Download Exam 2

Biology 4415
Name (yours:)_____________________________
Exam 2
1. Fill in the blanks! Fill in the blanks! Use one letter per blank. When you’re done,
the first letters of each word, read downwards, will give you the answer to this
question:
Charles Darwin’s grandfather was interested in “spontaneous generation” (the
possibility of life coming from non-living things). The story goes that he did
chemical experiments on pieces of pasta, and actually got a noodle to move around
under its own power. This is probably untrue—but the story inspired an English
author to write a novel about a scientist who created a living being in his lab. What
is the title of the novel? (15 pts. total)
__ __ __ __ __ __ R
“___ Effect” refers to chance changes in allele
frequency in a new population
__ __ __ __ H __ __
Toothed wheel that turns only in one
direction; refers to a model that explains
why sex is evolutionarily beneficial
__ __ __ R __ __ __ __
Giving up a benefit in order to help another
__ __ __ – __ __ __ __ __ __ I __ __
Theory formed by the fusion of natural selection
with Mendelian genetics
__ __ __ __ __ T __ __ __
The number and types of chromosomes that an
organism has
__ __ __ __ L __ __ __ __ __ __
Gould and Eldredge developed the theory of
punctuated _________.
__ __ __ __ E
The “ecological species concept” defines a species
by its ________
__ __ __ __ __ __ __ __ C
Speciation without a geographic barrier
between populations
__ __ __ __ __ F __ __ __
Type of fault in which opposing tectonic plates are
sliding past each other
__ V __ __ __ __ __ __ __
Darwin himself preferred the term “descent with
modification” for this theory. . .
__ __ __ __ __ __ __ V __
Fitness that is calculated based on the reproductive
success of an individual and its kin
__ O
Have you ever had a better class in all your life?
. . . and the title of Mary Shelley’s famous novel is
“__ __ __ __ __ __ __ __ __ __ __ __”
2. For each of the following case studies or examples below, write a couple of sentences
explaining the general evolutionary principle that is illustrated. (5 pts. each; 25 pts. total)
a) The deepest part of the ocean is the Marianas Trench, nearly 36,000 feet deep. Parallel
to the Marianas Trench are the Marianas Islands, a chain of volcanic islands (including
Guam).
b) Raccoons (Procyon) and ringtails or “miner’s cats” (Bassariscus) are native to North
America, and fossil evidence shows that their ancestors have lived there for at least 37
million years. But raccoons and ringtails are closely related to a third genus, Nasua (the
coatis), which are found in Central and South America as far south as Brazil.
c) Speaking of raccoons. . . The common raccoon, Procyon lotor, is found throughout
Canada, the United States, Mexico, and Central America. Other species of raccoon are
restricted to individual islands off the North American coast. These include, in the
Caribbean, the Cozumel raccoon (Procyon pygmaeus), the Nassau raccoon (P.
maynardi), the Barbados raccoon (P. gloveraleni), and the Guadeloupe raccoon (P.
minor). The Tres Marias raccoon (P. insularis) is found only on the Tres Marias Islands
off the Pacific coast of Mexico.
d) Wilson’s phalarope (Phalaropus tricolor) is a small wading bird that breeds in saline
lakes in the western United States. After mating, the females migrate to South America,
while the males incubate the eggs and care for the young. Female phalaropes are more
brightly colored than males, actively pursue male mates, and compete with each other for
“breeding rights”.
e) In the wood mouse, Apodemus sylvaticus, females in estrus mate with multiple males.
Male sperm cells have hooks on the heads. The sperm cells from each male link up into
giant “sperm trains” of thousands of interlocked sperm, which move twice as fast as
single sperm cells could move.
Now pick any four of the following seven questions and answer each in a wellreasoned, clear, concise essay, preferably of one or two paragraphs. Each is worth
fifteen points.
3. Many systematists (scientists who study biological classification itself) argue that
Linnaean taxonomy should be junked. Why might they hold this opinion?
4. Jim Holt was a Republican candidate for the US Senate in 2004. In an article
published in the Echo on October 28, 2004, titled “Lincoln, Holt portray ideals for
hopeful senate seat position”, Holt stated his position on gay marriage. He was quoted
as saying “Even if there was no god, the laws of nature tell us that homosexual unions
are not natural. No homosexual can reproduce. They can only recruit. If the law of
‘survival of the fittest’ applied in this instance, their existence could not continue.”
Comment on Holt’s statement from the viewpoint of evolutionary biology. How is it
possible—or is it possible?—for the existence of homosexuality to be consistent with
natural selection, if homosexuals don’t reproduce? (Although I’ve known both male
and female homosexuals who have had kids in more or less the normal way.) Do your
best to keep your answer as politically neutral and as free from invective as possible.
Stick to discussing testable hypotheses and tested theories.
5. One interesting problem for evolutionary biology is how to explain menopause, the
ending of a woman’s childbearing years. One might predict that any mutation that
shortened a woman’s lifespan after menopause would not be selected against, since it
couldn’t affect the number of children born. By the same token, any mutation that
lengthened the childbearing years, postponing or preventing menopause, might be
selected for. Despite these theoretical arguments, women may live for several decades
after ceasing to menstruate. Come up with two evolutionary hypotheses for why humans
go through menopause, and briefly outline how they could be tested. (HINT: One
hypothesis might have something to do with kin selection. . .)
6. This just in:
http://www.cnn.com/2004/TECH/science/07/23/fiddlercrabs/index.html
(CNN) -- There's no formal neighborhood watch program, but fiddler crabs in
Australia know a thing or two about preserving a safe place to live.
Scientists have found that when an "outsider" male threatens to take over
another male's burrow, nearby residents help their neighbor defend his
territory.
And in most cases, that cooperation helps the neighbor hold his ground. Males
most often help out when the neighbor is smaller than the intruder, and
therefore more likely to lose the burrow. . . .
See if you can explain this interesting example of altruism. How would it be adaptive
for fiddler crabs to help their neighbors defend their territories?
7. Creationist author Luther Sutherland once wrote that Eldredge and Gould’s theory of
“punk eek” “amounts to tacit admission that anti-evolutionists are correct in asserting
there is no fossil evidence supporting the theory that all life is connected to a common
ancestor.” Discuss.
8. A “hot spot” and a subduction zone would both create groups of volcanic islands that,
in time, would evolve their own unique species of animals and plants. How might
speciation operate differently on each island group?
9. Male movie stars such as Harrison Ford, Sean Connery, Randy Quaid and George
Clooney show facial wrinkles and other very definite signs of age, yet are widely
considered to be sex symbols. Female stars, on the other hand, are rarely considered sexy
if they show signs of age, and in fact often go to great lengths to get rid of or cover up
any signs of age (ranging from makeup to palstic surgery). Come up with an explanation
proposed for this that draws on evolutionary biology.