Category Archives: science

Wrinkly fingers for gripping?

So, here’s the latest in adaptationism:

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Hat-tip to Justin Blumenstiel, who is the king of transposable elements, which I think means that every time one of them transposes, they have to tithe to him.

Changizi M, Weber R, Kotecha R, & Palazzo J (2011). Are Wet-Induced Wrinkled Fingers Primate Rain Treads? Brain, behavior and evolution PMID: 21701145

Happy Belated Father’s Day

So, Farther’s day was almost a week ago, but I wanted to share this video, which illustrates all the good-timey ho-down fun that led to your father becoming your father.

Did I just call your mom a ho?  It sure seems like it, doesn’t it?

If you want to try this (or something like it) at home, check out the ideas in this article:

Joseph P. Chinnici,, Joyce W. Yue,, & Kieron M. Torres (2004). Students as “Human Chromosomes” in Role-Playing Mitosis & Meiosis The American Biology Teacher, 66 (1), 35-39

Happy 99th Birthday, Alan Turing

So, today (June 23, 2011) marks the 99th anniversary of the birth of Alan Turing, British supergenius who played a critical role in winning World War II and is one of the founding fathers of computer science.

He was also gay, which was illegal Britain at the time. In 1952 he was prosecuted under the same law that had sent Oscar Wilde to gaol. He chose to undergo chemical castration (in the form of treatment with feminizing hormones) as an alternative to prison.

In 1954 he committed suicide in dramatic fashion. He died of cyanide poisoning, and was found lying in his bed with a half-eaten apple beside him. The speculation is that he had laced the apple with cyanide and was reenacting the apple scene from Snow White.

When Alan Turing was found on June 8, 1954, he had been dead for one day, and he looked exactly like this. Snow White by *VinRoc on deviantART

Turing’s earliest major contribution was the hypothetical Turing machine, which consisted of a very long piece of tape and a set of rules for manipulating the symbols on that tape. Turing showed that such a machine was, in principle, capable of performing any mathematical computation that can be represented as an algorithm. The Universal Turing Machine (a Turing machine capable of simulating any other Turing machine) provided a sort of proof-of-principle for the idea of general-purpose computers, and the tape-and-manipulator structure of the Turing machine is often cited as the prototype of the separation-of-hardware-and-software structure that pervades our computer lives today.

A Turing machine consists of a tape with symbols on it and a machine with a set of rules for reading and manipulating those symbols. And a bell.

During World War II, Turing worked as a cryptanalyst and made major contributions to cracking the “Enigma” codes used by the German military. The success of Turing and his colleagues throughout the war gave the Allies a critical advantage, particularly during the early parts of the war, when the Germans had a significant military advantage.

After World War II, he introduced what we now call the “Turing test” for artificial intelligence. The idea is that a computer can be said to have achieved genuine intelligence if a human having a conversation with it could not tell that it was a computer. For the next forty-some years, this was considered to be the gold standard for the demonstration of human intelligence. Then came a flood of reality television, which demonstrated that many humans would not actually pass it.

During the last few years of his life, Turing turned his attention to certain problems in mathematical biology, including the curious fact that many plants seem to grow in patterns governed by the Fibonacci sequence. The whole phyto-Fibonacci thing is a weird and interesting phenomenon that will get its own dedicated post sometime soon.

In the meantime, happy birthday Alan Turing, and RIP.

Turing, A. M. (1950). Computing Machinery and Intelligence Mind, 59 (236), 433-460

Antibiotic resistance and corporate agriculture

So, over the weekend, Nicholas Kristof wrote a nice piece in the New York Times in which he laid out the basic facts and statistics regarding the cavalier use of antibiotics in agriculture. His column is full of interesting (i.e., depressing) figures, one of the most striking of which is that the agricultural use of antibiotics in the state of North Carolina exceeds the medical use of antibiotics for the entire United States.

Anyway, the basic punchline is this: when someone in your family is hospitalized or killed by some food-borne, antibiotic-resistant pathogen, you can thank the huge agricultural corporations and the millions of lobbyist dollars they have spent blocking food-safety legislation.

Happy eating!

These full-page comics come out badly here on the blog, so to see a more readable version, go to the Darwin Eats Cake website.

