In tomorrow’s New York Times, I have an article about how new species evolve. It describes new research into how a population can split into two species. The idea that species can evolve when populations get geographically isolated is well-supported by evidence, but the idea that individuals living side by side can split apart (called sympatric speciation) has sparked more controversy. The late biologist Ernst Mayr was the lead champion of the geographic isolation mechanism, and he was always skeptical of claims of sympatric speciation. But, as he said in this 2001 interview, he was skeptical not so much of sympatric speciation itself, but of the particular cases that were made for it. That’s continued to be the sticking point for a lot of evolutionary biologists. Two new cases–one concerning palm trees, the other fish–have impressed the critics I spoke to. I just wonder what Mayr would have said.

You and an oak tree have something in common: you’re both big. Unlike viruses and bacteria, you and an oak tree are both made up of trillions of cells. There’s something else you and an oak tree have in common: you both began as an individual cell, which then divided again and again, its daughter cells differentiating along the way to produce tissues. In your case, they turned into bone, muscle, liver, and such. In the oak’s case, the cells became bark, leaf, root.

You and an oak tree have a third thing in common: you evolved from single-celled ancestors. By analyzing DNA from a wide range of species, scientists have been closing in on the closest microbe relatives of plants and animals in recent years. For animals, the evidence is pointing to a protozoan called a choanoflagellate. For plants, a few lineages of green algae are emerging as the closest relatives.

Once scientists find out who these relatives are, they can then tackle the puzzle of how big things evolved from small ones. How did multicellular animals evolve the genes they use to develop from ancestors that didn’t grow bodies? Part of the answer, it turns out, is that at least some of the genes were already there in the single-celled ancestors.

A new study takes a look at the evolution of plants. Land plants evolved from algae over 475 million years ago according to the fossil record. The earliest plants resembled today’s liverworts and mosses–which, not coincidentally, belong to the oldest branching of living plants. While moss and oaks may not seem to have much in common, they share a very important trait. They each produce cells that can divide asymmetrically, forming a shoot that can rise upward. This organ, known as a meristem, allows land plants to be more than a sheet of slimy algae. They can be three-dimensional. Becoming 3-D brought many benefits to early land plants, letting them rise up out of water, for example, while reducing their surface area-to-volume ration to cut down on their water loss.

In 2003 French scientists reported the discovery of body-building genes in moss. When moss develop buds, their cells use six related genes, which the scientists named BIP1 through BIP6. None of the BIP genes were active in moss cells before budding, and when BIP genes are knocked out, moss cells can’t form three-dimensional structures.

Canadian researchers have now looked for similar BIP genes in other species. They’ve found them in land plants, such as corn and cress, which supports the idea that these genes have played a crucial role in the growth of land plants since they first became three-dimensional. The scientists don’t find the genes outside the land plants–except for a species of green algae, Mesostigma viride. It turns out that Mesostigma is also among the closest relatives of land plants. (The paper is in press at Molecular Biology and Evolution; you can get the pdf for free on the lead author’s publications page.)

Mesostigma is a humble little alga, and so it obviously doesn’t use its BIP genes to grow into towering trees. Exactly what it does with the genes remains to be discovered–after all, the genes themselves have only just been discovered. But the most logical way to interpret the new findings is that the single-celled ancestors of land plants had BIP genes long before they co-opted them for growing 3-D.

The scientists point out that both Mesostigma and its land plant relatives have many copies of BIP. That’s a common pattern in evolution. Genes get accidentally duplicated, and natural selection sometimes favors having lots of extra copies around. As green algae first shifted from the ocean to fresh water, duplicated BIP genes may have been favored to help them adapt to their new home. Later, land plants evolved in one lineage of these green algae, and they co-opted one or more BIP genes to grow three-dimensionally. Land plants evolved still more copies of BIP for growth, and then in later lineages, some of these genes were co-opted yet again for new uses.

This pattern of duplication and co-option turns up again and again, from microbes to humans. It even turns up in another small-to-big transition: the evolution of animals. Among the tools animals use to grow multicellular bodies, they need communications equipment so that neighboring cells can talk to one another and coordinate their growth. Choanoflagellates, the closest single-celled ancestors to animals, have the same genes that animals use for this cross-talk. In other words, the single-celled ancestors of animals already had some of the equipment their descendants would use to build big bodies.

