A scientific visualization of the importance of race

The image below is a phylogram, illustrating the degree of variation in a sequence of mitochondrial DNA. The concept is fairly simple: if two DNA samples are from individuals that are evolutionarily distant from one another, they’ll have accumulated more differences in their mitochondrial DNA, and will be drawn farther apart from one another. If the two individuals are closely related, their DNA will be more similar, and they’ll be drawn closer together. That’s the key thing you need to know to understand what’s going on.

There are other, more complicated analyses going on in the figure, too: the branching pattern is determined by analyzing subsets of shared sequences, and it takes a fair bit of computing power to put the full picture together. You’ll just have to trust me on that one, but all you need to know is that the branches are objectively calculated, and that the distances between the tips of the branches and their last branching point tell you something about the degree of genetic disparity in the group.

Unrooted phylogram of mitochondrial DNA sequences. Gagneux P1, Wills C, Gerloff U, Tautz D, Morin PA, Boesch C, Fruth B, Hohmann G, Ryder OA, Woodruff DS. (1999) Mitochondrial sequences show diverse evolutionary histories of African hominoids. Proc Natl Acad Sci USA 96(9):5077-82.

Unrooted phylogram of mitochondrial DNA sequences.

Gagneux P1, Wills C, Gerloff U, Tautz D, Morin PA, Boesch C, Fruth B, Hohmann G, Ryder OA, Woodruff DS. (1999) Mitochondrial sequences show diverse evolutionary histories of African hominoids. Proc Natl Acad Sci USA 96(9):5077-82.

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Stem cell treatment of spinal cord injuries

I have to admit that my first response to these reports out of Britain that stem cells had been successfully used to repair a complete spinal cord transection was skepticism — incredulity even. They’re reporting that a man with a completely severed spinal cord at level T10-T11 is able to walk again! The Guardian gushes! The Daily Mail gets in the act (always a bad sign)! When I read that the patient had an 8mm gap in his spinal cord that had been filling up with scar tissue for the last two years, I was even more doubtful: under the best of conditions, it was unlikely that you’d get substantial connectivity across that distance.

So I read the paper. I’m less skeptical now, for a couple of reasons. They actually did this experiment on 3 people, and all showed degrees of improvement, although the newspapers are all focusing on just the one who had the greatest change. The gradual changes are all documented thoroughly and believably. And, sad to say, the improvements in the man’s motor and sensory ability are more limited and more realistic than most of the accounts would have you think.

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What, this is a thing?

A paper that made extravagant weight loss claims for green coffee beans has been retracted. This study had been touted by Dr Oz, of course — no fraud is to ludicrous for him — and rebutted by Scott Gavura, and I’m generally suspicious of any dietary supplement that promises weight loss without reducing calories or increasing exercise. But there’s one bit that surprised me. The study was done in India by a guy named Mysore Nagendran, and it was sponsored by Applied Food Sciences, Inc. (AFS), the company trying to exploit this Miracle Weight Loss Supplement. They couldn’t get it published, so…

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The ‘evidence from comic book’ argument against evolution

Well, he did it: the Digital Cuttlefish found a novel argument against evolution. It has to be seen to be believed — this creationist is claiming that the X-Men disprove the theory of evolution.

Already you should be saying “It’s a comic book and a movie! It’s not real!”, and for a bonus you might point out that the biology of the X-Men franchise is ludicrously awful, and in general, the mass media don’t understand evolution, but let’s give him a chance. Let’s see this argument.

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Jesus Christ, we have an “Ebola Czar”

All right, this is ridiculous. Obama has appointed an Ebola Czar. By the most pessimistic speculations, we might have “as many as two dozen” infected people by November — right now, it’s a tiny handful. But we need an “Ebola Czar”. We had almost 2000 cases of malaria in 2011, do we have a “Malaria Czar”? We have at least 3000 deaths per year from flu — where is our “Flu Czar”?

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Friday Cephalopod: UNFOLLOW

I just learned that the Blogess has “giant squid phobia”.

squidattack

Several people are aware of my severe giant squid phobia and lovingly (?) sent me this video of a giant squid attacking a Greenpeace submarine, and that’s unsettling enough, but WHY IS THERE ANOTHER SQUID BEHIND IT SPITTING OUT FIRE?  Is that a real thing?  Because I was scared enough without adding: “Oh, and also they can shoot a blinding inferno out of their butts like a tentacled, aquatic bonfire.”  It’s like half giant squid and half underwater maritime flame-thrower, and that’s not natural and is a sign that all giant squid are literally demons from the depths of hell.

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