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Sørensen SJ, Bailey M, Hansen LH, Kroer N, & Wuertz S (2005). Studying plasmid horizontal transfer in situ: a critical review. Nature reviews. Microbiology, 3 (9), 700-10 PMID: 16138098

Traffic, preterm birth, and adaptationism

So, here’s a thing:

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This relates to a criticism that I made of evolutionary psychology, but which applies to many naive adaptationist arguments: it is easy to come up with a plausible-sounding adaptive explanation of just about anything. In most cases, it is equally easy to come up with an equally plausible-sounding explanation of the exact opposite phenomenon.

Barnett AG, Plonka K, Seow WK, Wilson LA, & Hansen C (2011). Increased traffic exposure and negative birth outcomes: a prospective cohort in Australia. Environmental health : a global access science source, 10 PMID: 21453550

White Rock paint core

So, I grew up in the science town of Los Alamos, New Mexico, which is actually sort of two towns: Los Alamos and White Rock. The two towns share a lot of things, including a Sonic, a middle school, a high school, and a love of very large bombs.

Well, at the entrance to White Rock (right next to the quickie mart) is the eponymous rock. The white rock is only sometimes white, as it is a long-standing tradition to paint it in different colors an patterns.

Well, apparently Mouser NerdBot (who is, I assume, based on the name, a Palin relation), was curious just how thick the paint was and took a core sample, discovering that it was five and a half inches thick.

Here’s a small version of the composite picture, but you should really check out the full-size image here.

via kottke.org

Five and a half inches!?! That’s like twice the size of my . . . um . . . pet hamster?

I can haz rapshur? Endgame effects.

So, you’ve probably heard that the world is ending this Saturday (or, as Tom Scocca explains, sometime between Friday evening and Sunday morning, depending on how the rapture interacts with the time zones). You may already have signed up on Facebook to attend the pre-rapture orgy and/or the post-rapture looting.

Earlier, I posted my discovery that you can be taken up by the rapture even if you’re actively engaging in gay sex when it happens, which is pretty awesome.

But now I want to talk about the timing issue.

Back in January I wrote a post making fun of Harold Camping’s claim that he knew when the rapture was coming. The biblical counter-argument comes from Matthew 24:36, which, in the standard Lolcat edition, reads:

but bout dat dai or hour no wan knows, not even teh angels in heaven, nor teh son, [e] but only teh fathr.

(The non-biblical counter-argument, of course, is, “Wait, what? That’s just stupid.”)

The punchline in my previous post was a variation of the standard one that people like myself like to drop in these situations. In this case, it was, “Look! An evolutionary biologist who was raised in a Unitarian church with an atheist minister knows more about the bible than Harold Camping! Hahahaha!”

This is the bible translation favored by Lost in Transcription.

In fact, this is just one of several places in the bible that emphasize the unpredictability of the rapture (and/or the second coming, which is maybe a different thing — who knew?).

So, what’s that about, then? What it reminds me of is the phenomenon of endgame effects in economic games. If you’re not familiar with endgame effects, well, actually you are, because it is one of those regularities that shows up in life just as much as it does in experimental economics.

I’ll describe this in terms of a public goods game, but the phenomenon occurs in a variety of contexts. In your standard public goods game, players are given some money. Each player chooses how much of their money to contribute to a common pot. The money in the pot is then multiplied by some amount (e.g. 3X), and then divided equally among the players, without regard to whether or not they contributed.

Nice picture illustrating the basic structure of a public goods game. I poached this one from Ben Allen’s blog, which would make him a cooperator, since he made this slide. I would be a defector, since I am freeloading off of his work.

The group as a whole benefits most if everyone puts their whole endowment into the pot. But, each individual gets their best payoff if everyone else donates to the pot, but they don’t. If you run this experiment over and over, you find that people typically start off making a decent contribution (typically ~ 50%), but the contributions decline over time, until eventually pretty much everyone is putting in nothing.

A standard modification, then, is to incorporate a punishment phase after each round of the game. For example, people might be given the option to pay some money in order to have money taken away from one of the people who did not donate to the pot.

The first interesting finding that gets reproduced again and again is that people are willing to pay to punish defectors. The second standard finding is that incorporating a punishment phase stabilizes cooperation. So, given the threat of punishment, people will continue to donate to the pot at a high level.

I was going to write something like, “Punishment in most behavioral economics experiments is monetary rather than physical,” but all I can think is, “This is so wrong on so many levels.” Why do you do this to me, Google? 

