Biology 106 Lab Section ________________________________
Fall 1999 T.A. Name: ________________________________
SS # _____________________________________
(30 points) TRUE or FALSE. Fill in the blank with the entire word. (2 points each)
1. FALSE Gene flow is a concept best described as "an exchange between 2 species".
2. FALSE Cattle breeders have improved the quality of meat over the years by stabilizing selection.
3. TRUE "Ontogeny recapitulates phylogeny" infers that we observe hints of our evolutionary past through our embryonic development.
4. TRUE Evolution occurs within demes or locally breeding populations.
5. FALSE Cryptic coloration allows an individual to advertise that it tastes bad.
6. TRUE OR FALSE Heterochrony describes a change in rate of development.
7. TRUE The changing facial features of a maturing child are an example of allometric growth in humans.
8. TRUE Adaptive radiation is an example of divergent evolution.
9. TRUE Sexual selection helps us to understand how conspicuous characters/traits can evolve.
10. FALSE All traits exhibited by a species are adaptive.
11. TRUE The notation "genotype by environment interaction" is another way to describe an adaptation.
12. FALSE Sea lions commonly exhibit a polyandrous mating system.
13. FALSE Mammalian forelimbs are an example of analogous structures.
14. TRUE Organisms on islands most closely resemble relatives on the closest continent.
15. FALSE Lichens are a classic example of a mutualism since the fungus provides the food and the algae or cyanobacteria provide the "house" or structure .
(30 points) Multiple Choice. Circle the answer that best fits the question. (3 points each)
1) In a large, sexually reproducing population, the frequency of an allele changes from 60% to 20%. From this change one can most logically assume:
A) that the allele is linked to a detrimental allele.
B) that the allele mutates readily.
C) that the allele reduces fitness ANSWER
D) that random processes have changed allelic frequencies.
E) that there is no sexual selection.
2) Which of the following is consistent with the punctuated equilibrium interpretation of speciation?
A) Evolution proceeds at a slow, steady pace.
B) Long periods of minor change are interrupted by short bursts of significant change. ANSWER
C) Rapid speciation is caused by population explosions.
D) There is an equilibrium between living and extinct species.
E) Large populations evolve more quickly than small ones.
3) If two species are able to interbreed but produce sterile hybrids, their species integrity is maintained by :
A) gametic isolation
B) a prezygotic barrier
C) hybrid inviability
D) a postzygotic barrier ANSWER
4) In a population with 2 alleles, A and a, the frequency of a is 0.6. What would be the frequency of heterozygotes if the population is in Hardy-Weinberg Equilibrium?
A) 0.48 ANSWER
5) In the yucca moth and yucca plant example which of the following is true?
A) this is an example of coevolved mutualism.
B) each time a moth lands on a flower the female deposits 1-5 eggs.
C) the female has specialized mouth parts to collect the pollen to transfer to other individuals in the population.
D) the yucca plant has an selective abortion mechanism that stops the development of fruit with too few developing seeds.
E) all of the above. ANSWER
6) R. A. Fisher's Runaway Trait Model is best described as:
A) females are non-discriminating and this leads to drift playing a larger role in the population.
B) the presence of conspicuous traits in the male as well as females preferring males that possess these exaggerated secondary sexual traits, only halted by natural selection. ANSWER
C) if males can survive with exaggerated secondary traits then those individuals must be exceptionally fit.
D female choice coupled with male-male competition.
E) all of the above
7) Which of the following terms best describes the "playfulness of many adult dogs".
C) paedomorphosis ANSWER
8) In the widow bird example from class what did the researchers learn from artificially manipulating tail length?
A) longer tailed individuals successfully copulated more frequently than short tailed males
B) females preferred to mate with longer tailed males
C) tail length did not influence the ability to defend a territory
D) natural selection doe s not appear to be hindering the exaggerated tail lengths currently observed in the population
E) all of the above ANSWER
9) A biologist studied a population of squirrels for 15 years. Over that time, the population was never fewer than 30 squirrels and never more than 45. Her data showed that over-half of the squirrels born did not survive to reproduce, because of competition for food and predation. Suddenly, the population increased to 80 individuals. In a single generation , 90% of the squirrels that were born lived to reproduce. What inferences might you make about this population?
A) The amount of food probably increased.
