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Archive for June, 2008

This is also a pretty cool video about life expectancy, birth rates, per-capita income, and first world/third world comparisons. (Uh, it’s cooler than it sounds, and he’s an interesting speaker.)

Hans Rosling: “Debunking third-world myths with the best stats you’ve ever seen” (20 minutes long):
Vodpod videos no longer available. from www.ted.com

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I’d like to be able to say that I scooped PZ Myers on this video, but I didn’t. But, it’s still cool.

David Gallo shows Underwater Astonishments (5 minutes long):
Vodpod videos no longer available. from www.ted.com

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This is a rather sad story: people have killed albinos in Tanzania because they believe albinos are the result of a curse, and that their bodies have magical properties. In the past, I’ve heard of magical thinking being the basis for killing all kinds of wild animals (gorillas, rhinos, and other endangered animals) based on a belief that their body parts can be used in magical potions, but never human beings. How frightening it must be for albinos.

[BBC] Tanzania’s Albino Society has accused the government of turning a blind eye to the killing of albinos, after four deaths in the past three months.

An albino spokesman said there was a belief that the condition was the result of a curse put on the family.

Some witch-doctors also say they can use albino body parts in a potion to make people rich.

A teacher in the northern town of Arusha has been arrested for killing his own child, who was albino.

(Full story available here / December 2007)

According to a more recent story (April 2008), the government has begun doing a crackdown on attacks against Albinos, but the numbers aren’t comforting:

Twenty people with albinism have been murdered in the past year in Tanzania, where there is a widespread belief that the condition is the result of a curse.

Our correspondent says that in some parts of the country, people think albinos bring bad luck to the whole community.

While there have not yet been any prosecutions regarding the recent spate of murders, 172 were last month arrested in connection to the cases – 71 of whom said they had been told by witch doctors to bring them albino body parts.

And, as if that wasn’t bad enough, in Zimbabwe, albinos have other problems fueled by superstition – the threat of rape by HIV-infected men:

But now, besides being treated like lepers, albino women have increasingly been the victims of rape – a practice fuelled by myths that if an HIV infected man sleeps with an albino woman, he will be cured.

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Leduc’s weird tale began on May 30, when she dropped young Victoria off for class at Terry Fox Elementary and headed in to work, only to receive a frantic phone call from the school telling her it was urgent she come back right away.

The frightened mother rushed back to the campus and was stunned by what she heard – the principal, vice-principal and her daughter’s teacher were all waiting for her in the office, telling her they’d received allegations that Victoria had been the victim of sexual abuse – and that the CAS had been notified.

How did they come by such startling knowledge? Leduc was incredulous as they poured out their story.

“The teacher looked and me and said: ‘We have to tell you something. The educational assistant who works with Victoria went to see a psychic last night, and the psychic asked the educational assistant at that particular time if she works with a little girl by the name of “V.” And she said ‘yes, I do.’ And she said, ‘well, you need to know that that child is being sexually abused by a man between the ages of 23 and 26.'”

Victoria, who is non-verbal, had also been exhibiting sexualized behaviour in class, actions which are known to be typical of autistic behavior.

But things got worse when school officials used the “evidence” and accepted the completely unsubstantiated word of the seer by reporting the case to Children’s Aid, which promptly opened a file on the family.

“They reported me to Children’s Aid,” Leduc declares, still disbelieving. “Based on a psychic!”

The mom, who is divorced and has a new fiancé, adamantly denied the charges, noting her daughter was never exposed to anyone of that age. And fortunately she had proof. The mother was long dissatisfied with the treatment her daughter had received at the school, after they had allegedly lost her on several occasions.

As a result, the already cash strapped mom had spent a considerable sum of money to not only have her child equipped with a GPS unit, but one that provided audio records of everything that was going on around her.

So she had non-stop taped proof that nothing untoward had ever happened to her daughter, and was aghast that the situation had gone this far. But under the Child and Family Services Act, anyone who works with children and has reasonable grounds to suspect a youngster is being harmed, must report it immediately – and the CAS has an obligation to follow up.

