing stabilizing selection, but not in species undergoing
balancing selection.
Under some circumstances a population can split into two or more species without the existence of
geographic barriers. All of the following genetically determined behaviors could provide conditions
leading to speciation EXCEPT
(A) selection of a specific host fruit for completion of the life cycle by a fruit fly
(B) association of courtship with a particular habitat type in a sparrow
D____ (C) choice by a butterfly of the time of the day to breed
(D) release of gametes into the ocean by a marine invertebrate in response to a chemical
in the water
(E) selection of prey types by a wide ranging hawk
Two populations of land snails have been effectively isolated from each other for a long period.
According to the biological species concept, which of the following would demonstrate that the two
populations have become separate species?
(A) The two populations differ in at least five morphological traits.
(B) The two populations behave differently when subjected to the same dose of pesticides.
C____ (C) Sterile hybrids are produced when members of the two populations are experimentally
mated.
(D) DNA nucleotide sequences are different between the two populations.
(E) The two populations have different electrophoretic patterns of proteins.
The theory of punctuated equilibrium argues that
(A) speciation and morphological divergence are weakly associated
(B) selective forces act throughout a species' lifetime
C____ (C) major morphological changes are separated by long periods of morphological stasis
(D) morphological changes occur through selection on polygenic variants
(E) speciation rates are not related to evolutionary rates
Bio 312, Spring 2012 Exam 4
(6)
Name:______KEY____________
Which of the following is a postzygotic isolating mechanism in speciation?
(A) Isolation by hybrid sterility
(D) Behavioral isolation
A____ (B) Isolation by habitat
(E) Geographic isolation
(C) Seasonal isolation
Which of the following is true of a selectively neutral gene that is a mutant at a locus?
(A)Its effects on fitness are different from those of the more frequent allele that leads to a
normal phenotype.
C____ (B) It reaches high frequencies because of the state of balanced polymorphism.
(C) It confers neither reproductive advantage nor disadvantage on the individual.
(D) Its expression is masked by the normal allele.
(E) It improves the fitness of the individual in the heterozygous state.
The phenomenon of genetic drift is most likely to occur in populations that
(A) are large and panmictic
(D) are small and inbred
D____ (B) are undergoing gene flow
(E) have great reproductive potential
(C) are allopatric
If the alleles A and a conform to Hardy-Weinberg expectations, and if the frequency of a is 0.3, which
of the following is the most common genotype is the population?
(A) A
(D) Aa
C____ (B) a
(E) aa
(C) AA
The resemblance of body structure and mode of life of some species of Australian marsupials to
certain species of placental mammals is an example of
(A) convergent evolution
(D) sequential evolution
A____ (B) punctuated equilibrium
(E) polymorphism
(C) genetic drift
Which of the following genotypes would produce the greatest variety of gametes if the alleles assorted
independently?
(A) aaBBCcDd
(D) AABBCCDD
E____ (B) aabbCCDD
(E) AAbbccDd
(C) AaBbCCDd
An important evolutionary benefit of sexual reproduction is that
(A) it provides a mechanism for genetic recombination
(B) it requires a lower level of resource investment than asexual reproduction
A____ (C) the offspring will resemble their parents their parents genetically
(D) the offspring will probably not mate with parents or siblings
(E) the reproductive success rates are less variable than for asexual reproduction
The unit of life in which biological evolution actually occurs is usually considered to be the
(A) adaptive trait of an organism
(D) community
C____ (B) whole organism
(E) ecosystem
(C) population
Bio 312, Spring 2012 Exam 4
(7)
Name:______KEY____________
6. KARA'S SEXUAL SELECTION LECTURE
In her lecture Kara described "run away" and "chase away" sexual selection.
(a, 3 pts) Describe the main point that "run away" and
"chase away" sexual selection have in common.
Both create a cycle in which a male trait gets exaggerated by sexual selection
(b, 3 pts) Clearly describe the difference between "run away" and
"chase away" sexual selection, how do they differ?
In run away the female preference gets stronger and the male trait gets larger to respond to the
overall increase in preference
In chase-away the female preference decreases (female resists) so the traits gets larger to overcome
the resistance.
In her lecture Kara described something called an "operational sex ratio." Describe what this is,
being sure to distinguish between this and the actual sex ratio and how and why they differ (4 pts)
The operational sex ratio is the ratio between the nuber of females able to reproduce at that time and
the number of males, not just the number of females and males.
Bio 312, Spring 2012 Exam 4
(8)
Name:______KEY____________
7. HUMAN EVOLUTION
The human fossil record is poor compared to that of many other organisms, but several features of
our ancestors were unique and therefore very useful for diagnostic purposes.
(a, 2 pts) The fossil of orrorin from almost 6 million years ago is very fragmentary yet a feature
of it illustrates a unique feature of human evolutionary history, which aspect is this?
Orrorin included a femur with a trochanter designed for upright walking.