B) The number of predators probably decreased.
C) The young squirrels in the next generation will show greater levels of variation than in the previous generations because squirrels that would not have survived in the past are now surviving.
D) Both B and C are reasonable inferences
E) All of the above are reasonable inferences. ANSWER
10) The assumptions of Hardy-Weinberg equilibrium include which of the following?
A) No selection
B) No migration
C) No mutation
D) Disassortative mating
E) Random mating
F) Large population size
G) A, B, C. D, F
H) A, B, C, E, F ANSWER
(20 points) DEFINE (3 points) and EXPLAIN AN EXAMPLE (1 point) for each term.
EVOLUTIONARY CHANGES OVER LONG TIME SPANS INVOLVING MANY TRAITS AND LARGE GENETIC CHANGES. THE DERIVATION OF A NEW GROUP ABOVE THE SPECIES LEVEL.
EX., ANY LINE OF EVIDENCE EXPLAINED, THAT I HAVE GONE OVER IN CLASS, BIOGEOGRAPHY, TAXONOMY, FOSSIL RECORD, HOMOLOGOUS STRUCTURES, DEVELOPMENT, VESTIGIAL STRUCTURES, MOLECULAR RECORD, CONVERGENT EVOLUTION,
2) Allopatric Speciation:
SPECIATION OWING TO GEOGRAPHICAL ISOLATION OVER A LONG PERIOD OF TIME WHICH LEADS TO DIVERGENCE AMONG POPULATIONS
EVOLUTION OF REPROD. ISOLATION AFTER POPULATIONS HAVE BECOME GEOGRAPHICALLY ISOLATED.
FOR. EX., POPULATIONS ON 2 SIDES OF A NEWLY FORMED MT. RANGE- ANY LOGICAL SCENARIO
CLOSE ASSOCIATION OF 2 OR MORE DISSIMILAR ORGANISMS WITHOUT ANY IMPLIED VALUE JUDGMENTS.
EX'S, PARASITISM, COMMENSALISM, MUTUALISM OR ANY SPECIFIC ONE MENTIONED IN BOOK OR CLASS
4) Bateman's Rule:
DROSOPHILA WORK BY BATEMAN 1948
MALES LIMITED BY ACCESS TO MATES (FEMALES)
FEMALES LIMITED BY RESOURCES SINCE A SINGLE COPULATION EVENT CAN PROVIDE A FEMALE ALL OF THE SPERM SHE NEEDS TO FERTILIZE HER EGGS SINCE SHE MUST INVEST IN PROVISIONING FOR THE YOUNG.
THEY COULD ALSO DRAW A FIGURE TO DEMONSTRATE THIS. ANISOGAMY
5) Inclusive Fitness:
AN INDIV. CONTRIBUTION AS WELL AS ITS CLOSEST RELATIVES (SIBS) SINCE AS RELATED TO FULL SIBS AS TO PARENTS. THE NUMBER OF PROGENY FROM ONESELF AND CLOSE RELATIVES THAT SUCCESSFULLY CONTRIBUTE GENES TO THE NEXT GENERATION. THEY MAY ALSO USE AN ALTRUISM EXAMPLE TO EXPLAIN THE POINT.
Short Answer In the space provided, supply a concise answer to the following questions.
(20 points total)
1) What is the main difference between Batesian and Mullerian mimicry? Provide a clear example of each. (4 points)
BATESIAN - MODEL TASTES BAD AND THE MIMIC DOES NOT (1 POINT)
MULLERIAN - BOTH ARE DISTASTEFUL (1 POINT)
1 POINT FOR EACH EXAMPLE
NOT. NECESSARY: FREQ DEP SELECTION IN ACTION, MIMIC>MODEL IT WILL NOT WORK.
2) Compare and contrast Post Zygotic and Prezygotic Isolating Mechanisms with regards to any "costs" associated with each while also providing a clear example of each. (4 points)
1 POINT FOR AN ACCURATE COMPARISON OF THE COSTS
1 POINT FOR KNOWLEDGE OF WHY POSTZYGOTIC MECH'S WASTE MORE GAMETES THAN PREZYGOTIC MECH'S OR ANOTHER ACCURATE COMPARISON
1 POINT EACH FOR AN EXAMPLE OF PREZYGOTIC AND POSTZYGOTIC MECH.
POSTZYGOTIC- WASTES GAMETES, (THOUGHT ACTS ON INITIAL CONTACT, NOT NEC.)