Just another item to add to the list of things you and an oak tree have in common.

Update 2/20 3 pm: changed 475 years to 475 million years. What’s a million between friends? (Thanks to Gal Haspel.)

Randy Olson, director of the movie, Flock of Dodos has sent in some thoughts regarding the ongoing conversation here about his movie. A lot of commenters were offering opinions on how evolutionary biologists should communicate with the rest of us. I thought I’d publish his entire comment here in a post of its own. (Added note: Randy is fielding questions and opinions in the comment thread if you want to join in.)

Hi – A big thanks to Carl for such a nice write up about the screening (which was a huge amount of fun). At each of the panel discussions for the first round of screenings of “Flock of Dodos” people asked, “So what can we, as evolutionists, do about this problem?” Here’s a summary of some of my responses.

TEN THINGS EVOLUTIONISTS CAN DO TO IMPROVE COMMUNICATION

(Why is it this list took me all of one minute to outline? Could it be that the problems are so immense that it’s easy to make a lot of progress with even a tiny bit of effort?)

1) Quality Control – so much of the mass communication of evolution is so dull and uninspiring. Two specific examples – the 8 part Evolution series by PBS released a few years ago and the half hour video produced last year titled, “Evolution, Why Bother?” sponsored by AIBS. We ordered the 7th episode of the Evolution series, on God and religion, and found it unwatchable. At one of my recent screenings a member of the audience offered up that she ordered the second episode for a museum display and found the same thing – five minutes into it they shut it off. The AIBS video is tragically bad – nothing but talking heads and still images. It doesn’t matter how little budget they had, any introductory film student could have explained to them that film/video is a visual medium. The primary communication takes place through the images presented. When all you show are people’s faces talking, you are saying virtually nothing. These sorts of productions need the simple, honest feedback of evolutionists who have purchased their videos, shown them to their neighbors, and watched them fall asleep. Just send them a note and say this is not good enough. Raise the bar. Its that simple. When evolution media looks bad, evolutionists look bad. Cost of this Suggestion (to give media producers, including me, your critical feedback) to you: $0

2) Attitude – “Never rise above.” It’s one of the simple principles we learned in acting class. Whenever you condescend (as perhaps I did in the above paragraph) you lose the sympathy of your audience. Plain and simple. When evolutionists call intelligent designers idiots, its fine among evolutionists, but for the broader, less informed audience, it just makes everyone side with the people being condescended towards. It’s a simple principle of mass communication. Furthermore, even though Stephen Jay Gould was my hero in graduate school nearly 30 years ago, today he is culturally irrelevant for undergraduates at the introductory level. His essays, which I cherished as an introductory student back then, are now unusable. My students at USC literally asked me to never assign them his essays again. They find his style and voice to be arrogant, elitist, condescending, verbose … the list goes on and on. Cost of this Suggestion (to avoid rising above) to you: $0

3) Concision – it’s a byproduct of the information era. Get used to it. In fact, practice it. The most effective means of communication is through storytelling. The shorter, more concise, and punchier the story you can tell, the greater the interest you will hold with an audience. And yes, as a scientist you need to maintain accuracy and sometimes even precision. But still, just practicing being shorter and punchier doesn’t hurt anything. And you can see the results of this in Hollywood and advertising pitchmen – through sheer practice they are able to tell entire stories in very few words. Cost of this Suggestion (to practice being concise) to you: $0

4) Modernization – A CNN poll two years ago showed that 44% of Americans get their information on science and technology through television – more than any other medium. We are a television society. So why isn’t the world of science communication geared towards this, even just a little bit? This is a question you can ask of the major science agencies. There are now dozens of science writing programs around the country, but no Science Electronic Media programs. Cost of this Suggestion (to realize how mass media has changed from print to electronic) to you: $0

