Science

An episode of Blackadder I just watched makes a point relevant to recent discussion on the plausibility of alternatives to the theory of evolution:

Blackadder [to Baldrick]: If I don’t come up with an idea soon, in the morning we’ll both go to meet our maker. In my case, God; in your case, God knows — but I doubt he’s won any design awards.

I just got the latest issue of Scientific American, and noted with interest the Table of Contents, in which the Skeptic column promised an evolutionary explanation of the mutiny on the Bounty. I vaguely expected the usual stuff about alpha and beta males or somesuch, but I found that the ev psych boffins have come up with a startling new discovery. Young men like having sex. At this point the mathematics and biochemistry get a bit complicated for me (oxytocin is in there somewhere), but apparently this has something to do with the survival of the species.

Even more startling, though, is the fact that

Although Bligh preceded Charles Darwin by nearly a century,

he managed to anticipate this discovery. Who would have thought that a former governor of New South Wales (and not a successful one) would share with EO Wilson and Stephen Pinker the honour of founding evolutionary psychology? In Bligh’s words

I can only conjecture that they have Idealy assured themselves of a more happy life among the Otaheitians than they could possibly have in England, which joined to some Female connections has most likely been the leading cause of the whole business.

Delivery times are somewhat strange here in the Antipodes, and I thought perhaps I had an advance copy of the April edition, but the cover says February.

Via CNN.

The state’s school superintendent has proposed striking the word evolution from Georgia’s science curriculum and replacing it with the phrase “biological changes over time.”

From the details it looks like this is repeating the Kansan tragedy as farce, and since the proposal has bipartisan opposition this farce probably won’t go far. But don’t you just love a country where scientific theories that are accepted universally within the relevant scientific community are the subject of partisan disagreements? If this were happening in a tiny unimportant country it would be the stuff of late-night comedy. Instead, well it probably is a little tragic.

Michael Crichton has made millions by writing mass market thrillers that either regurgitate partially understood scientific factoids, or pander to the nasty little revenge fantasies of male white middle-managers. He’s not averse to spicing his novels up with a hefty pinch of racism (the ‘Fu Manchu’ in a three-piece suit Japan bashing in _Rising Sun_) or sexism (in the rather revolting Disclosure). All in all, it’s rather surprising that Caltech should have asked him to deliver a prestigious lecture. The content and tone of that lecture, however, aren’t surprising at all. The speech – which argues that global warming is pseudo-science – is as specious a bit of argumentation as I’ve seen in a while.

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I’ve been meaning to blog this ever since I read about it a few days ago on Marginal Revolution; it’s one of the neatest ideas that I’ve seen in a while. Given endemic shortages in the availability of some vaccines (viz. flu shots this year), how should one allocate shots so as to prevent the spread of the disease in the general population? Tyler Cowen points to an article by Reuven Cohen, Shlomo Havlin, and Daniel ben-Avraham that suggests how best to do this. It’s fairly well established that some individuals are a lot more likely to spread viruses than others; these ‘super spreaders’ are exceptionally gregarious people, who have a wide and varied circle of friends with whom they share time, conversation, and unpleasant infections. This means that virus diffusion can be modelled nicely using scale free networks with power law distributions of linkages. Some individuals are much more ‘connected’ than others, and these highly connected individuals are much more likely to be the vectors of contagion. If you can vaccinate these individuals, who are the ‘hubs’ of the network, you can do an awful lot to limit the spread of the disease. The problem is that it’s often hard to figure out who the hubs are. Cohen, Havlin and ben-Avraham have figured out a very clever way of doing this. You randomly sample the population, and ask each person who you sample to nominate one of their acquaintances. You then vaccinate _not_ the initial person who has been sampled, but instead their acquaintance. Because ‘super spreaders’ are likely to know far more people than the average member of the population, they will be heavily over-represented among the ‘acquaintances’ – and thus will be far more likely to be vaccinated. According to Cohen, Havlin and ben-Avraham’s model, you may be able completely to halt the spread of the disease by sampling some 20% of the population, and then vaccinating their acquaintances. This is very clever indeed – insights into the topology of social networks can be used to stop the spread of viruses. It goes to show that the study of power-law distributions may have more uses than securing your bragging rights in the blogosphere.

The Obsessive-Compulsive Foundation invites you to apply for their latest round of grants. Once you have satisfied the 27-point checklist for the application, you must send “one (1) original and ten copies (10) for review by Friday, January 30, 2004.” Do not keep calling to ask whether your application has been received.

I’m sorry. I’ll have to make a donation to them now or something.

Words fail.