(b, 2 pts) The fossil of ardipithecus from 4.4 million years ago is also very fragmentary yet a
feature of it illustrates a unique feature of human evolutionary history, which aspect is this?
Ardipithecus was a set of teeth, the shape and nature of
teeth in humans is very different from other species.
More recent human ancestors left more complete fossil records which provide more information about
these species than the earlier species.
(c, 2 pts ea) Homo erectus had a skeleton similar to modern humans and evidence
suggests that these individuals has acquired two technological innovations not used
by other animals, what were these innovations?
(1) Homo erectus fossils were found with stone tools
(2) Homo erectus fossils were found with evidence of controlled fire
(d, 2 pts ea) Homo neanderthalensis fossils showed two signs of advanced cultural
practices not seen in animals. What physical evidence was discussed and what
implications do these suggest.
(1) An individual with a broken and healed femur indicates a level of caring and
support for severely injured individuals.
(2) Flower petals scattered over remains indicate potential religeous practices.
Bio 312, Spring 2012 Exam 4
(9)
Name:______KEY____________
8. HOW WE STUDY EVOLUTION (12 pts) We considered three major methods used to study the
evolutionary process. For each of these three:
- provide the name of the method
- provide at least two examples from class using this technique.
- Provide one weakness to the exclusive use of this method.
Method Name
_________________
Examples
______________________
Weakness
__________________________
Observational
panda thumb, mammal
ear bones, giraffe neck length,
red color effects in humans,
bower birds
Can't separate factors
Hard to observe some things
Variation may be lacking
_________________
______________________
__________________________
Experimental
coral snake color, bird tail
length/mite resistance,
badge size in blackbirds
Not always ethical
Short time periods
Not always practical
_________________
______________________
__________________________
Comparative
primate testes size
Comparing different data tricky
Data not available. hard to get
Stats issues, nonidependance
_________________
______________________
__________________________
9. EVOLUTIONARY FACTORS. (6 pts) Which three traits must a population of individuals have or
possess to undergo sustained directional evolution?
______________________Variation
______________________Heritability
______________________Selection
Bio 312, Spring 2012 Exam 4
( 10 )
Name:______KEY____________
10. MULTIPLE CHOICE (2 pts each)
Consider a mutant allele that causes mosquitos to fly slower and they are therefore less able
to escape predators and the effects of the slowing are seen in heterozygotes, but are even
worse in homozygotes. Which of the following is the best description of this scenario?
(A) The wildtype allele is deleterious, the mutant allele is recessive and advantageous.
(B) The wildtype allele is deleterious, the mutant allele is dominant and advantageous.
D_____ (C) The wildtype allele is advantageous, the mutant allele is recessive and deleterious.
(D) The wildtype allele is advantageous, the mutant allele is codominant and deleterious.
(E) The wildtype allele is advantageous, the mutant allele is dominant and deleterious.
Which of the following is the best definition of a fitness peak?
(A) A region of morphospace in which individuals have higher fitness than other regions.
(B) A region of morphospace in which individuals have lower fitness than other regions.
(C) A region in which individuals experience lower fitness due to geographic factors
A_____ (D) The region between two mountain in which populations have a hard time thriving due to the altitude.
(E) The region in which hybrids do better than pure populations.
If a female prefers a particular trait in males because it indicates an overall level of health and
vigor that allows it to handle living with the trait, which of the following is the best term to
describe the type of female choice process at play?
(A) Direct benefit
C_____(B) Good genes
(C) Handicap principle
(D) Hybridization avoidance
(E) Pre-existing bias
(F) Runaway sexual selection
Behaviors that result in benefits to related individuals would be termed:
(A) Advantageous
E_____(B) Altruistic
(C) Antagonistic
(D) Epistatic
(E) Kin selection
(F) Qualitative
11. GAME THEORY (3 pts each)
Given the following payoff matrix for a Hawk:Dove situation, what would the equilibrium frequency of the Hawk
and Dove strategies be?
HAWK
DOVE
% Hawk = _____60%
HAWK
-20
+60
% Dove = _____40%
DOVE
0
30
Bio 312, Spring 2012 Exam 4
( 11 )
Name:______KEY____________
12. GEOLOGIC TIME PERIODS (1 pt each) Fill in the geologic time period names in the blank
boxes in the table below. Fill in the missing dates on the chart (MYA is Million Years Ago).
Holocene
Quaternary
0.1 MYA
Pleistocene
1.8 MYA
Miocene
Cenozoic
Pliocene
Miocene
Tertiary
Oligocene
Eocene
Paleocene
Phanerozoic
Phanerozoic
Cretaceous
Mesozoic
Jurassic
Triassic
65 MYA
144 MYA
206 MYA
251 MYA
Permian
Carboniferous
Paleozoic
Devonian
Silurian
Ordovician
Cambrian
543 MYA
Proterozoic
2500 MYA
Achaean
3600 MYA
Hadean
4600 MYA