This is not a photo of a single strand of DNA

Researchers have taken a photo of a DNA strand, which is kind of cool, but also confused me a bit. Here it is:

Wait. The link says that this photo reveals the familiar “spiralling corkscrew” of the DNA double helix, but that can’t be right. The familiar B-DNA form has a diameter of 2nm and the helices ought to show a 3.3nm repeat — this photo shows something way too thick and far too tightly wound to be a single strand. Also, every source I’ve found so far reproduces the photo with the scale bar but doesn’t tell us the size of that bar, which is really annoying.

I looked a little further elsewhere (I don’t have access to the journal it was published in, unfortunately) and found a slightly different story:

…at present, the method only works with “cords” of DNA made up of six molecules wrapped around an seventh acting as a core. That’s because the electron energies are high enough to break up a single DNA molecule.

Oops, yeah. That makes more sense. So sorry, you still haven’t seen a photograph of a single double-helical strand of DNA. But at least now you’ve seen many strands of DNA wrapped around a filament.


Here’s a much more detailed critique of the reporting on that paper.

Oh gob, evo psych again?

You may have already heard that Ed Clint, a guy who has been dedicated to bashing Skepchick and Freethoughtblogs for over a year, has cloaked his biases in a pretense of objectivity and written a long critique of one of Rebecca Watson’s talks, accusing her of being a science denialist and anti-science because she so thoroughly ridiculed pop evo psych. The excesses and devious misrepresentations in that post were painful to read, as was the revelation that Clint is throwing away his career by jumping on the evo psych bandwagon in graduate school (I frequently advise students on good disciplines to pursue in grad school; bioinformatics and genomics have a great future ahead of them, as does molecular genetics and development, but evolutionary psychology is one I would steer them well clear of, as a field that has not and will not ever contribute much of substance. The good papers in evo psych are the ones that use the tools of population genetics well and avoid the paleolithic mumbo-jumbo altogether).

Fortunately, Stephanie Zvan has already torn into his ‘analysis’, showing that it’s mostly misplaced and misleading. I’m relieved, because I’m going to be tied up for a while, and I found Clint’s response to be extremely irritating.

One think that particularly rankled is that Clint puts up a pretense of being objective and that his criticisms are nothing personal; bizarrely, he even puts up a photo of himself taken with Rebecca Watson as if that were evidence that he’s not biased against her. What he doesn’t mention is that he’s been sharpening an axe since the “elevatorgate” episode; together with a disgruntled ex-FtB blogger who left in a bizarre huff over not getting enough respect, he founded a competing network (which is fine, of course) which they proceeded to stock almost entirely with writers with an an anti-FtB and strongly anti-Skepchick slant — I’ve had to laugh at the lineup which looks largely drawn from the ranks of the Slymepit, a notorious anti-feminist/anti-Rebecca Watson hate site, and my list of banned commenters. And looking at the people who comment there, again, they seem to be largely driven by hatred of Watson and feminism in general.

Again, that’s fine — we have biases here at FtB, too, in that we tend to be pro-feminist and when we founded it, I specifically told Ed Brayton that we needed to be sure to include more than just old white guys like us — but what isn’t fine is to lie about your motives. Any day, I’ll prefer open antagonism from an avowed enemy than fair and dissembling words from an Iago.

For example, after telling people to avoid insults in the comments, this is what Clint has to say:

Although PZ’s behavior is unfortunate, I would urge a modicum of compassion. I believe he lashes out because he feels so small and vulnerable, and because he is. I can think of few other reasons for such unprovoked barking. He is making a mistake in coming after me. He will be wounded by it. I wish it didn’t have to be this way, and that we could just have a calm chat about it.

Condescending and smarmy, isn’t he? Ick. He won’t call me names, he’ll just call me “small and vulnerable.” Man, I despise that kind of sliminess.

I’ll follow up on Stephanie’s post later this week, when my schedule calms down, and what I intend to do is dig into the substantive flaws in both Clint’s hatchet job and in that awful discipline of evolutionary psychology. Seriously, in the reviews Clint recommended to give the background on what evo psych is, I was appalled — do these people have any understanding of modern evolutionary theory at all? I think the answer is clearly “no.”

I’m back!