5) Prioritization – Effective communication costs money. Real, cold, hard dollars. Scientists tend to look at communication as a funny, frivolous option that is meant mostly for those who are predisposed to it. As a result they sit through technical talks with bad visuals and poor sound, and really don’t care. You can see this every week in your local departmental seminar. But on a higher scale, you see it in the tiny prioritization of science communication in research grants. Occasionally a few dollars are allocated for “outreach.” But compare this sort of prioritization with businesses making commercial products where they accept the need to spend perhaps half of their budget on marketing and advertising. This isn’t to say that scientists should turn themselves into cheap salesmen (which is the resentful complaint I hear to this suggestion), but the fact is the 9/11 Commission was the first government study to accept the need to allocate equal resources to its communication in order for it to make a difference. EVERYONE needs to accept we now live in an information-glutted world, and if you don’t pay sufficient attention to the communication of what you have to say, then what you have to say will go unheard. It’s a matter of priorities. Cost of this Suggestion (to allocate more funds to communication) to you: as much as you can afford – its time to make it hurt a little, to make up for the lack of prioritization in the past

6) Understanding – intellectuals are handicapped as mass communicators. I had this line in my film, but took it out because it sounded too insulting. But its true. Mass audiences do not follow people who think, they follow people who act. Intellectuals are trained to think, not act. Its one of their charming traits, but it’s also a handicap. Try taking an acting class and you’ll get to know about this intimately. And it’s not that you necessarily need to do something about this right now, it’s just that you need to start developing some awareness of it. Cost of this Suggestion (to consider the consequences of being too intellectual) to you: $0

7) Risk Taking/Innovation – every stock investor knows you allocate at least 10% of your stock portfolio to high risk ventures. The voices of mass communication of science today are very homogenized. There are no signs that formal investment in high risk innovation of science communication has been taking place. You need to look at your science agencies and ask what percentage of their funding is going to high risk, wild ideas. They may sound irresponsible, but without them, you end up with homogenization. Come on, folks, we’re talking about basic out-breeding dynamics here. Cost of this Suggestion (to take a few chances) to you: $0
Humor – it’s yet another byproduct of the information era. It’s no coincidence that news anchors, who were stoically serious 30 years ago, today tell jokes and tease each other. Or that The Daily Show on Comedy Central is the most popular form of news for kids (as well as A LOT of adults). Or that Michael Moore, Al Franken, and Bill Maher have become such popular news critics. It’s a major channel of communication. So lighten up, evolutionists. Cost of this Suggestion (to lighten up a bit) to you: $0

9) Unscripted Media and the Mass Audience – this goes with modernization. Whether you realize it or not, the mass audience has changed drastically in just the past decade. About half of the acting jobs that were available a decade ago in Hollywood have now been lost to reality television, which is a form of “unscripted entertainment” (yes, I know that even reality shows have a great deal of structure to them, but they are still far more unscripted at the fine scale than the standard sitcoms and dramas). The mass audience is bored, and desperate for anything unpredictable. Which is why when Richard Prum, in a moment of brilliance, yanked the microphone away from me as I was droning on about the need for spontaneity, the audience erupted more than any other moment in the entire evening. Cost of this Suggestion (to be more spontaneous) to you: $0

10) Sincerity – and furthermore, even though Dr. Prum was a bit ungainly in his performance after grabbing the microphone, the audience didn’t care. The gesture was so sincere, came from such a visceral level, showed such passion, such risk-taking, so much desire to act (rather than just pontificate as I was doing), that he stole their hearts. There is a great deal to be learned from that. Cost of this Suggestion (to be more sincere) to you: $)

Last night I drove into New Haven, Connecticut, to catch an advanced screening of Flock of Dodos, a movie about evolution and intelligent design. Afterwards I took part in a panel discussion. It was an interesting evening, not only because the movie was quite good, but because it provoked a noisy discussion.

I don’t want to give away too much of Flock of Dodos, because I would prefer that a lot of people get a chance to see it for themselves. Randy Olson, the creator of the film, spoke after the film and explained that the version we saw was still a bit rough around the edges, and he’s getting ready to enter it into various film festivals and hopes to get distribution after that. I wish him well.