And so a case worker came to the Leduc home to discuss the allegations of sexual misconduct, only to admit there wasn’t a shred of evidence that anything had ever happened at all. They labelled Leduc a “diligent” mother doing the best she could for her child under difficult circumstances, closed the file and left, calling the report “ridiculous.”

(Source)

It’s a good thing the mother had the GPS/audio-recording device. Otherwise, she might’ve gotten sucked in, too – and been distressed about the (fictional) terrible things happening to her daughter.

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A lot of creationists believe that mutations can’t “create information”, they can only destroy it. They like to imagine making random changes to a book – it always ends up making random gibberish – thus, random mutations must do the same thing to the genome, right? Wrong. This misconception is so widespread, I thought I’d go ahead and prove that random mutations can create information.

First, I should say that creationists use a rather subjective definition of information. They aren’t talking about Shannon information or anything like that. Instead, “genetic information” is synonymous with “useful genetic sequences”. It’s not something that can be measured, and it’s highly contextual (a useful sequence in one creature might be completely useless in another creature). Despite the subjectiveness of the definition, we can all agree that genes do something useful in the body, that the genome contains a high concentration of useful genetic sequences (in comparison to say, a randomly generated DNA sequence).

So, let’s use the creationist’s definition of genetic information. Let’s say that we have a small sequence of DNA consisting of 90 nucleotides. We’ll call this Sequence A.

Let’s also say that we have another DNA sequence which is identical to Sequence A except that it is different in just one codon. We’ll call this Sequence B. There are three possibilities for the Sequence B: it does something better, equally well, or worse (perhaps not at all) than the Sequence A. (In creationist language, it contains more information, the same information, or less information than Sequence A.)

Now, if a point mutation happens to occur to Sequence A or Sequence B, it will alter it at one codon. Given the number of nucleotides (90) and the fact that there are three possible other codons at each location, the odds of a point-mutation turning Sequence A will turn it into Sequence B is 1 in 270. Similarly, the odds that a point-mutation will turn Sequence B into Sequence A is 1 in 270. So, both sequences can be converted into each other. But, we said earlier, that we don’t know if Sequence B is more useful, equally useful, or less useful to the creature than Sequence A. If Sequence B is more useful than Sequence A, then the mutation changing Sequence A into Sequence B (1 in 270 odds) is an increase in information. If Sequence B is less useful than Sequence A, then the mutation changing Sequence B into Sequence A (1 in 270 odds) is an increase in information. Thus, if A > B or A < B, we can prove that information can increase.

Once the mutation exists, natural selection either drives it into extinction – if harmful, or causes it to proliferate in the species – if useful.

Counterargument 1: A creationist once counterargued that, since the sequences can be inter-converted, that both sequences must have the same amount of information. Because I haven’t even told you what the actual sequences are, then his “equal information” argument must be true for all possible sequences A and B. In order for his argument to work, this means all possible 90 nucleotide sequences must have the exact same amount of information. (This is because it’s possible to convert any sequence X into any other sequence Y via a finite number of single-codon changes. If each single-codon change results in 0 information change, then all sequences X and Y have equal information, no matter how different they are.) Since there is nothing special about 90 nucleotides – he has to argue the absurd position that all possible sequences of N nucleotides contain the same amount of information. And since insertion and deletion mutations can alter the number of nucleotides, then (by his logic) all DNA sequences containing any number of nucleotides must contain the same amount of information.

Counterargument 2: “But evolution can’t explain complex systems”. I typically interpret this response as “I don’t want to admit you’re right. So, I’ll bring up a related – but different – topic.” This example does show an increase in information, and there’s not much sense in moving-on to other topics if creationists aren’t willing to admit it when it’s made obvious. Besides, if they can’t admit that mutations can produce “new information” when it’s made plain, then talking about other topics are unlikely to be fruitful.