Kevin Drum updates the score in the ongoing debate between Mann, Bradley and Hughes (climate scientists) and McIntyre and McKitrick (a couple of economists). The latter claim to have re-analyzed data from a famous paper of the former’s on global warming and found numerous errors that, when corrected, make the results go away. The climatologists have responded vigorously, saying that their critics have botched the job. Both sides are preparing further responses at the moment, so the issue is on hold.

That, however, hasn’t stopped Iain Murray from writing a quite inflammatory article in the NRO about all of this. The article tries to stamp the whole issue with his preferred spin:

bq. The whole affair bears strong resemblance to the recent Bellesiles controversy. Emory University historian Michael Bellesiles won a Bancroft Prize for his argument that gun ownership in early America was not widespread. It took an amateur historian, Clayton Cramer, to point out that this claim could not be substantiated on the basis of actual gun-ownership records. Eventually, an Emory University investigation strongly criticized Bellesiles, and the Bancroft Prize was withdrawn.

Given what we know about the present case, this is an indefensible comparison.

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On the one hand, Bruce Sterling waxes lyrical about the weirdness of dark matter in WIRED this month. On the other, Jacques Distler links to the rather more skeptical (and funnier) Dark Matter Flowchart. We blog; you decide.

Kevin Drum is keeping score in an argument about data on global warming. “M&M” (don’t ask me, I’m only reporting this) re-analyzed data for a famous graph and claimed to find serious errors. Now, Kevin says

bq. Somebody — it’s not entirely clear who — exported the original raw data to Excel but somehow exported 159 columns of data into a 112-column spreadsheet. M&M failed to compare the spreadsheet to the original data and thus produced a “correction” that was riddled with errors.

Here’s something you can try at home: Walk up to a statistician, shake their hand and say “When I reanalyzed your data using Microsoft Excel, I found numerous errors.” Stand well back. Wait.

It’s all the worse, really, given that one of the best pieces of software for statistical computing is available for free. In fairness to these guys, though (and in response to a comment below from Kevin), I should say that data management is an often error-prone business that I’ve been bitten by myself. It’d be tough on them if an otherwise well-conducted reanalysis got tripped up because they used an incorrect version of the dataset.

Via the very interesting blog of Dr Anthony Cox , I see that Gerd Gigerenzer has a paper on risk in the British Medical Journal. Doctors, it seems, are alarmingly ignorant about statistics:

bq. The science fiction writer H G Wells predicted that in modern technological societies statistical thinking will one day be as necessary for efficient citizenship as the ability to read and write. How far have we got, a hundred or so years later? A glance at the literature shows a shocking lack of statistical understanding of the outcomes of modern technologies, from standard screening tests for HIV infection to DNA evidence. For instance, doctors with an average of 14 years of professional experience were asked to imagine using the Haemoccult test to screen for colorectal cancer. The prevalence of cancer was 0.3%, the sensitivity of the test was 50%, and the false positive rate was 3%. The doctors were asked: what is the probability that someone who tests positive actually has colorectal cancer? The correct answer is about 5%. However, the doctors’ answers ranged from 1% to 99%, with about half of them estimating the probability as 50% (the sensitivity) or 47% (sensitivity minus false positive rate). If patients knew about this degree of variability and statistical innumeracy they would be justly alarmed.

There’s been much blogospherical and press comment about the recent report that capuchin monkeys have a built-in sense of fairness. In case anyone missed the story here’s Adam Cohen's summary in the New York Times :

bq. Give a capuchin monkey a cucumber slice, and she will eagerly trade a small pebble for it. But when a second monkey, in an adjoining cage, receives a more-desirable grape for the same pebble, it changes everything. The first monkey will then reject her cucumber, and sometimes throw it out of the cage. Monkeys rarely refuse food, but in this case they appear to be pursuing an even higher value than eating: fairness.

bq. The capuchin monkey study, published last week in Nature, has generated a lot of interest for a scant three-page report buried in the journal’s letters section. There is, certainly, a risk of reading too much into the feeding habits of 10 research monkeys. But in a week when fairness was so evidently on the ropes — from the World Trade Organization meeting in Cancún, which poor nations walked out of in frustration, to the latest issue of Forbes, reporting that the richest 400 Americans are worth $955 billion — the capuchin monkeys offered a glimmer of hope from the primate gene pool.

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According to the NYT, Edward Teller has finally met his antimatter twin.

The Age is running a story today headed Asteroid Heads for Earth. Which sounds fairly scary I guess. The article then says that the best estimate is that it has a 1 in 909,000 chance of hitting the earth. I guess Asteroid might be heading for earth, like you might win the lottery this week was too long to fit above the story.