Tonight! On PBS’ Nova! It’s a promising new documentary on human evolution, Becoming Human.
I’m going to try to watch it, but unfortunately, my glasses are broken, and I just got back from an eye exam, so my pupils are dilated and the world is a far too bright blur. I’ll try to see the glowing blobs moving on my TV screen anyway.
Mooney and Kirshenbaum are still crying over the bad reviews their book received. Move on, Chris and Sheril. Obsessing over your reviews and hashing over them endlessly is yet another sign that the book isn’t very good. Let it stand on its own (that is, shakily, ready to topple at a sneeze) and write another, better book.
If they can, that is.
Perhaps you are a scientist. And perhaps you have wondered how badly the popular press could possibly mangle your research. Wonder no more: we have discovered a new maximum.
Behold this research summary in The Daily Galaxy, and be amazed!
It’s about a paper in the ACS Journal of Physical Chemistry B. It’s straightforward physical chemistry using some cool tools to image the formation of double helices of DNA: it’s simply addressing the question of how complementary strands align themselves in solution. It’s physical chemistry, OK? It’s about tiny molecular interactions…until the Daily Galaxy gets ahold of it. Now it’s about how DNA uses telepathy.
DNA has been found to have a bizarre ability to put itself together, even at a distance, when according to known science it shouldn’t be able to. Explanation: None, at least not yet.
Scientists are reporting evidence that contrary to our current beliefs about what is possible, intact double-stranded DNA has the “amazing” ability to recognize similarities in other DNA strands from a distance. Somehow they are able to identify one another, and the tiny bits of genetic material tend to congregate with similar DNA. The recognition of similar sequences in DNA’s chemical subunits, occurs in a way unrecognized by science. There is no known reason why the DNA is able to combine the way it does, and from a current theoretical standpoint this feat should be chemically impossible.
…
In the study, scientists observed the behavior of fluorescently tagged DNA strands placed in water that contained no proteins or other material that could interfere with the experiment. Strands with identical nucleotide sequences were about twice as likely to gather together as DNA strands with different sequences. No one knows how individual DNA strands could possibly be communicating in this way, yet somehow they do. The “telepathic” effect is a source of wonder and amazement for scientists.
Cue the theremins, everyone, and bring on the reanimated corpse of Rod Serling to narrate this sucker. Audience, say “OOOOOoooooOOOOOOOOooOOH!”
Oh, wait. Read the actual paper, first. It turns out that not only are the scientists not mystified, but they provide a reasonable explanation for the phenomenon, and go on to give some alternatives, even. None of them involve molecular telepathy. They actually are amazed at the ability of these molecules to align…at distances of one whole nanometer!
Pay especially careful to the first sentence of the following paragraph. If you are a journalist writing a summary of a paper, claiming that it says no one knows how the two molecules recognize each other, you should probably read more closely a paragraph that begins, “We hypothesize that the origin of this recognition may be as follows.” It’s a clue that an explanation will follow.
We hypothesize that the origin of this recognition may be as follows. In-register alignment of phosphate strands with grooves on opposing DNA minimizes unfavorable electrostatic interactions between the negatively charged phosphates and maximizes favorable interactions of phosphates with bound counterions. DNAs with identical sequences will have the same structure and will stay in register over any juxtaposition length. Nonhomologous DNAs will have uncorrelated sequence-dependent variations in the local pitch that will disrupt the register over large juxtaposition length. The register may be restored at the expense of torsional deformation, but the deformation cost will still make juxtaposition of nonhomologous DNAs unfavorable. The sequence recognition energy, calculated from the corresponding theory is consistent with the observed segregation within the existing uncertainties in the theoretical and experimental parameters. This energy is ˜1 kT under the conditions utilized for the present study, but it is predicted to be significantly amplified, for example, at closer separations, at lower ionic strength, and in the presence of DNA condensing counterions.
So, their preferred explanation is that there are electrostatic interactions between the molecules that favor pairs that fit together well. Not telepathy. As cautious investigators, they also suggest some alternative explanations; perhaps telepathy will appear here? Or maybe elves?
Presently, we cannot exclude other mechanisms for the observed segregation. For instance, sequence-dependent bending of double helices may also lead to homology recognition by affecting the strand-groove register of two DNA molecules in juxtaposition. The juxtaposition of bent, nonhomologous DNAs may also be less energetically favorable under osmotic stress, since it may reduce the packing density of spherulites. In addition, formation of local single-stranded bubbles and base flipping may cause transient cross-hybridization between the molecules, as proposed to explain Mg2+ induced self-assembly of DNA fragments with the same sequence and length. We consider it to be rather unlikely in this instance, since the probability of bubble formation in unstressed linear DNA of the studied length is very small in contrast to the case where topological strain is relieved by bubble formation in small circular DNA molecules. Furthermore, bubble formation would distort the cholesteric order of spherulites and we see no evidence of this in spherulites composed of a single type of DNA molecule.
