Dr. Reichler’s Bio 301M   MWF 9-10am    Print Name:______________KEY_________
Exam #1   February 14, 2007

    Read each question carefully and don’t hesitate to ask if a question seems unclear.  If possible, answer each question in the space provided, but if needed, continue on the back.  If you use a drawing as part of your answer, be sure to also include a written explanation. These questions have specific answers, although for some, more than one answer is possible.  To receive full credit you must clearly and fully answer the question being asked.  This exam is worth 103 points with the points for each question noted in parentheses.

1. Using rules one and two of Strong Inference answer the following question:  Who are people in the Middle East most closely related to? (8pts)
Should propose at least two hypotheses and one experiment to eliminate the hypotheses.  For example:  Hypos- Middle Easterners are most closely related to Europeans.  Middle Easterners are most closely related to Asians.  Middle Easterners are most closely related to Africans.  Expt- Compare the mtDNA od people from these regions and see who has the fewest differences with Middle Easterners.

2. You read a report stating that introducing wolves into Yellowstone NP has increased the number of fish in the streams.  The researchers measured the number of fish currently in the streams.  Did these researchers use Strong Inference?  Why or why not? (6pts)
No.  Because they did not try to disprove any hypothesis, they only have data from the current time.  OR  They did not get reliable results because they have no controls.  OR  They only had a single hypothesis.

3. Why do you have more of your mom’s DNA than your dad’s DNA? (6pts)
MtDNA is inherited only from mom, so each of us inherits just a little more DNA from her.

4. Some organisms have much more DNA than humans do.  Does this mean that they can make a greater diversity of proteins than humans can?  Why or why not? (8pts)
Not necessarily.  They may have more non-coding DNA.

5. Differently from most people, you find that the time it takes Frank to find a snake in a background of flowers is the same as the time it takes him to find a flower in a background of snakes.  Can this difference between Frank and most other people be attributed to a difference in DNA?  Why or why not? (6pts)
Yes.  Most humans have some inherent ability, some genes that are inherited, to more rapidly detect certain threats such as snakes or spiders.  Frank must lack some of these genes.

6. Both humans and wolves live in groups.  How is the advantage gained from forming groups different between humans and wolves? (8pts)
Human groups give protection, probably from other humans.  Wolf groups are better able to capture prey- obtain food.

7. Can measuring how long an individual lives be used to determine their evolutionary success?  Why or why not? (8pts)
No.  Evolutionary success is measured by passing on genes- having offspring and those offspring reproducing etc.  Living a long time may or may not be an indication od number and fertility of offspring.

8. If the mutation rate of mitochondrial DNA were 1 mutation every 500,000 years (this is much longer than the actual rate), would you be able to determine the difference between the “out of Africa” and multiregional hypotheses?  Why or why not? (8pts)
No.  The out of Africa hypothesis states that humans have a common ancestor about 100,000 years ago.  If the mutation rate was 1 per 500,000 years, then there would be no way to detect recent differences in people’s DNA.

9. When researchers compared individual’s mitochondrial DNA, they found people from different geographic locations with similar mitochondrial DNA sequences.  What does this indicate about our ancestors’ behavior? (8pts)
They must have commonly migrated.  The spread of different DNA throughout the planet shows this pattern of ancient migration.

10. In the experiment where the researchers shocked the participants depending on which picture they were shown.  Did individuals of the same skin color give similar results to snakes or flowers?  Why? (6pts)
As flowers.  For flowers, fear irrelevant, and people of the same skin colors, the nervousness desisted after the shocking, negative reinforcement, stopped.

11. When researchers were studying the effects of the reintroduction of wolves, why did they measure the depth of gullies where streams were located? (8pts)
They were looking to see if wolves had changes the elks behavior by changing where the elks were feeding.  Deep gullies are considered high risk areas for the elks as they can be easily ambushed by the wolves in deeper gullies.

12. Would you expect there to be more wolves or elk in Yellowstone NP?  Why? (6pts)
Elk.  They are secondary consumers, so the elks eat plants, use most of that energy for living and only a fraction of the energy the elks eat is available for the wolves.  So less energy available limits the wolf carrying capacity.

13. How could researchers determine an animal’s response to the mirror test without needing to manipulate the animal (by simply observing the animal)? (6pts)
By observing if they act differently than when presented with a “stranger”.  If the individual recognizes themselves, they would act differently than when they see another animal.

14. How could we increase the carrying capacity of humans on earth? (8pts)
By reducing the resources we use, OR by more effectively removing waste products.


Bonus:  Over the same period of time, why would the number of mutations present in nuclear DNA be higher than in mitochondrial DNA?  (3 pts)
Because the nuclear DNA has more non-coding DNA.  Mutations in coding regions are typically fatal, and therefore not passed on.  So since mtDNA has very little non-coding DNA, the number of mutations for a given time that get successfully passed on would be lower.