Counterargument 3: “The second law of thermodynamics prevents an increase of information.” First of all, creationists are misapplying the second law of thermodynamics to make it say something that it doesn’t say. Second, what if it were really true that mutations can’t accidentally produce an increase in information? In order for mutations to never create information, you have to accept a whole bunch of absurd conclusions. First of all, the random mutation would have to understand how that gene functions in order to avoid causing an accidental improvement. They have to argue that a mutation can turn a fully functional gene into a weaker version, but once that weaker version exists, mutations will explicitly avoid any change that would convert it back to it’s original form (in spite of the mathematics). Additionally, it would have to understand how that gene works within each specific creature. Because the sequences are context specific (i.e. depending on the creature’s biology), then it’s possible that Sequence A will function better in Creature A, but Sequence B functions better in Creature B. Do mutations “know” to allow and avoid the specific mutations based on creature type? In Creature A, a mutation can turn Sequence A into Sequence B, but never the Sequence B into Sequence A? And vice-versa in Creature B? Of course not. The sequences and mutations are completely blind about what effects the mutations have, and that means that they can accidentally increase the information.

Second, if Sequence A contained more information than Sequence B, then we could take a million copies of Sequence B, expose them to mutagens until each of them had a single point-mutation, then look at those million mutated copies, and (against all laws of probability) none of them would have been turned into Sequence A. If true, it would allow scientists to accurately produce a hierarchy of genetic sequences sorted from “contains more information” to “contains less information”, defying all logic about how the universe works. If true, it would allow scientists to perform all kinds of miracles – because the mutation would explicitly avoid any increase in information – biological or otherwise. You could learn secret information by looking at what sequences it seems to avoid. Take a billion copies of the human hemoglobin gene, and expose it to a mutagen. Any sequences which never appear in the results would be stronger versions of the hemoglobin gene. Of course, the universe doesn’t work that way.

Counterargument 4: “Your example shows an increase in information in one case out of 270. What about the other 269 cases? If some of them are negative, then the average result is a decrease in information.” That’s true. The average case probably is a decrease in information. But, that’s where natural selection steps in. Natural selection drives the negative mutations out of the gene pool (because the creatures that have the negative mutation are less likely to survive or reproduce than the rest of the population). Natural selection also promotes the spread of positive mutations throughout the gene pool. This gives the (rare) positive mutations a huge boost over the (more common) negative mutations.

Counterargument 5: If mutations can be positive, then why do our bodies have mechanisms to prevent and reverse mutations? Mutations are a mixed-bag. Some are positive, some are neutral, and some are negative. There a probably a lot more negative mutations than positive ones. This means it’s critical to keep the number of mutations low – so that positive and negative mutations can be sorted by natural selection. Here’s an example: let’s say that you are playing a game. You pickup a random card from a deck, and whenever you get an Ace, you win. Whenever you pickup an 6 or less, you automatically lose. All other cards are a draw. Clearly, the game is stacked against you – 1 out of every 13 cards is a winner, but 5 out every 13 cards is a loser. Except there is one additional rule: you can bet between $1 and $10 on each round, and you get to decide how much to bet after you see your card. Of course, whenever you pull an Ace (1 in 13 odds), you bet $10. Whenever you pickup a 6 or less (5 in 13 odds), you bet $1. (This resembles the way natural selection magnifies the value of positive mutations, and minimizes the damage of negative mutations to the gene pool.) The result is that the game is now in your favor. Now, imagine if the rules were changed slightly: instead of picking up one card, you have to pickup two cards at a the same time (i.e. an increase in the number of mutations). In a few cases, you’ll pickup two Aces or an Ace + 7 or higher, and you win $10. But, in other cases, you’ll pickup an Ace and a 6 or less (resulting in a loss). In this example, the result of this change is that players win 15% more frequently, but get a losing hand 60% more frequently – because the losing cards are more likely to show up. If we pickup three or four cards at the same time, it gets even worse. When we calculate the average winnings per hand:

Single-card rules: (0.077*$10) – (0.385*$1) = +$0.385 per hand
Two-card rules: (0.089*$10) – (0.621*$1) = +$0.269 per hand
Three-card rules: (0.077*$10) – (0.767*$1) = +$0.003 per hand
Four-card rules: (0.059*$10) – (0.856*$1) = -$0.263 per hand

The same thing with mutations: high rates of mutation means more positive mutations, but it also means more negative mutations. If you happen to get a positive mutation and negative mutation at the same time, then the creature might be dead – preventing the spread of that one positive mutation. In the end, the best solution is to keep the number of mutations low – and that makes anti-mutation mechanisms useful.

