davegodfrey: Coelacanth (Science)
The entire world seems to have gone utterly insane over this fossil, known colloquially as "Ida", but officially as Darwinius masillae. And it is a lovely fossil. It is also important because it will, I'm sure, tell us lots about what was going on in primate evolution 47 million years ago. I'm not going to go through the reports because there are too bloody many of them, but I will point out that while many have fallen for the "Missing Link" Found! angle plenty of others- especially the bloggers writing opinion pieces are being rather more restrained.

However utterly revolutionary it is not. At best it means a group of animals a bit like lemurs (Adapids) are more closely related to apes and monkeys than a group of animals a bit like Tarsiers (Omomyids). Be honest had you heard of either?

I quite like it because its another species published in PLoSOne (The Public Library of Science). This is an open access journal, so anyone can download and read a copy of the paper for free. There's a lovely long description of the fossil- it is young (under a year old), female (it lacks a baculum [penis bone] which you'd expect to see in male primates like this), and very nicely preserved (the body outline, hair and stomach contents are all preserved).

Its from the Messel deposits, which have yielded beautiful fossils of fishes, early horses, ants, weird mammals like Leptictidium, and all sorts of other things. Messel was covered in one episode of David Attenborough's 1980s series on fossils Lost Worlds, Vanished Lives, and also in the first episode of Walking With Beasts- though proto-whales aren't known from the area. I can't believe someone thought it was a good idea to turn the site into a rubbish dump. Fortunately they haven't, and it is now a World Heritage Site.

I am not qualified to say how much this fossil supports the conclusions that the authors are trying to draw- that the group to which Ida belongs are more closely related to monkeys and apes than tarsiers and their relatives are.  However the paper lacks a phylogenetic analysis and as Laelaps and The Open Source Paleontologist points out this is something one expects to see when claims for moving large groups around are made. Hopefully one will be done soon, and the question of whether Adapids (the group to which Darwinius belongs) is closer to lemurs or monkeys and apes will be better resolved.

I don't really have much to add to the criticism of the hype either. Both Ed Yong and Carl Zimmer have covered it far better than I could hope to. Especially Ed's post.

Personally the part that really annoys me- I wouldn't be at all surprised if the view of the Adapids in the paper turned out to be wrong. You just know that the creationists will have a field day because while I'm sure most of you know that the great strength of science is that whenever new information appears which contradicts its conclusions we change our minds- something the creationists seem incapable of appreciating as being A Good Thing. I just hope I am pleasantly surprised.
davegodfrey: South Park Me. (Default)
Mark Witton (who as well as being a pterosaur bod is a fabulous artist- seriously check out the flickr set) has identified a new genus and species of pterosaur. This time its published in Palaeontology, so unlike last time not everyone can go and read the paper for free. Fortunately Mark blogs as well as publishes his art on the flickr site. (The article in question is here, together with the images used to publicise the paper in the press). Go read it, its a very interesting article on some of the problems encountered when working with specimens.

As with his joint paper with Darren Naish on Azdarchids its made the national press in several papers. Luscovagus magnificens ("Magnificent Lake Wanderer") comes from the Crato Formation in Brazil, belongs to a group of pterosaurs called the azdarchids (along with the more famous Quetzalcoatlus), specifically a group called chaoyangopterids. A recognisable (but not unique) character is that azdarchids don't have teeth.
The University of Portsmouth's press release about this find says "The finding is significant because it originated in Brazil and is the only example of the Chaoyangopteridae, a group of toothless pterosaurs, to be found outside China and is the largest one ever discovered." This sentence may become important later.

The Independant has an nice article, describing how the specimen had been lurking in a museum drawer in Germany (as so many are), that it was preserved in manner that was awkward to interpret, and that we don't have much of it, so we need more specimens, but that because its a long way from China it demonstrates nicely how much we don't know about these animals. A third of the article is quoted directly from Mark, and its a rather nice article. No glaring errors, nice big images through a link, well done Indy.

The Daily Mail thinks there's a team involved. (Well, there would be several people doing the CT scanning, but only Witton's name is on the paper). Other than that pretty much everything's the same as the Indy article, quotes from Witton, etc. The website shows both illustrations- I do like the scale silhouette of Witton scratching its chin.

This time aroud its the Guardian that fails miserably. "Giant Flying Reptile- Terror of Cretaceous Skies" proclaims the headline. "Lacusovagus magnificens, the magnificent lake wanderer, is the largest prehistoric flying reptile without teeth ever to have been found." The article goes on to say that though its big its dwarfed by some of the toothed pterosaurs, quoting Quetzalcoatlus and Hatzegopteryx as being much bigger. Unfortunately those species are both toothless. as are all the azdarchids I'm aware of. Pteranodon was also toothless, (as the name suggests), and had a wingspan of about 7-8m and has been known since the 1880s. If you have links to the paper describing Hatzegopteryx you'd think you might do a bit more basic fact checking. But no.

Can it get worse? You bet.