Okay, so here’s where the endgame effect comes in. These experiments are typically set up to run a certain number of rounds. Whether the experiment lasts for ten rounds or twenty or a hundred, people will start defecting (contributing less) in the final few rounds. Presumably this is because they know that there will be less opportunity for them to get punished, so they maximize their short term gains.

Now, let’s say you’re starting a religion, and you want to influence people’s behaviors. The first thing you do is you set up a system of rewards and punishments (e.g., heaven and hell). Next, let’s say that you want to be able to convert people. Well, one thing you might do is set up a reset button, say, in the form of forgiveness. This allows you to go up to someone who has not been following your rules, explain to them about the system of rewards and punishments, and tell them that they have the chance not to be punished for their past behavior if they ask for forgiveness and act right moving forward.

This structure sets up a well known issue facing Christianity. In principle, one could completely disregard all of the rules, and then repent at the last minute. If your goal is to get people to act right all the time, one thing you can do is introduce uncertainty about when the reward or punishment is going to be doled out. In fact, this seems to be the explicit goal in many of the relevant passages.

This saying, attributed to George Carlin (or occasionally Rowan Atkinson) can be found on t-shirts, mugs, mouse pads, and bumper stickers. It is sometimes used by actual religious folks, who are either missing or reappropriating the irony.

Matthew 24:43-44 compares the second coming to having a thief break into your house:

but understand dis: if teh ownr ov teh houz had known at wut tiem ov nite teh thief wuz comin, he wud has kept watch an wud not has let his houz be brokd into. so u also must be ready, cuz teh son ov man will come at an hour when u do not expect him.

And the parable of the Ten Virgins (Matthew 25:1-13) is about always being prepared:

“At that tyme the couch of the cieling will be like 10 gurlz who can has some flashlites and go meetz teh man at teh door. 5 wur stoopid and 5 wur not stoopid. Teh stoopid gurlz gotz flashlites, but no baterys. Teh not stoopid onez brot baterys. Teh man wuz gonna be rly late, n tey al took a nap.

“In teh night some dood yelld: ‘It’s teh man! Go meets him!’

“Then al teh gurlz wok up n turnd on teh flashlites. Teh stoopid gurlz said to teh not stoopid gurlz: ‘I can has ur baterys? Mine r dead.’

“‘No’ teh not stoopid gurlz said ‘These r mah baterys! Go buys some.’

“But wile tey wur gone buyin teh baterys, teh man arived. Teh not stoopid gurlz went in wit teh man to his crib to parteh n tey close teh door.

“Latr teh stoopid gurlz came. ‘Dood!’ tey said ‘We r outsid r door, waitin for u to let us in!’

“But teh man said ‘Who r u? Go away, this is mah parteh!’

“So keep redy for teh couch of the cieling, cus u don’t kno wen Jebus is comin bak.

So, the whole thing seems structured to deal with this aspect of human nature that has been shown by lots of different economics experiments, but is well known to you from everyday life, as it was well known to the people writing the new testament two thousand years ago: people will cheat if they think they can get away with it.

Bad behavior is something that you can get away with right up until the point where you can’t.

Selten, R., & Stoecker, R. (1986). End behavior in sequences of finite Prisoner’s Dilemma supergames A learning theory approach Journal of Economic Behavior & Organization, 7 (1), 47-70 DOI: 10.1016/0167-2681(86)90021-1

1971 Canadian Evolution Video

So, do you remember 1971? Me neither. As I understand it, everyone was on drugs. And in Canada, they were all on METRIC DRUGS!!

This video is a little on the long side for the 2011 sensibility, but is pretty awesome. There are a couple of the things in particular that I like about it. First, most videos that I have seen illustrate evolution by having organisms transform. You know, like you have the fish who swims to the edge of the land, wriggles out, and grows legs. Unfortunately, I think that can reinforce two surprisingly common misunderstandings about evolution: (1) that it involves organisms changing adaptively during their lifetimes, and (2) that it involves a degree of intentionality.

That’s not so say that those video makers misunderstand the evolutionary process, just that the most common way of presenting the process to a broader audience lends itself to a particular misinterpretation.

In this video, novel forms arise as offspring, often to the noticeable surprise of their parents. Also, some of those novel forms are adaptive, while others are not.

Here’s the second thing. Videos like this always face a challenge: how do you illustrate mating and reproduction without traumatizing the children? This video comes up with some awesome mating procedures, from eyeball things smashing into each other to a system that involves the male blowing into the female’s nose.

Confidential to my wife: I’ve got an idea for later.