PREZYGOTIC DOES NOT WASTE GAMETES, THOUGHT TO ACT ON SECONDARY CONTACT (NOT NEC.) , AND SPECIES MAY HAVE ALREADY DIVERGED.
POSTZYGOTIC : REDUCED HYBRID VIABILITY
REDUCED HYBRID FERTILITY
REDUCED HYBRID VIGOR
PREZYGOTIC : ECOLOGICAL ~ HABITAT
IT IS FINE FOR STUDENTS TO DESCRIBE A MORE DETAILED ILLUSTRATIVE EX.
3) In 2468, 2 male space colonists and 3 females space colonists settle on a uninhabited Earthlike planet in the Andromeda galaxy. The colonists and their offspring randomly mate for many generations. All 5 of the original colonists had free ear lobes, and two are heterozygous for that trait. The allele for free ear lobes is dominant to the allele for attached ear lobes. (6 points total)
a) If one assumes that Hardy-Weinberg equilibrium applies to the original population of colonists on this planet, about how many people will have attached earlobes when the planet 's population reaches 10,000 individuals? (3 points)
E = FREE; e = attaached
copies of E allele e allele (
EE 3 indiv 6 0
Ee 2 indiv 2 2
freq= 0.8 freq= 0.2 (1 POINT)
q sq = # individuals with attached earlobes: 0.04 (10,000) = 400 (1 POINT)
b) If 2 of the original colonists died before they reproduced offspring, the ratio of genotypes could be quite different in the subsequent generations. This is an example of ? (1.5 points)
GENETIC DRIFT OR BOTTLENECK
c) After many generations, the population on this planet has an unusually high incidence (occurrence) of color blindness. This is most likely due to ? (1.5 points)
FOUNDER EFFECT (1.5 POINTS)
BOTTLENECK (1 POINT)
INBREEDING (1.5 POINTS)
INBREEDING + _________ (1 POINT)
4) What is the purpose of the Hardy-Weinberg Equilibrium in Biology ? (3 points)
HWE ACTS AS A NULL HYPOTHESIS FOR THE STUDY OF EVOLUTION OF POPULATIONS. IF WE CAN PREDICT WHAT CAN HAPPEN IN THE ABSENCE OF EVOLUTION THEN WE CAN ESTIMATE THE EFFECT OF DIFFERENT PHENOMENA THAT CAN CAUSE EVOLUTION (MUTATION, MIGRATION, SELECTION, SMALL POP SIZE SINCE DRIFT CAN PLAY A ROLE AND NON-RANDOM MATING).
5) Discuss one experiment clearly that could be performed to determine if true ecotypes are present along a moisture gradient (cline) from very dry habitat (xeric) to an almost "boggy" habitat (mesic or very wet). Provide a clear description of the experiment and the results one would expect. (3 points)
NAME ALONE (0.5 POINT) EACH
EXPLANATION WITHOUT NAME (1 POINT) EACH
NAME AND EXPLANATION (1.5 POINT ) EACH
WRONG ANSWER BUT INTERPRET IN RIGHT/CORRECT DIRECTION (0.5 POINT)
2 POSSIBLE ANSWERS FOLLOWING ALONG THE LINES OF CLAUSEN KECK AND HEISEY - PLANT WORK ALONG AN ALTITUDINAL GRADIENT.
1. RECIPROCAL TRANSPLANT - PLACE EACH IN NOVEL AND HOME ENVIR. ALL GO THROUGH TRANSPLANT SHOCK
2. COMMON GARDEN - PLACE IN A NOVEL ENVIR FOR ALL AND SEE WHAT HAPPENS.
IF TRUE ECOTYPES THEY WILL ESSENTIALLY MAINTAIN THEIR STATURE/HEIGHT DIFFERENCES IN BOTH THE RECIPROCAL TRANSPLANT OT COMMON GARDEN. THUS THERE IS A GENETIC BASIS AND IT IS NOT PHENOTYPIC PLASTICITY BEING OBSERVED FOR THIS PARTICULAR TRAIT (OR WHATEVER TRAIT THE STUDENT USES)