The beeb?, Virtually identical to the Indy. Both the Telegraph and The News in Portsmouth call it a dinosaur, which is a glaring error, but otherwise get everything right.

And now the Metro. I think you know what to expect. The article is only five sentences long, including the headline. The headline calls it a dinosaur. It then states that it is the first toothless pterosaur found outside China. Now unless they got the name of the animal, where it was found, or how big a "family car" is they couldn't have fitted more errors in the article.

I therefore have one request to make of Metro. If you can't even read a press release, please stop reporting science. You wouldn't tolerate this if you were reporting on football. You wouldn't be allowed to.
davegodfrey: Coelacanth (Science)
Some of you may have seen this paper at PLoS ONE. Its a rather nifty piece of work by Darren Naish and Mark Witton (who's very nice drawings accompany the article itself, and the various newspaper reports.)

Basically a group of pterosaurs called Azdarchids have always been a bit of a problem for palaeontologists working out their lifestyle. They're huge, with 10m wingspans, 2-3m jaws, and "it could look a giraffe in the eye". Originally suggested to be variously scavengers, "dip feeders" (like albatrosses), and mud probers, but they don't have the right sort of beak for any of those. Along with every other bloody pterosaur they've been suggested as a "skim feeder"- but no pterosaur is nearly as specialised as Rhychops the skimmer.

Naish and Witton therefore reconstruct them as stork-like predators. The fossils are mostly found in terrestrial deposits, and their footprints indicate their feet aren't adapted for wading (another popular hypothesis)

Yet again coverage is varied. The best place is of course the paper itself, freely avaliable online. Or you can read Darren's blog about it. I wouldn't bother too much about the rest of the media though. 

  
ETA: The Economist, another short article, and nothing wrong here either. States the research showed that they "were more like giant storks. Rather than skimming the sea, they plucked their prey from the ground." Better than the Sun article, but frankly not that much. Again, shorter seems to be better.
davegodfrey: Coelacanth (Science)

Oh dear. What starts off as a musing on a small part of Wagner, rapidly turns into a discussion of evolution. Jerry Fordor (who?) wants to know why pigs don't have wings. He doesn't like natural selection. Which is a pity because while adaptationism is sometimes taken too far it still works and is still the most important driving force in nature.

Fodor doesn't like evolutionary psychology much. Fair enough, I'm not too keen on its excesses (like the recent non-study suggesting that girls prefer pink and boys blue). However it is not unreasonable to suppose that our behavioural patterns evolved in response to living on the savannah. As the majority of humans don't live in hunter-gather groups it isn't much of a stretch to suggest that some of the problems we have with modern life are because the behavioural modules that worked then don't work now.

Fodor distinguishes the two parts of "Darwinism", phylogeny and natural selection. (You can always tell if the essayist is going to get it badly wrong when they use the term "Darwinism" to describe modern evolutionary theory. I'd like to see a ban on the word outside of its historical context.) He then introduces the idea that adaptationism cannot explain everything, bringing up Sephen Jay Gould's analogy of the spandrels of San Marco. A spandrel is a triangular space which you get in the corners of arches when they are supporting a dome. They are often highly decorative.  If you support a dome with arches you automatically get spandrels. Similarly in biology there is debate about how significant natural selection is in producing a particular phenotype. Some people, like Larry Moran and the late Stephen Jay Gould see a greater role for mechanisms other than natural selection. Others such as Richard Dawkins and Simon Conway Morris don't think these ideas are useful. Nobody contends that natural selection is the be-all and end-all.

Except it seems Mr Fodor. Fodor also doesn't like the fact that artificial selection is a good analogy for natural selection because nature isn't conscious. 

               "How could a studied decision to breed for one trait or another be ‘the very same thing’ as the adventitious culling of a population?" 

Fodor asks. Well, because NS doesn't necessarily proceed by culling. All you need is for the organisms with that trait to have a couple more children in order for the trait to spread. As far as evolution is concerned having no kids is the same as being dead. Fodor has got rather too wrapped up in the "survival of the fittest" analogy to see that it isn't always like this.

              "The crucial test is whether one’s pet theory can distinguish between selection for trait A and selection for trait B when A and B are coextensive: were polar bears selected for being white or for matching their environment? Search me; and search any kind of adaptationism I’ve heard of. Nor am I holding my breath till one comes along."

Um, polar bears live in a predominately white environment. If they didn't maybe they wouldn't be white? Why bears might be white in a non-white environment is an interesting question however. (But not relevant to Fodor's thesis).

Fodor seems to think that evolutionary development is a far more important part of evolution than natural selection is, discussing why pigs don't have wings, and correctly surmising that they are constrained by their embryology. There's nowhere to grow them without radically redesigning the tetrapod body-plan. Organisms have all sorts of constraints placed upon them by their biology, and it makes it very interesting to see how they solve particular problems, or failed to develop particular solutions. Bats pterosaurs and birds sacrificed a pair of limbs to fly. Insects used a different solution and still retain all their original legs.