Saying “creatures have mechanisms to prevent mutations – therefore mutations must always be bad” is a little bit like saying “animals have mechanisms to prevent swallowing too much food at one time – therefore food must be bad”.

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I went and saw The Happening tonight. It was okay. There were a few parts where the writing was so bad, I couldn’t help but laugh. Early in the movie, Mark Walberg’s character (a science teacher named Elliot Moore) asks his students why bees are mysteriously disappearing. One student answers that plants are evolving against bees, another answers that climate change is causing it. Finally, another student replies, “it’s an act of nature that we can’t understand”. Surprisingly, the teacher agrees with this answer. It was laughably bad that a science teacher would accept such an anti-science answer. Before doing adequate study, you should just throw up your hands and say, “We can’t know. It’s mysterious, and always will be”?

Later in the movie, plants are giving off a toxin that causes people to kill themselves. Roughly the entire population of the Northeast United States commits suicide. Then we have Elliot Moore (and another science-y talking-head on the news) making the same claim about this bizarre outbreak: “it’s an act of nature that we can’t understand”. That’s right: plants created a toxin that killed some 50 million people, and their response is to throw up their hands with no scientific study whatsoever, and declare that it’s mysterious and always will be. Huh? It’s a response right out of the Dark Ages.

Well, over at io9, there’s a review of the movie that claims The Happening is all about Intelligent Design and religious faith:

Avowed Christian Shyamalan told us that The Happening is really about religious faith, and explained that he chose Mark Wahlberg to play science teacher Elliot Moore because of the actor’s intense belief in Jesus.

Personally, I think the reviewer is running off the deep-end by claiming it has something to do with Intelligent Design. But in an earlier article, Shyamalan explains the religious connection:

Night was inspired by reading Albert Einstein’s biography and discovering Einstein had rejected religion at first, until eventually he saw “the hand of God” in the gaps between scientific explanations. In The Happening, Shyamalan tries to recreate this surrender to faith by saying, sometimes you just can’t explain it when shit happens… Added Shyamalan, “There are limits to rational thought.”

Sorry, but I don’t really see the connection – even after he says it’s there. In fact, if this is a pro-religious faith movie, it fails miserably. Instead, it does the opposite for me: it elucidates the problems of Intelligent Design and religious faith quite well — the main characters were just throwing up their hands, declaring it to be mysterious and unknowable without the least bit of research. Maybe Shyamalan would like to tell everyone that all diseases are mysterious and we can never them figure them out, either. Like I said, it was a response right out of the Dark Ages, and certainly an embarrassing position for any self-respecting science teacher to take.

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Part 2 available here.

I would add that Christianity and Islam make many of these claims. Christians claim that Jesus fulfilled prophecies of the Old Testament. (I’ve dealt with these in the past, and find them unpersuasive.) I’ve also seen a number of Islamic claims that the Koran predicted scientific discoveries. For example, they claim that the Koran predicted the expanding universe:

“And the sky we built it with might and We cause the ‘expansion’ of it” (Koran 51:47) or “We created the heavens with Our strength and power, and constantly expand them.” (Koran 51:47)

Of course, “expansion” doesn’t mean that the sky is expanding, but the word “expansion” can be used to describe an expanse. And the second version was, apparently, a bit of creative translation by people eager to make it anticipate the science. Other translations of the same verse:

“We built the heaven with Our might, giving it a vast expanse, and stretched the earth beneath it” (Source)
“And the heaven, We raised it high with power, and most surely We are the makers of things ample.” (Source)
“And the Heaven–with our hands have we built it up, and given it its expanse;” (Source)
“We have built the heaven with might, and We it is Who make the vast extent (thereof).” (Source)

Just goes to show what power translators have when they know what scientific discovery they want it to predict. For what I’ve seen, it seems that the “Koran predicted science” idea is a popular meme among Muslim evangelists.

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