I’m so disappointed. Telepathy isn’t mentioned once in the whole danged paper, and there aren’t even tiny diaphanous fairies tugging at the molecules. And no, the Intelligent Designer doesn’t appear, either.
Baldwin GS, Brooks NJ, Robson RE, Wynveen A, Goldar A, Leikin S, Seddon JM, Kornyshev AA (2008) DNA Double Helices Recognize Mutual Sequence Homology in a Protein Free Environment. J. Phys. Chem. B 112(4):1060-1064.
The Discovery Channel is having a documentary about Ardipithecus ramidus at 8pm Central time (in about half an hour). I’m planning to set my work aside for a while and fix a bowl of hot soup — it’s cold here, with a snow storm on the way — and see if they actually do it right.
First half hour wasn’t bad: nice overview of the practice of finding old bones, and a good illustration of the fragmentary nature of the fossil. At the same time, though, it’s also doing a good job of showing how they know the pieces of Ardi are from a single individual.
S l o w i n g d o w n. So far this program is taking longer to watch than it took me to read the original papers. It’s got some nicely done bits, but it sure is taking it’s time, and it’s annoyingly repetitive. It’s also got commercials, and the frequency of commercial breaks is steadily increasing.
I thought we Americans were supposed to have short attention spans. How is this sort of drawn out programming supposed to appeal to the average person with a general interest in evolution?
This is a promotional video for CSIRO, the Commonwealth Scientific and Industrial Research Organization. When I meet any Australian scientist in the future, I will be expecting them to break into song.
Well, no, actually, he didn’t. But once again, he’s going to get misquoted by every creationist on the planet, thanks to Newsweek. They have an article about him and his book, and in a nice bold pull quote, here’s what they claim:
Hey, frogs are highly derived amphibians; we certainly aren’t descended from them. Monkeys are closer to us than frogs, but they’re still cousins, not grandparents. Not only does that quote look silly to a creationist, it looks ridiculous to a scientist.
So what did Dawkins actually say? Why, that the whole simplistic imaginary chains of descent that creationists invent are wrong.
The silliest of all these “missing link” challenges are the following…”If people came from monkeys via frogs and fish, then why does the fossil record not contain a ‘fronkey’?”
If you ever wonder why scientists distrust the media, this is a nice clear example.
It’s another negative review of Unscientific America. I think we’re reaching consensus on one thing: the book was awfully light on substance.
This is an excerpt from a letter Richard Feynman wrote in March 1958, back when I was just about exactly one year old and still wearing diapers. He’d been doing some consulting work for the entertainment industry, and wasn’t very happy with their attitude.
The idea that movie people know how to present this stuff, because they are entertainment-wise and the scientists aren’t is wrong. They have no experience in explaining ideas, witness all movies, and I do. I am a successful lecturer in physics for popular audiences. The real entertainment gimmick is the excitement, drama and mystery of the subject matter. People love to learn something, they are “entertained” enormously by being allowed to understand a little bit of something they never understood before. One must have faith in the subject and in people’s interest in it. Otherwise just use a Western to sell telephones! The faith in the value of the subject matter must be sincere and show through clearly. All gimmicks, etc. should be subservient to this. They should help in explaining and describing the subject, and not in entertaining. Entertainment will be an automatic byproduct.
I don’t entirely agree with him — most entertainment isn’t at all didactic — but he’s right that when you are trying to get an informative message across, the gimmicks have to be the garnish, not the main course, and the work you do in developing the medium has to focus on making the message itself interesting.
For instance, the Book of Kells is an artistic wonder, an illuminated manuscript that anyone could spend hours and days staring at, enjoying the script and the little illustrations all over the pages. But those are geegaws that don’t make the content clearer or more palatable — they allow one to appreciate it while ignoring the message (and a good thing, too — it’s just the dull old gospels turned into art). In communicating science, the goal is not to load it up with bells and whistles, but to make the story you’re telling clear and accessible. You don’t want the listener or reader to overlook the message.
Although I have seen a few evil PowerPoint presentations that show the creator doesn’t understand that concept…
David Colquhoun reviews Unscientific America, and pans it on an interesting point:
I think Mooney and Kirshenbaum have it all wrong. They favour corporate communications, which are written by people outside science and which easily become mere PR machines for individuals and institutions.  Such blogs are rarely popular and at their worst they threaten the honesty of science. More and more individual scientists have found that they can write their own blog. It costs next to nothing and you can say what you think. A few clicks and the world can read what you have to say.  Forget corporate communications.  Just do it yourself. It’s fun. And think of the money you’d save for doing science if the PR people were just fired.
I don’t know if it’s quite ‘corporate speak’ they want, but they do seem to want to put gatekeepers in place, and filter the voice of science to remove any rough edges.