To be brief, then, Olson is a biologist-turned-filmmaker who got a bit baffled by the rise of intelligent design and decided to investigate, heading back to his native state of Kansas. He talked to school board members, intelligent design advocates, and evolutionary biologists. Olson’s a friendly, open guy who can share a beer with a creationist without getting it splashed in his face. But in all the laid-back conversation, he offers some pretty penetrating observations of the intelligent design movement. A creationist board of education member winks and smiles with a mix of flirtation and cynicism. An intelligent design advocate declares that all biology textbooks promote the lies of Haeckel about embryos and evolution, only to start paging through the textbooks in his office in a futile search to find any mention of Haeckel. A cardiologist who is one of the leading champions of intelligent design in Kansas doesn’t even know which scientific meetings he would go to present his research, if he had any research to present.

Olson weaves in interviews with evolutionary biologists, who clearly make Olson want to bang his head against the wall. They’ve got the science right, but they can be inarticulate and high-handed, torpedoeing their own cause. Their efforts at communication to the public are stiff and a bit arrogant. Meanwhile, intelligent design advocates have hired the PR firm that brought us Swift Boat Veterans for Truth.

The movie does a nice job of conveying the past few years of school-board shenanigans, including the Dover case. And it’s funny. It hits the same personal, low-key humor struck so nicely by Morgan Spurlock in Supersize Me. Spurlock made his point about American eating habits more effectively than a semester’s worth of lectures from nutritionists. Olson makes his point about the emptiness of Intelligent Design more effectively than a lot of scientists themselves have.

The premiere packed an auditorium at Yale with a couple hundred people creating all sorts of fire hazards. After the movie, the other panelists and I sat down to talk. John Hare, a theologian at the Yale Divinity School, said he enjoyed seeing the intelligent design sympathizers portrayed not as yahoos but as people, as well as seeing evolutionary biologists portrayed as bastards. (His word, not mine–the first time I think I’ve heard a theologian use the word bastard, now that I think of it.) Hare was half-joking; he explained that a lot of the trouble over evolution–needless trouble, in his view–came from those who would try to explain every tiny facet of human existence as the product of an adaptation finely honed by natural selection.

I talked about how my own experience as a science writer certainly meshed with some of Olson’s own experiences. I can remember getting into discussions with biologists five or six years ago about the rise of intelligent design, and they would just give me blank stares. When I explained what was happening beyond their lab, most of them seemed to assume that I could only be talking about ten or eleven people very far away. Once intelligent design began popping up in newspapers and magazines and education standards, the biologists did perk up and take notice. But their responses were not quite up to the challenge. I recounted how a bunch of representatives from a lot of scientific societies gathered for a meeting on challenges to evolution and came away a clarion call to action: each society would post a statement in support of evolution on their society’s web site. Other biologists didn’t even think it was their place to get involved. If not them, I wondered, who?

The other panelist was Richard Prum, an ornithologist who has done lots of important work on the evolution of birds. (I’ve reported on some of his work in the New York Times and elsewhere.) He put up with our semi-constructive criticism pretty well. He was asked to come up with a short and sweet slogan to go up against the creationist “Teach the Controversy.” Harkening back to ID advocate Michael Behe’s testimony at the Dover trial that astrology would qualify as science under his definition, Prum suggested, “Teach Astrology.”

But for all the goodwill, you could tell that Prum felt that some of Olson’s complaints were a bit unfair. In Flock of Dodos, the biologists all come off as stiff, tongue-tied, and unemotional. That portrayal serves Olson’s message, which is that biologists have to become much more media-savvy or risk the fate of the dodos that give the movie its title. But Prum pointed out that evolutionary biologists aren’t just sitting around at the Discovery Institute getting paid to write op-ed pieces. They’ve got full-time jobs doing science and teaching students. It’s more important for them to do good research than to put out a snappy press release.