I staggered home last night at about 2am, fresh from Eschaton 2012. It was a very good conference from my perspective (and probably everyone else’s, too!). There was a familiar mix of good friends from Freethoughtblogs — Natalie Reed, who was given a well-deserved award from CFI for her social justice work, Hank “Beta Culture” Fox, Ian “Zombie Slayer” Cromwell, Ophelia “God Hates Women” Benson, and me, who bored everyone to tears with a primer on some very basic principles in population genetics (why do these people keep inviting me?). Then there were some familiar big names: Larry Moran, Chris DiCarlo, and Eugenie Scott. And then what I really look forward to: meeting new people who either are, ought to be, or will be big names: Veronica Abbass (why haven’t I been following Canadian Atheist before?), Dear Ania, and of course people like Heina, Eric MacDonald, Udo Schuklenk, Vyckie Garrison, and Jeff Shallit. There were others I missed; it was a surprisingly diverse and ambitious conference with two parallel tracks so you couldn’t see everything. That was a cunning ploy, I think, to whet our appetites for more so we’ll come to the next one. I learned stuff and had good conversations and that’s all I really ask of a conference.

Now, unfortunately, while I’m physically back in Morris for a good long while, I have to warn you that this is the last week of the semester and the chronic distractions of a heavy workload are about to flare into acute intensity: this is the week I have to give and grade the last unit exams of the term, grade term papers, advise worried students on their status in my courses, and do a bit of essential committee work, too, so I’m not going to be able to do much blog writing for a bit, despite positively aching to get a bunch of science and atheism stuff hammered down in words. The blog has to wait a bit longer while I deal with my top priority teaching.

But the end is in sight! These demands on my time (really, I’m looking at staying up much of tonight trying to get a stack of exams graded promptly) will begin to ebb around mid-week, and then finals aren’t that bad — they’re like the last paroxysm before the fever breaks. I shall persevere. You’ll have to bear with my boringness for a bit longer.

Hammy gets it wrong, again

Ken Ham is mad at Bill Nye again, because in the wake of the Rubio nonsense, Nye went on the air to explain why the earth is actually 4½ billion years old. Here’s the clip:

Now here’s where Ken Ham wigs out.

Well, children’s TV host Bill Nye’s understanding of science is worse than I thought. A few days ago, Bill Nye was interviewed on CNN about the age of the earth (this topic was a hot one in America because of headline news after Sen. Marco Rubio was asked a question about what he believed concerning the age of the earth).

Bill Nye in this CNN interview actually equated the age of the earth to the invention of smoke detectors. Hard to believe—but he did!

No, Ham really didn’t understand anything Bill Nye said, and it’s richly ironic to see Ham claiming someone else has a worse understanding of science.

Ionizing smoke detectors use a tiny amount of radiactive material to generate charged ions by their decay; these ions are released into the space in a capacitor, and their movement generates a constant trickle of current. If smoke particles enter the detector, they bind to the ions and block the current; that easily measured decline in current is what triggers the alarm in the detector.

This is a very simple system that depends entirely on our quantitative understanding of radioactivity. If radioactivity didn’t work like we thought it did, your smoke detector would not be very reliable, and for that matter, no one would have thought of using this function to work as a smoke detector.

Bill Nye did not equate the age of the earth to smoke detectors. He used smoke detectors as an example of how scientists have a very thorough understanding of radioactive decay. What he did use as an indicator of the age of the earth was a very brief summary of how rubidium decays into strontium with a half-life of about 48 billion years, allowing us to estimate the age of a sample by measuring the relative amounts of the two elements.

Ham then goes on his usual ignorant tangent of observational vs. historical science (ignore it, it’s rank inanity and I’ve dealt with it before) and challenges Nye to explain the very fact he explained in the video: I’ve highlighted a particularly relevant bit.

I once again challenge Bill Nye to give us one example of how evolution has anything to do with the development of technology and to explain how smoke detectors have anything to do with the age of the earth—when a detector is actually the result of intelligent observational science and the accumulated information about the properties of matter that enabled inventors to build such technology.

Yes, exactly. We have accumulated information about the properties of matter that allow us to build smoke detectors, and that same information rules out the possibility that the earth is 6000 years old. The information contradicts Ham’s claims. But what Ken Ham wants to be able to do is throw out the scientific information that makes his biblical exegesis into nonsense, and keep the bits that allow smoke detectors to work.

You don’t get to do that.

But the smoke detector discussion wasn’t about evolution, anyway. It was about a measurable physical property of the universe, its age, which Ham denies. I wish these guys could get it straight: evolution is about biology, and describes processes in living creatures that occurred on this one planet; physics is describing more general physical properties that are not specific to biology.

Ham is screeching about a debate between Nye and one of his clueless staff people. I do not recommend that Bill Nye take him up on it — as we can see, the Answers in Genesis folk don’t understand anything, don’t pay attention to what other people say, and don’t learn anything, so a debate would just be an opportunity for a creationist to preach from a podium with a credible and credentialed real science educator right next to them. Not a good idea.