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You have approximately ONE hour to answer all the questions. For multiple choice questions, write the LETTER of the answer in the margin. There is only ONE answer for multiple choice questions.
Answer all other questions IN THE SPACE PROVIDED. Most can be answered with a single word or a single sentence. I will instruct the reader to stop reading an answer when it hits the end of the space provided.
PUT YOUR NAME ON YOUR TEST!
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1) [3pts] All of the following statements about ecology are correct EXCEPT: _____C
a. Ecologists may study populations and communities of organisms.
b. Ecological studies may involve the use of models and computers.
c. Ecology is a discipline that is independent from natural
selection and evolutionary history.
d. Ecology spans increasingly comprehensive levels of organization,
from individuals to ecosystems.
e. Ecology is the study of the interactions between biotic and
abiotic aspects of the environment.
2) [3 pts]What is the main accomplishment of the "Modern Synthesis" ? _________D
a. popularized Watson and Crick's discovery of the structure of DNA
b. refined Lewontin and Hubby's electrophoretic techniques used to
determine the relatedness of species
c. linked DeVries' mutations with genetic change
d. incorporated genetic theory with Darwinian natural selection
e. disproved Lack's theories of Kin Selection
3) [4 pts] If a flock of flamingoes was wafted over the Atlantic by the winds of hurricane Ivan and landed (after the storm of course) on the island of Jamaica, what characteristic of the flock would immediately tell you the kinds of factors that would or would not affect the genetic variability of the population in the future.
Its size.....or Population size....
4) [6 pts] In the 50/500 rule of conservation ecology, What do the 50 and 500 refer to?
5) [2 pts] In one sentence ONLY, what is Ernst Mayr's species concept (the one that we are going to use for this class as a practical measure).
Two populations that are reproduvtively isolated ....(cannot sucessfully interbreed, reproduce with each other, etc.etc.)
6) [6 pts ]Here is a hypothetical starch gel showing a gene at a single locus for all the individuals in a small population of hairstreak butterflies in the coastal sage scrub of the Baja peninsula (the DNA was obtained non-lethally by removing a small piece of wing on the adult butterflies).
a. What is the heterozygosity of this population?
25%
b. What is the most likely fate of this population?
Extinction, or loss of alleles
c. If there are other populations in the area, what may change the fate of this population?
introgression, gene flow, emigration, etc.
a. Sympatric
b. Allopatric
c. Allelopatric
d. Tetraploid
e. Polyploid
8) [5 pts] If you look at the evolutionary trees of beetles and flowering plants what about their patterns of evolution will suggest to you that beetles probably didn't evolve with plants in a PARASITIC relationship? Their phylogenetic trees do not overlap closely
9) [4 pts] Beetles diversified after they began feeding on flowering plants. What was a probable cause for this diversification hinted at by the description of the plant-beetle relationship as a "biological arms race".
The angiosperms developed (evolved) diverse secondary compounds (chemical defenses) and the beetles responded by specializing on detoxifying or using these compounds.
10) [ 2 pts] What is a likely cause (besides humans) of historical mass extinctions on this planet?
Asteroid/comet/meteor impacts (and or excessive volcanism)
b. What evolutionary OPPORTUNITY does a mass extinction open up for the survivors?
Extinctions open up new niches for survivors
11) [5pts] Some trees such as Bois D' Arc (pronounced bo - DARK) or honey locust have large, fleshy fruits that very few things seem to eat. They also have relict distributions. What is the probable cause of a relict distribution in these types of trees?
Extinct seed dispersers .......(seed disperser was part of the now extinct pleistocene megafauna)
12) [4pts] What are the two most common causes of extinctions in currently existing species?
Habitat loss, invasive species
b. Name two characteristics of the kinds of species that are most susceptible to extinctions.
Confined to islands, small population size, slow reproducion, poor disperser, highly specialized, variable population size, high trophic level, short life span, rare.
13) [4pts] Which of these is a proximate explanation?________________________________B
(15) [6 pts] Under Hamilton's rule (B/C > 1/r) why are haplodiploid organisms more likely than diploid organisms to altruistically give up having children to care for their own sisters?
Haplodiploid sisters are more closely related to each other than to their own offspring. In a haplodiploid system B/C > 1/r is easier to meet than under the diploid mating system (B/C>1.3 easier to achieve than B/C>2)
(16) [6pts] Mexican Spiny pocket mice have 2-8 offspring depending on how much food there is. The food to mean offspring ratio is given by the following figure. The mice need one gram of food per week to survive without reproducing.
If a pocket mouse were living with her sister under what nutritional circumstances might she exhibit kin-selection behavior?
Justify your answer using Hamilton's Rule.
(18) [4 pts] Name two advantages and two disadvantages to living in groups that may moderate group size.
Extra mating opportunities, increased protection from predation, increased ability to find food
Attract more predators, increased competition for food, mates, etc.
(19) [ 4pts] Answer ONE of the following two questions
a) What part of the general flux equation (Flux=Area X Gradient X Conductance) does the Beldings Ground Squirrel MOST alter by going into torpor? Justify your answer in 1 or 2 sentences.
(b) What part or parts of the general flux equation do plants alter the most when they locate their stomata in a hair filled pit.
How does having stomata in a hair filled pit allow plants to alter the flux equation in those ways?
Conductance and Gradient
The hairs slow the air flow across the leaf, the pit keeps the stomates out of the wind. Both of these adaptations allow the leaf to keep its boundary layer intact keeping a lower gradient between the inside of the leaf and the surrounding environment (thus they lose water more slowly)
(20) [6 pts] What two major, opposing fluxes must terrestrial green plants balance in their leaves?
Water and CO2
Name one adaptation per flux that plants use to balance these two fluxes.
Water- light colored, smaller, vertically oriented, leaves, waxy cuticle on leaves, stomates in pits, hairy leaves, deciduous leaves, leaves converted to spines with photosynthetic stems instead.
CO2- C4, CAM photosynthetic pathways
(21) [4pts] Which of these hypothetical soils will have the greatest field capacity. ?_________B
(22) [4pts] Answer ONE of the following two questions.
a) How do plants growing in deserts increase the water potential of their roots in order to extract water from the dry soils?
They increase the amounts of solutes in their roots.
b) What are three adaptations that the Kangaroo Rat uses to conserve water in hot, dry, environments.
Large nasal passages
Efficient kidneys
Nocturnal behaviour
(23) [4pts] Which of these is NOT an adaptation of plants to hotter, drier conditions__________A
(24) [2 pts] Which of these characteristics is typical of an iteroparous organism?_________D
(25) [4pts] Some tree species like oaks and chestnuts produce lower numbers of seeds for four to five years, then all the individuals in an area produce a very large number of seeds all at the same time in the same year. This is called "mast" fruiting. Studies of oak seedling survival have found that a few seedlings produced in a mast year tend to survive, but usually no seedlings produced in non-mast years survive. a) Why are these trees considered iteroparous, even though they share many characteristics with semelparous organisms?
They reproduce more than one time
b) Aside from chance (i.e. more seeds means that there is a higher probability for a seedling to survive by chance) how might mast fruiting increase survivorship of seedlings?
They overwhelm or "flood" seed predators with more food than they can possibly eat.
(b) Justify your answer in one to four sentences.