The issue continued to itch away under Prum’s skin when the discussion was opened up for questions from the audience. One person asked what Olson actually thought scientists needed to do in the current climate, and Olson began to talk about how scientists needed to learn to be more spontaneous. And in the middle of Olson’s reply, Prum grabbed the microphone and said, “You want spontaneous?” He stood up, his chair flying back, and held the mike a bit too close to his mouth so that his voice was weirdly fuzzy. I’m obsessed with birds, he said. Believe me, it’s not hard to get excited about evolution. But we just don’t have that much effect on what people are thinking in this country.

It was a disconcerting sight, because Prum has the very cheerful, easy-going demeanor of a man who loves birds and the fact that he gets to study them for a living. (Exhibit A) At first Prum may have thought his outburst would be a funny joke, and a dramatic way to respond to Olson’s jabs. But the passion really did sweep through him, to the point that his hands were shaking. And the audience broke into wild applause.

Olson just smiled and said, “Now, that’s spontaneous.”

I think Olson’s portrait of scientists was a bit of a caricature. Ken Miller of Brown has proven that biologists can talk about evolution in an engaging way, and his testimony played a key role in the devastating crushing of intelligent design in Dover, Pennsylvania. And while some scientists still think that issuing a statement on a web site no one visits is bold action, other scientists have explored new ways of communicating evolution, from games to blogs. But there can be a lot of truth in caricature, especially when it’s stammering and stumbling to explain evolution in plain terms.

The evening ended with a student in the back making the case that, like it or not, evolutionary biologists do work that has profound implications for people’s lives. “If I have to quote Spiderman,” he said, “it’s a great power you have. And with great power comes responsibility.”

And with Spiderman on our minds, we decamped for beer.

Or at least at the bottom of a movie poster.

The movie Flock of Dodos, which takes a look at the evolution-creationism struggle, will have a free showing on Monday in New Haven, Connecticut. I’ll be there as part of a panel discussion after the movie, moderated by Michael J. Donoghue, the director of Yale’s Peabody Museum. The panel will also include Randy Olson, the director of “Flock of Dodos”‘ John Hare, a theologian at the Yale Divinity School; and Richard Prum, a Yale evolutionary biologist who specializes on the evolution of birds. Not having seen the movie, I can’t offer a review, but I certainly am curious to see it.

Details here, map of the venue (Luce Hall) here.

Dinosaur paleontologists don’t look for fossils simply because dinosaurs are cool. They want to solve evolutionary mysteries. Like all living things, dinosaurs form groups of species. You’ve got your long-necked sauropods, your head-shield-sporting ceratopsians, and so on. The distinctiveness of a group can make it difficult to determine how it evolved from an ancestor. Whales may be mammals (they nurse their young, for example), but they’re all fish-shaped.

Some of the best clues to the origins of these groups come from transitional fossils, which are formed by species that evolved some, but not all, the traits that set a group of species off as a group. Transitional fossils can sometimes be very weird. My personal favorites are the early tetrapods (basically fish with fingers) and the early whales (whales with feet). But that’s probably because they were the subject of my first book. Each year brings new transitional fossils to choose from. And now comes the latest addition: Guanlong wucaii, a forerunner of Tyrannosaurus rex.

T rex and its kin–known as tyrannosaurids–were a particularly distinctive bunch. They had big heads with fearsome teeth, little arms ending in two-fingered hands, long legs, and a massive overall body. That distinctiveness made it hard for paleontologists to determine exactly where in the dinosaur family tree they fit. Thus Guanlong comes as such a delight. In a paper published today in Nature, a team of paleontologists from China and the United States describe two skeletons of Guanlong, discovered in western China. It lived about 120 160 million years ago, and measured up to nine feet long. It sported a number of traits that are found only in tyrannosaurids. Some are pretty easy to recognize, like the fusion of the nasal bones in the skull into a single unit. Others are a bit more esoteric, like the “centropostzygapophyseal lamina on cervicodorsal vertebrae.” (And breathe….)

But Guanlong lacked some of the traits found in better known tyrannosaurids. For example, it had three fingers instead of two. Only after Guanlong branched off that other tyrannosaurids lost one of their fingers. This and several other key differences set off Guanlong as a very primitive tyrannosaurid.