However this harks back to the old orthogenetic arguments of biologists like Cope, and others Wiliam Patten wrote that "Natural Selection cannot create it can only sift". Natural selection plus mutation can do all sorts of things.

The traits we see are the result of pre-existing constraints, fiddly bits that come along for the ride and are kept because they aren't harmful, all mediated through natural selection. If an evolutionary spandrel was harmful it wouldn't hang around very long. One of the most important parts of evolution is "stabilising selection"- keeping things the same because they work, and penalising deviations from the norm because they don't. This works in artificial selection too.

So, in all a mixed bag. It had the potential to be a good essay, but as so often happens the "Darwinism in crisis!!" angle has been massively overplayed, and Fodor seems to have thrown the baby out with the bathwater in his realisation that things are a littl emore ocmplex than they appear at first.

davegodfrey: Coelacanth (Science)

Yet another aberrant theropod from China. Called Gansus yumenensis, after the area it was found its 100 million years young. It looks a lot like the modern diver (or Hesperornis a large flightless toothed bird.) Feathers and the webbing between the toes is preserved. Sadly its missing a skull. But its still pretty. And ist shows the kind of diversity of bird species and ecotypes during the Early Cretaceous. The sad thing is that you won't see some of the variety of birds that probably existed because they lived on land, and never got fossilised. Our history of bird evolution is largely known from seabirds.

Its from another deposit in China with soft-tissue preservation, but not one I'd heard of before.  Still in a country that big I'm not suprised there are so many.

Metro thinks this is important. So important that it shows that birds evolved from fish! ARRRGH!!! I'm going to have to give up reading it. Its bad for my blood pressure.

davegodfrey: Coelacanth (Science)

Three updates in a day!

I used to admire and respect Robert Bakker, the enfant terrible of vertebrate palaeontology- many of his ideas in "The Dinosaur Heresies" were wrong, but at least they were interestingly wrong, in a way that made people say "that can't be right, lets go out and show the beardie hippie that he's wrong". Now I'm beginning to think he's going a bit daft. Ok so naming a plesiosaurus Attenboroughsaurus is perfectly sensible. But hogwarts?

And then Metro, ever the bastion of accurate scientific reporting states that this animal is important because:

A: Its named after bloody HP's bloody school, what next? Opusdeius danbrowni? The name you give an animal doesn't matter unless another animal already has it. I know it shouldn't annoy me, and to be honest it doesn't - not compared to reason B. However naming things after popular culture items is always a little dodgy. So many things don't last. I could name a species after Crom, Conan's god. But I don't think anyone else (other than [profile] steely_glint, and some of the other people I know would know what the bloody hell I was on about.)

B: Its the only dinosaur with a flat head known from the Cretaceous. Nooo! Its the only Pachycephalosaur with a flat head known from the Upper Cretaceous of North America- there's a couple of "flat-headed pachycephalosaurs" from Europe - Yaverlandia from the Isle of Wight fr'instance. Not to mention all the dinosaurs that aren't Pachycephalosaurs that have flat heads.

Damn you Metro and your utterly hopeless science reporting.

davegodfrey: Coelacanth (Science)
Metro: Friday February 24th 2006

“Found: The world’s oldest beaver”

This artist’s impression may appear to show a common or garden beaver. But don’t be fooled. This is, in fact, the Castrocaudata lutrasimilis, a previously unknown mammal species whose discovery by German scientists may force a rethink of th theory of evolution. A fossil of the 45cm (18in) “Jurassic beaver” was unearthed in China. It is 164million years old, making it the oldest sizeable mammal remains ever found. It is significant because scientists believed mammals did not develop until after the extinction of the dinosaurs 65million years ago. Now they may have to revise their theories, the journal Science reported.

NO!!! What we would probably recognise as modern mammals are about 200 million years old (depending on exactly how you define a mammal- it all gets a bit complicated with “stem groups” and such). No-one since Richard Owen, IN THE NINETEENTH CENTURY has suggested that mammals originated after the K/T boundary.

This fossil is interesting because it is the first big mammal, (everything else up till now has been very small), and it shows adaptations to a semi-aquatic habit (Castorcaudata means “Beaver tailed” and lutrasimilis translates as “like an otter”). It also comes from a new locality- and where there’s one, there are probably more…

What haven’t been found (and where the writer may be getting confused) is that no members of recognisably modern groups are known from before 65 million years ago. For instance Eomaia is an early placental mammal from the Cretaceous, but it isn’t definitely closer to any one group of modern placentals than another.

As I write this I’m listening to the “In Our Time” on the Rise of Mammals, which despite its faults goes into detail about the evolution of placentas, etc. THE FIRST SENTENCE IS “MAMMALS ARE SURPRISINGLY OLD.”

Still, the artist’s picture is quite pretty- think a beaver with a shrew’s head- and winglike extensions to the limbs. (So not actually that much like a beaver then…)

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