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Mutant 1: Wolverine
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1. Wolverine's challenge: "We Mutants will grow and eventually replace you insignificant Normal human beings. You have nothing to say about it, so relax--Mutants produce only one child every other year, so in a hundred years you'll see only fifty of us."

What do you say to Wolverine?

"The Trouble with Tribbles" © 2006 CBS Studios Inc.

In a perfect environment such as the Enterprise, Tribbles do not age, so they live forever after producing each litter (unless they eat poisoned grain.) Therefore, after each "generation" there are ten plus one = eleven tribbles.

2. Uhura brought one tribble onto the Enterprise.

(a) Each tribble produced a litter of 10 (and kept living) every 12 hours. Calculate how many tribbles there should be in 5 days.

(b) Set up an Excel file to calculate the number of tribbles produced over 5 days. In Excel, plot your results (number of tribbles over time). Print a copy of the plot and the data table.

(c) What actually became of the tribble population on the Enterprise, and why?

3. During the poisoning, the population of tribbles drops to 100. Assume those tribbles are still producing 10 offspring per litter, but only half survive the poison, and the parent dies after one litter.
What is their new doubling time?

4. In an environment like the Enterprise:
a) How many tribbles would you need initially to produce 1 billion tribbles in 2 days?

b) How many hours would it take for 1 tribble to produce one billion tribbles?

5. In real-life natural environments, what phenomena limit the size of growing populations? State three different examples.

6. Tribbles are hermaphrodites (can fertilize themselves, or another tribble). They come in different coat colors, determined genetically. Suppose that Black color is dominant to White, but Brown is codominant with White (a brown allele plus a white allele makes a cream-colored tribble).

(a) If a pure black tribble mates with a white tribble, what proportion of offspring will be black?

(b) If a black offspring from cross (a) fertilizes itself, what proportion of offspring will most likely be black?

(c) If a cream-colored tribble fertilizes itself, what colors of offspring will appear, in what approximate proportions?