The scientists combined the information about Guanlong with information about other dinosaurs to calculate their most likely evolutionary relationships. Tom Holtz of the University of Maryland, who has contributed some excellent comments here at the Loom, wrote an accompanying commentary on Guanlong. It includes a nice illustration of that tree, showing the ages of the different lineages based on their fossils. Guanlong appears at the base of the tyrannosaurid branch. The similarities Guanlong has to certain other dinosaurs helps reveal the closest relatives of tyrannosaurids. On a superficial level, tyrannosaurids look a lot like an older group of dinosaurs called carnosaurs. But that resemblance is just a result of convergent evolution. In fact, the scientists conclude, tyrannosaurids evolved from a small two-legged ancestor that also gave rise to several lineages including one alive today: birds. Here’s the tree:

Guanlong’s place on this tree led the scientists to reconstruct it with the primitive feathers shown here. The branches closest to Guanlong on the dinosaur tree have yielded fossils with feather-like impressions (that includes Dilong, itself a tyrannosaurid). So it’s reasonable to infer that Guanlong had them too–not full-blown flight feathers, but simpler ones that appear to have been the evolutionary precursors of bird plumage.

I certainly wouldn’t want to bump into Guanlong in a dark alley, but as tyrannosaurids go, it wasn’t very big. As Holtz points out, it would have been dwarfed by big carnosaurs. It would take over fifty million years for tyrannosaurids to get to the monstrous sizes of T rex and its closest relatives.

As this evolutionary tree makes clear, Guanlong was an ancient relative of T rex, not a direct ancestor. After its lineage branched off from the other tyrannosaurids, some unique traits emerged. One of them is quite obvious in this picture: its enormous crest. This thin wedge of bone wouldn’t have helped the dinosaur in a fight, which leads the paleontologists to propose that it was a sexual display. Crests appeared on some other dinosaurs, not to mention their close flying relatives, the pterosaurs. Here’s a picture of Tapejara, a wonderfully bizarre species discovered in Brazil.

And just a few thousand years ago, another extravagant piece of headgear could be found on the Irish elk, shown here.

There’s a remarkable disconnect between these sexual displays and the rest of the bodies to which they’re attached. Guanlong looks very much like its closest relatives except for its crest. Tapejara has a standard pterosaur body. Take away the Irish elk’s antlers, and the rest of the skeleton remains very much like those of living elk and deer. Sexual displays show signs of evolving very quickly, thanks to the big difference they can make to a male’s reproductive success. But other parts of the body take much longer to evolve and tend to stick around once they’ve appeared.

Don’t insult leeches.

I’ve got an article in tomrrow’s New York Times about the discovery of a remarkable case of convergence: an ancient relative of today’s crocodiles and alligators that evolved a dinosaur’s body–80 million before the dinosaurs evolved it. Here’s the paper.

Update, 1/26 7 am: Here’s Seth Sean Murtha’s nice sketch of Effigia okeeffeae. A bigger version is here.

Update, 2/1 9 am: Be sure to check out Carl Buell’s croc gallery.

My review of the Darwin show at the American Museum of Natural History is in the new issue of Discover. You can read the full text here.

Last year was the hottest on record, or the second hottest, depending on the records climatologists look at. The planet has warmed .8 degrees C over the past 150 years, and scientists are generally agreed that greenhouse gases have played a major part in that warming. They also agree that the warming will continue in the decades to come. Many experts are concerned that warming may make two unpleasant things more common: extinctions and diseases. In tomorrow’s issue of Nature (link to come here), a team of scientists report on a case that ties these two dangers together: frogs have become extinct as climate change spreads a deadly fungus. It’s an important study, but it can’t be boiled down to simple slogans. It highlights the dangers of global warming, but it shows that global warming’s effects can be counterintuitive and unpredictable.

Since the 1980s, scientists have observed that frogs and toads have been disappearing. Species that live in mountain cloud forests in the tropics have been particularly hard hit. Take Harlequin frogs (Atelopus). Scientists have described 110 species from Central and South America. But they can no longer find a single individual from 67% of those species. They’ve been identifying potential agents of the extinctions. It’s been much harder to pinpoint the actual culprit (or culprits).

