Shrodinger says that more than anything, humans eat because they need to decrease their internal entropy. Humans are highly ordered beings, and so must eat complex things to keep themselves that way. Another way of decreasing entropy is to decrease the temperature – based on our entropy formula (Delta S = q/T), where q is the amount of heat added to the system. At absolute 0, entropy is zero.

“Bombing” entails members of a community going to forums/chat rooms and writing lots of silly, inside-joke type comments.

]]>Professor Berry showed us several different population genetics charts in class. These usually have “generations” on the x axis and “% frequency of the allele on the y axis.”

For beneficial alleles, recessive alleles will increase in frequency slowly at first, but then become fixed (100% frequency in population). Beneficial yet dominant alleles, however, increase very quickly in frequency but plateau without reaching fixation. This is because the not-so-beneficial recessives can hide in heterozygotes without being expressed in the phenotype.

]]>- random mating
- no selection
- no migration
- no mutation

Of course, it’s hard to think of a species for which these assumptions hold. If a population is not in Harvey-Weinberg equilibrium, then we can detect evidence of evolutionary action (one of the above 4 is happening).

In the equation, p is the frequency of the dominant allele (A), q is the frequency of recessive (a).

p^2 = frequency of AA

2pq = frequency of Aa

q^2 = frequency of aa

p+q should also equal 1.

]]>This comic is a bit hard to parse. It comes from a well-known brainteaser about red and white hats. Basically, the prisoners can only see ahead of them and they can see the color of every hat ahead of them. They cannot see the color of their own hat or those worn by people behind them. Before the game starts, they can consult and make a strategy. They also know the total number of prisoners ahead of time.

Thus, the only strategy to save as many prisoners as possible is if the last prisoner (who can see all hats but his own) says **the color of which there is an even number. **(or odd number – but this has to be agreed upon by prisoners beforehand). He cannot save himself (50% chance) but he can save everyone in front of him.

Let’s say there are 3 people in line.

Red Red White.

The last prisoner sees 2 red hats. He says “red”. He is executed

The second to last prisoner sees an odd number of red hats in front of him. Thus his own must be red. He says “red” and is saved.

The first prisoner sees an even number of hats (0) in front of him. He knows that one red hat has been removed, so there must be an odd number left. Thus his own must be red. He says “red” and is saved.

———————–

I was thinking about this old brainteaser a few weeks ago and I realized that it’s very similar to the idea of the parity bit. By providing crucial information about whether there is an odd or even number of (1’s) in the code, the parity bit saves the rest of the code from error.

]]>Out of the mammals, kangaroos have a very low brain size-body weight ratio. It is hypothesized that they can be rather dull because they are isolated in Australia, where there aren’t very many predators. This among other reasons, of course.

]]>The 2nd movie proposal is about the formation of Eukaryotic cells. Scientists have found that chloroplasts and mitochondria have DNA very similar to bacteria. In fact, chloroplasts may even be cyanobacteria, in some sense. Early cells, which needed more membrane in order to produce lots of energy for more complex functions, ate early mitochondria and chloroplasts in a feast of phagocytosis and became Eukaryotic cells.

Proposal 3 hasn’t happened yet, fortunately.

]]>Vestigial organs are a great piece of evidence for evolution. They are organs that don’t really have any purpose today, but probably had some point in the evolutionary past. We can tell that at some point, whales were big mammals that walked around on land but decided to go back to water. Although their hind legs disappeared, they still have very sexy pelvises.

This comic references the Shakira song:

]]>H (# of bits) = – summation (pi log(2)pi), where pi is the probability that the symbol is found.

The comic makes reference to the fact that codes which use relative probabilities (rather than assume that all symbols occur at an equal probability) are usually more efficient. However, because the desired one speaks not, there is 0 possibility of any of the phrases that this “Secret Code” would code for, and since pi=0 everywhere, H = 0 as well.

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