Axis formation in spider embryos

Blogging on Peer-Reviewed Research

Some of you may have never seen an arthropod embryo (or any embryo, for that matter). You’re missing something: embryos are gorgeous and dynamic and just all around wonderful, so let’s correct that lack. Here are two photographs of an insect and a spider embryo. The one on the left is a grasshopper, Schistocerca nitens at about a third of the way through development; the one on the right is Achaearanea tepidariorum. Both are lying on their backs, or dorsal side, with their legs wiggling up towards you.

i-6ddf13f64ed1f0ee13f5355c7b0650d9-hopper_embryo.jpgi-a1059781f7a09203cbfa43e1e71e4c70-spider_embryo.jpg

There are differences in the photographic technique — one is an SEM, the other is a DAPI-stained fluorescence photograph — and the spider embryo has had yolk removed and been flattened (it’s usually curled backward to wrap around a ball of yolk), and you can probably see the expected difference in limb number, but the cool thing is that they look so much alike. The affinities in the body plans just leap out at you. (You may also notice that it doesn’t seem to resemble a certain other rendition of spider development).

[Read more…]

We won’t have Dianne Mandernach to kick around anymore

Our Minnesota Health Commissioner, a Republican appointee who was supported by our Republican governor through a number of startlingly clueless incidents, has finally resigned. Here’s a short summary of her career:

This summer, Mandernach was criticized over her suppression of a state study about 35 cancer deaths related to taconite mining on Minnesota’s Iron Range.

In 2004, her credibility suffered when a website posting by the department suggested that abortion might have a role in breast cancer. Critics denounced those claims as junk science, and the wording was removed from the website.

So she hid real cancer risks and promoted fake cancer risks. She got it wrong coming and going! How could that be? Could it be…ignorance and arrogance?

Marty said his misgivings began about a year after her appointment, when Mandernach was forced to remove the wording on the website that claimed a link between abortion and breast cancer.

“She told me it was her judgment to override all of the scientific information at the time,” Marty said.

What were the qualifications of this paragon to override scientific evidence? She was “a former nun and teacher, was chief executive of the Mercy Hospital & Health Care Center in Moose Lake”. Doesn’t that fill you with confidence?

I think I know what’s going to be featured in Expelled

I’ve been trying to recollect what horrible thing I said in that interview with that film crew … what juicy, ghastly, evil comment I might have made that will be plucked out and impaled on a stick and waved to the audience to inflame them. It’s a waste of time, of course — I tend to be far too mellow in person, despite occasional brief declamations that religion is crap, and they’re going to have to strain a bit to find anything sufficiently inciteful.

And then I remembered — the interviewer was mildly obsessed with one thing that he brought up several times. It was a quote from this interview, otherwise most memorable for the way that kook John A. Davison turned the comment thread into a maelstrom of inanity.

[Read more…]

Another year, another collection of dreck from AiG

Last year, Answers in Genesis ran an essay contest for young creationists — the prize was a $50,000 scholarship to Liberty University (second prize must have been a $100,000 scholarship). Well, they ran it again this year, and the ‘winners’ have been announced, and a sorry lot of recitations of bogus creationist talking points they are. Evolution turns people into immoral killers! Darwinism leads people to abortion and Hitler! Cells are full of little machines created by Jesus! It’s really sad to see young people led down the path of stupidity like that.

If you really must read them, you can … but Zeno has read and summarized them so you don’t have to. Maybe I should read them more myself — since a new semester is beginning next week, they’d recalibrate my brain to have lower expectations, and all of my freshmen students will be brilliant, literate geniuses by comparison.

Nah, I don’t have to. They already are, and I know it.

Atheist fires a shot across scientists’ bows

Sam Harris has a letter in Nature today, urging scientists to unite against religion — even the moderate religion that so many are willing to support.

But here is Collins on how he, as a scientist, finally became convinced of the divinity of Jesus Christ: “On a beautiful fall day, as I was hiking in the Cascade Mountains… the majesty and beauty of God’s creation overwhelmed my resistance. As I rounded a corner and saw a beautiful and unexpected frozen waterfall, hundreds of feet high, I knew the search was over. The next morning, I knelt in the dewy grass as the sun rose and surrendered to Jesus Christ.”

What does the “mode of thought” displayed by Collins have in common with science? The Language of God should have sparked gasping outrage from the editors at Nature. Instead, they deemed Collins’s efforts “moving” and “laudable”, commending him for building a “bridge across the social and intellectual divide that exists between most of US academia and the so-called heartlands.”

He seems to feel the same way about Collins that I do.

Clearly, bloggers need to take over science journalism

Aaargh. When will the media learn? National Geographic is running this ridiculous headline right now: New Fossil Ape May Shatter Human Evolution Theory, in which the reporter claims a discovery of some teeth could “demolish a working theory of human evolution.” It’s not true. Where is this nonsense coming from?

I read the article. It’s titled “A new species of great ape from the late Miocene epoch in Ethiopia.” The exciting news is that the “combined evidence suggests that Chororapithecus may be a basal member of the gorilla clade, and that the latter exhibited some amount of adaptive and phyletic diversity at around 10-11 Myr ago.” It concludes with a suggestion that we need to do more research in sediments appropriate to Miocene apes. There aren’t an exploding paradigms or revolutions suggested.

I read the associated news article in Nature. It’s titled “Oldest gorilla ages our joint ancestor.” It says that this discovery pushes back the time of divergence of the gorilla lineage from our own. This is just ordinary science.

Now read the blogs — they’re doing a much better job of evaluating this work than the traditional media. For one thing, they’re actually looking at it critically. Afarensis points out that these are only a few teeth, and it’s awfully thin grounds for a substantial revision of the timeline. John Hawks makes a similar point, but also highlights the fact that there is an unresolved problem — we need to reconcile paleontological and molecular dates. Even John Wilkins, a “mere” philosopher, weighs in sensibly that teeth are plastic characters in phylogeny, and deplores this peculiar media habit of taking a recalibration of a historical detail as a major reformulation of theory. All these discussions are sober and interested and most important of all, accurate.

The lesson is clear: when you see some wild and crazy claim of scientific revolutions and the demolition of long-held theories, go immediately to the science blogs for some clear-eyed sanity and informed evaluation from experts.