Climate change was one suspect. Species that live in mountains may be particularly vulnerable to warming temperatures because they live in small ranges. If it’s too hot for an animal at 5,000 feet, it may respond by moving uphill. But it can’t go uphill forever, and before long its range may simply vanish. Another leading suspect was a fatal fungus, which has been sweeping through frog populations in recent years.

There was some reason to think that the two suspects might be working together. Scientists have found some evidence that warmer temperatures encourages the spread of diseases. Pathogens that might be killed off by cold weather can thrive if the climate changes. It was also possible that warmer temperatures were putting stress on the frogs, making them more vulnerable to attack.

This might all sound quite logical, but some evidence didn’t seem to fit in. In one Australian study, for example, the fungus proved deadlier at cooler temperatures. When scientists exposed 16 frogs to the fungus at 17 degrees C all died. But only 4 out of 8 frogs died at 27 degrees C.

A network of 75 scientists came together to sort this mystery out. They gathered data on almost all the harlequin frog species, including weather records for their ranges. If a major force has been driving a lot of species to extinction, it should be easier to pinpoint than the cause of a single species’s disappearance.

The results indicate that global warming has had a hand in the extinctions. The warmer the average temperature is in the tropics in a given year, the more likely that frogs are going to disappear in the following year.

But the results also clash with simple notions of how global warming can drive extinctions. The most vulnerable harlequin frog species live between 1,000 and 2400 meters. Harlequin frogs living at higher elevations have actually suffered fewer extinctions. So vanishing real estate is not to blame (at least in this case).

The study is also a vivid illustration of the fact that global warming can lead to lots of strange local climate change. At several research stations in the study, scientists have found that the maximum daytime temperature has actually gone down. At night, on the other hand, the minimum temperature has been going up. Clouds may be causing this pattern. Global warming causes more water to evaporate, creating more clouds in mountain forests. At night these clouds may trap heat, keeping the forests warm. But in the daytime, incoming sunlight may bounce off the clouds, leading to cooler days.

It’s these local peculiarities of climate change, the scientists argue, that may be helping the fungus kill harlequin frogs. The fungus doesn’t like temperatures over 28 degrees C and dies at 30 degrees C. It can’t survive in lowland forests, and even a harlequin frog living on a mountain could cure itself with a good bake in the sun. But these days that frog is less likely to find a spot of sun, thanks to the increasing cloud cover. On the other hand, very cold temperatures keep the fungus from growing. The highest elevations are still cold enough to block its spread, the scientists argue, which is why harlequin frogs have suffered fewer extinctions there. But as nights get warmer, the mid-elevation forests are becoming the perfect breeding ground for the fungus. And harlequin frogs there have paid the price.

I’m writing this post just before this paper goes public, and I’m cringing at the thought of how it will be spun. I’ve seen how pseudo-skeptics try to claim that we can’t learn anything about extinctions or how they might be accelerated by future climate change (see my posts here, here, and here). On the other hand, it would be wrong to make a blanket statement that climate change triggers outbreaks because it makes the planet warmer. The equation is far from simple. If not for some cooling, fungi would not be such a threat to harlequin frogs. This interplay is not just complex but hard to forecast. Scientists have known about global warming and fungus outbreaks and frog extinctions for twenty years. But as far as I know, no one predicted that it would be nighttime warming and daytime cooling that would make the fungus so deadly. A commentary that accompanies the new paper in Nature points out that few computer models used to forecast climate-driven extinctions take parasites into account. And so we have no idea just what sort of future the Harlequin frogs are pointing us towards.

Governor Ernie Fletcher of Kentucky uses his State of the Commonwealth speech last night to plug intelligent design:

As I close, let me recognize Kentucky’s veterans. You have served to protect our liberty and the freedom that spurs our quality of life in this nation. Please know that this administration is committed to supporting you.

This is not a question about faith or religion. It’s about self-evident truth.

Did you know that the Declaration of Independence was a biology textbook?

I’m going to create a new tag for these little entries. I hope I won’t be adding too many more entries to it, but I won’t be surprised if I do. [Update: See under "Our Dear Leaders Speak"]

(Hat tip: Ars Technica)