Gary Farber explains our family’s eating habits

Not mine—the weirder and more peculiar the food, the more likely I am to snarf it down—but those of certain other members of the Myers clan whose identities I will abstain from mentioning, lest they decide to add some really interesting ingredients to my next meal. Anyway, it’s an interesting study that explains why some people get queasy at the thought of food “touching”—it’s a common response to fear of contamination. It’s basically documenting the psychological reality of cooties.

Now if only he had provided an explanation for how to overcome it — the prohibition on mixing too many flavors in our meals is constraining the menu too much around here.

Step away from that ladder

We’ve often heard this claim from creationists: “there is no way for genetics to cause an increase in complexity without a designer!”. A recent example has been Michael Egnor’s obtuse caterwauling about it. We, including myself, usually respond in the same way: of course it can. And then we list examples of observations that support the obviously true conclusion that you can get increases in genetic information over time: we talk about gene duplication, gene families, pseudogenes, etc., all well-documented manifestations of natural processes that increase the genetic content of the organism. It happens, it’s clear and simple, get over it, creationists.

Maybe we’ve been missing the point all along, though. The premise of that question from the creationists is what they consider a self-evident fact: that evolution posits a steady increase in complexity from bacteria to Homo sapiens, the deep-rooted idea of the scala natura, a ladder of complexity from simple to complex. Their argument is that the ladder cannot be climbed, and our response is usually, “sure it can, watch!” when perhaps a better answer, one that is even more damaging to their ideology, is that there is no ladder to climb.

That’s a tougher answer to explain, though, and what makes it even more difficult is that there is a long scientific tradition of pretending the ladder is there. Larry Moran has an excellent article on this problem (Alex has a different perspective), and I want to expand on it a little more.

[Read more…]

Ascidian evo-devo

Here are three animals. If you had to classify them on the basis of this superficial glimpse, which two would you guess were most closely related to each other, and which one would be most distant from the others?

i-3c5822c1c21ece64c8664c4ac32d9b63-ascidian.jpg

i-56ee51e328b10451feb168cd9bab0ea5-amphioxus.jpg

i-703ea1f1beca939b01785054c9529b6c-fish_larvae.jpg

On the left is a urochordate, an ascidian, a sessile, filter-feeding blob that is anchored to rocks or pilings and sucks in sea water to extract microorganismal meals. In the middle is a cephalochordate, Amphioxus, also a filter feeder, but capable of free swimming. On the right are some fish larvae. All are members of the chordata, the deuterostomes with notochords. If you’d asked me some years ago, I would have said it’s obvious: vertebrates must be more closely related to the cephalochordates—they have such similar post-cranial anatomies—while the urochordates are the weirdos, the most distant cousins of the group. Recent developments in molecular phylogenies, though, strongly suggest that appearances are deceiving and we vertebrates are more closely related to the urochordates than to the cephalochordates, implying that some interesting evolutionary phenomena must have been going on in the urochordates. We’d expect to see some conservation of developmental mechanisms because of their common ancestry, but the radical reorganization of their morphology suggests that there ought also be some significant divergence at a deep level. That makes the urochordates a particularly interesting group to examine.

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Spare biology from the opinions of conservative economists

Yesterday, the Wall Street Journal ran a piece on their opinion page (yeah, boo, crap so runny and putrid you can’t even get rid of it with a shovel, I know) that claims biologists have been actively inflating species numbers as a cheap ploy to gain better support for conservation efforts. I really can’t rebut that any better than Loren Coleman does here:

What is occurring is a classic theoretical battle between lumpers and splitters, not a fight of conservationists vs non-conservationists, not a war of Greens vs non-Greens, although “Species Inflation May Infect Over-Eager Conservationists” appears eager to convince you of that. The splitters are making their points lately, with more scientific evidence for a diversity of species.

“Species” are not like “dollars”—they are far more fluid, and to the biologist, there is no way to rank the value of a beetle against a monkey. This is a classic case of concepts in one discipline being applied in a grossly inappropriate manner to the concepts of another.

I’ll also add that, while it may not be true of some groups that focus on charismatic furry beasts to win popular support, among the scientists who do the work of taxonomy, I don’t see the individual species being used as the coinage of environmental conservation. I see much more focus on habitat preservation, which is really where the action is at if you want to save species.

Ah, but the WSJ editorial page is more likely the province of baraminologists than credible authorities.

Seed supports Science Fairs

Seed is doing a Good Thing and hosting a site and forum for the Intel International Science and Engineering Fair (when I was growing up, this was better known as the Westinghouse science fair, and it is very prestigious). Some of the projects that come out of that science fair are just plain intimidating—teachers and students might want to browse the fair for ideas, but don’t be discouraged if some of them are a little overwhelming. It probably helps maintain your perspective to notice that Seed has sponsored an amusing gimmick, too, the world’s largest baking soda and vinegar volcano. (I don’t care how big it is, though, it’s not going to win.)

Sperm in action

This is a beautifully done movie, although it does get a bit silly in the end.

One point this brought to mind: have you ever looked at sperm? They’re amazing. We humans do go through a single-celled haploid stage which is the focus of some very intense selection pressure, and humans in their haploid phase possess some impressive abilities. No brains, but the sperm are motile and exhibit seeking behavior. Eggs are also wonderful — they are precisely balanced on the edge of criticality, ready to erupt into a cascade of changes with a single stimulus. It’s easy to dismiss gametes as blobs and slime, but they have all the charm and complexity of bacteria … and I say that completely non-ironically.

(via Street Anatomy)

Physics of the Sandman

James Kakalios gets to use the latest Spider-Man movie as an excuse to explain the physics of granular materials in the New York Times. Good thing they didn’t ask a biologist about Sandman … all I could think about was that there was no way a loose aggregate of coarse sand would be able to mimic the function of the human brain, which is built upon the sub-micron-scale specific organization of diverse molecules. I would be such a wet blanket.

No, wait, I did think of another thing: could you incapacitate Sandman by dumping your cat’s litterbox on him? I’d think he’d go running off to do some emergency particle segregation right away.

I will say that the Sandman special effects were the best part of the movie. The rest — plot, acting, dialogue — eh, not so much.

An encyclopedia of life?

I wish I could be more enthusiastic about the Encyclopedia of Life project. It’s to be an online encyclopedia with a substantive page dedicated each species on the planet, and it’s endorsed by E.O. Wilson, with sponsorship from some of the most prestigious museums around. It’s a fantastic idea that would be incredibly useful.

But then …

The demonstration pages are beautiful, maybe too beautiful. There’s the promise of a colossal amount of information in each one, although at this point all they’ve got are very pretty but nonfunctional images of what the page will look like — but you can see that the content is not trivial and the organization is detailed. I browsed the FAQ to see how they’re going to do it, and it’s awfully vague. “Mashups” of existing databases? Recruiting sources from existing online collections? They were inspired by Wikipedia? (No, please no…if it’s wikified it will be useless as a source of technical information.) I look at the money they’ve got — $12 million — and the number of species they aim to catalog — 1.8 million — and it just doesn’t add up to me. Aren’t they going to burn through that much money in just paying for the emergency room visits for the brawling systematists fighting over the ontological issues?

I don’t mean to sound so negative, since I think it’s an eminently laudable goal, but I get very, very suspicious when I see all the initial efforts loaded towards building a pretty front end while the complicated core of the project is kept out of focus. I’d be more impressed with something like NCBI Entrez, which, while not as attractive as the EOL mockups, at least starts with the complicated business of integrating multiple databases. I want to see unlovely functionality first, before they try to entice me with a pretty face.

(via John Logsdon)