Skill Review A-F

01 Sociology

M: Today, class, we’re going to be continuing our examination of the nature versus nurture debate regarding human behavior. On the nature side of the argument, we have the belief that genes are more important than the environment in determining human behavior. Proponents of the nature argument believe that all human behavior is inherent and innate. This means that we are born sort of “pre-wired” to behave in a certain manner. Got it? OK, conversely, people on the nurture side believe that instead of being born pre-wired, the mind is a blank slate at birth. This means that we are born without any predispositions, that our genes do not influence our behavior. All of our behaviors are a result of experience and conditioning. What do you guys think?

W1: Well, come on. Obviously, it can’t all be in the genes. I mean, we have free will.

W2: But then again, I don’t really see how it could be all environment

either. I mean, look at those twins you always hear about --- you

know --- they’re separated at birth and grow up in completely

different environments, but then they turn out to have a lot in

common.

M: I’m glad you brought that up, Ellen. Twins can tell us a lot about

our genes. Think about it. Identical twins share 100% of their

genes. In the womb, the egg splits in two after it has been fertilized

by the father’s sperm. Because the split happens after conception,

the genes are the same. The twins come from the same egg and

the same sperm, so they have the exact same set of genes. That’s

why they look exactly the same.

Fraternal twins, on the other hand, have a different set of genes.

In this case, two eggs are released, before conception. Then, the

two eggs are fertilized by two different sperm. Fraternal twins

are no more alike, genetically, than any other pair of siblings.

Normally, they share about 50% of their genes. So, by comparing

the similarities and differences we see in identical twins with

those in fraternal twins, we can learn about the influence that

genes have on human behavior.

Think about intelligence. Some believe that people are born with

a predisposition for intelligence. Others think that environmental

factors influence how smart a child will grow up to be. So,

researchers conducted a study that compared the intelligence

of fraternal twins with that of identical twins. Now, all of these

twins were from wealthy families, so we can assume that they

had similar environmental advantages --- good schools, good

educational resources, etc. Now, they found that genetic

predispositions accounted for most differences in intelligence.

In other words, the studies found that with regards to intelligence,

identical twins were more alike than fraternal twins. That means

that genes do play a role.

W1: So, you’re saying that it is more common for identical twins to

have similar IQs than it is for fraternal twins to have similar IQs?

M: According to this study, yes.

W2: OK, but come on. Intelligence can’t all be in the genes. Think

about the implications. Surely there are studies that support the

nurturists.

M: Indeed there are. Researchers looked at the IQs of both fraternal

twins and identical twins who were raised in adequate conditions

with those of twins raised in poor conditions. What they found was

that when poverty is considered, environment is more important

than genes.

W1: Wait a minute! How did they figure that?

M: Well, twins raised in adequate conditions have less intellectual

variation than those raised in poor conditions. Remember the first

study when the environment was controlled, or kept the same?

Identical twins were more alike than fraternal twins. All of these

twins had the same educational advantages. What the next study

found was that identical twins without educational advantages

were not as similar as those who had them. Understand?

W1: I think so.

M: So, as you can see, nature and nurture are not mutually exclusive.

Human behaviors are a result of an interaction between genetics

and the environment. Of course, nobody believes that human

behaviors are entirely genetic, but research such as twin studies

suggests that there is probably a role for the genes in shaping

the people we become.

02 Biology

  w:    

Everyone knows that the giant squid is, well, giant. It’s extremely
large, up to fourteen meters long. If it were swimming next to
your boat, you’d definitely notice it. If it were swimming next
to you in the ocean, you’d probably want to get out of the water
as soon as possible. In any case, if there’s a giant squid nearby,
someone is going to see it, and obviously, people have reported
first-hand accounts of giant squid sightings. The squid appears
in all sorts of drawings and stories, dating back hundreds of years.
It even appears in Herman Melville’s classic, Moby Dick, published
in 1851. However, even though it’s easy to see when it shows
up, it just doesn’t seem to show up that often. This species has
never been scientifically observed alive in nature. It has never
been filmed, and there are no pictures of a full-grown specimen.
Around fifteen dead ones are found every year, but there is not
much we can learn from dead specimens. Several juveniles were
caught near New Zealand in 2003, but very little was learned
from them, since they all died soon after capture.
So, where are all the squid you may ask? They must be somewhere.
After all, other animals eat them. They are common prey for
sperm whales. Scientists have often found squid parts in the
stomachs of sperm whales. Also, whales have been caught with
scars on their bodies, which look like they were made by the
suckers of squid tentacles. These suckers have rows of teeth,
like oversized needles. If sperm whales often eat giant squid,
then the squid must be fairly plentiful. In addition, the whales
must know where the squid are. In fact, a recent attempt to find
giant squid actually used sperm whales themselves. Scientists
placed special video cameras on the whales. The scientists hoped
that the whales would go looking for squid to eat, and in the
process, would collect some useful video footage of the squid.
This may have been a good idea. The whales did dive down to
several hundred feet, so maybe this is where the squid live.
Unfortunately, they found no squid, and the cameras only
recorded black water.
What makes the giant squid so elusive? The most widely
accepted theory is that the giant squid simply move around a lot.
According to this hypothesis, the squid normally live about two
thousand feet below the ocean’s surface. This is where they do
much of their feeding. We assume that these squid eat mostly fish.
Fishparts, particularly lantern fish, have been found in the bellies of
dissected giant squid corpses. Because they are so big, the giant
squid must eat a lot of fish. This means they’re going to have to
spend much of their time looking for sufficient food supplies.
They wouldn’t stay in any one place for long. The animals are also
going to be looking for food at different depths. This explains why
squid have been seen on the surface of the ocean at certain times.
It may even be that giant squid mate at higher
depths. All of this makes finding giant squid very difficult.
There are some problems with this theory that the squid are
always moving around, though. The most important one is that
the squid, as I stated before, are frequently eaten by sperm
whales. There are clearly enough giant squid to provide the
whales with a lot of food, and the whales know where to find
these squid in large numbers. If the squid really moved around
so much that even one is difficult to find, how can sperm
whales find and eat them so easily? It may be that the squid
move to certain places at regular times. Sperm whales may
know where these places are, and when the giant squid will be
easy to find there. For the time being, there is no clear answer.