Thursday, December 24, 2009

Why Dinosaurs Hate Christmas

Back by popular demand.

Did you know that most dinosaurs hate Christmas? It’s true, they do. And it’s not because they couldn’t get a handle on the present wrapping (or unwrapping for that matter) either. No, there is a very good reason why Dinosaurs hate Christmas.

However, before explaining why dinosaurs hate Christmas, lets deal with some startling new information. Everyone is familiar with the standard explanation for the extinction of the dinosaurs. I've included a common representation of the event.

However, startling 'evidence' has been presented which suggests another reason for what happened. The evidence is still officially hidden by the authorities, but one startling image has been smuggled out and is shown here for the first time.

It is claimed that it was an early experiment on propulsion systems that went wrong and had to be ejected. Shocking as this image is, there are some who claim that it is a forgery and just another shot by those at war with Christmas.

However, this is not the reason that dinosaurs hate Christmas. To understand that we need to know what dinosaurs are.

In his classic 1842 publication on dinosaurs, Richard Owen named and defined the Dinosauria as:
a group of exceedingly large, pachydermous reptiles from the Second Age . . . includes Megalosaurus, Iguanodon and Hylaeosaurus.

In 1997, Tom Holtz provided a different definition:
the last common ancester of Megalosaurus andIguanodon and all its descendants.
If it's changed since then, blame Holtz, but any changes will be mainly deckchair shuffling on the SS Chicxulub.

Anyhow, the thing about this definition is that, nestled between the Megalosaurs and the Iguanadons, are the Dromaeosaurs, and directly related to the Dromaeosaurs, and so one of the descendants mentioned above, is a little group called Aves!

So with the mass slaughter of birds dinosaurs every Christmas, wouldn't you hate Christmas?

If you insist in participating in this slaughter, at least make sure you cook your dinosaur correctly:

1. If your dinosaur is frozen, fully thaw it.

2. Don’t stuff the dinosaur. By the time the stuffing reaches a safe temperature, the meat is overcooked.

3. Cover the dinosaur breasts with ice while the rest of the dinosaur warms to room temperature. Don’t leave the dinosaur out for more than 3 hours. At this point, the breast will be about 4 centigrade (40o Fahrenheit), while the rest of the meat will be at 16 centigrade (60o Fahrenheit).

4. Put the dinosaur in the oven and cook according to your favorite recipe.

5. With a meat thermometer, check temperature. Take out of the oven when legs reach 82 centigrade (180o Fahrenheit) and breast hits between 68 and 71 centigrade (155o and 160o Fahrenheit).

Ho Ho Bleedin' Ho.

Let It Snow, Let it Snow, Let it Snow.

Snow at Christmas. Yay.

Well, snow just before Christmas anyway. And no, it's not snowing in Australia, I'm in London for Christmas and January.

Missed the Eurostar debacle by a few days, so snow and an uneventful trip from Paris to London by train. Things are looking good.

Chocs and wine at the ready, Saturnalia is go. Lo lo lo.

Thursday, November 19, 2009

Livelife 3 - Tiliqua rugosa

Dip and strike?! We don't need no stinkin' dip and strike!

This blue tongue lizard was clearly not fooled by the request to take a dip and strike on an outcrop of late Neoproterozoic cap carbonate in the Flinders Ranges. He was also clearly unimpressed with the fact that he was standing at the end of the 'Snowball Earth' and the start of the Ediacaran Period. There's just no pleasing some lizards!

The fat tail shows that he was in good condition as that's where they store their fat reserves.

Blue tongues, shinglebacks, or sleepy lizards, as they are commonly known, are members of the skink family (Scincidae).

Saturday, October 10, 2009

The Cambrian Explosion, the Discovery Institute, and the Smithsonian

I intend to write a set of blog posts addressing the comments and thoughts on Darwin’s Dilemma from people who have seen the film. This is useful because people who do not have a background in the Cambrian Explosion or palaeontology are the people that the Discovery Institute is hoping to mislead. So what such people are taking away from the film, the messages that the Discovery Institute is hoping to instill, the questions raised in people’s minds, etc., are worth addressing.

Previous posts: The Cambrian Explosion, the Discovery Institute, and
Charles Doolitte Walcott (part 2)
James Valentine
Prof Paul Chien
Cambrian Ediacaran Extiction
Cambrian Diversity
Charles Doolittle Walcott

The California Science Center in Los Angeles was scheduled to show Darwin's Dilemma of October 25th, but has just announced that it has cancelled the performance. The Discovery Institute is making the usual claim of censorship, and that the cancellation was due to the Smithsonian putting pressure on the California Science Center. The Smithsonian? Well yes, the Smithsonian. But to understand this you have to understand the Discovery Institutes tactics here.

This is all part of the Discovery Institute's desperate attempt for legitimacy through the tactic of 'legitimacy via association'.

This operates by having recognised scientists in you product (even if you have to mislead them into appearing, and they do not support the claims of intelligent design creationism), showing a product in a museum (Seattle) or other science venue, which, by association, validates the claim that the content is scientific.

In their latest attempt at 'legitimacy via association', the Discovery Institute issued a press release promoting Darwin's Dilemma being shown at the California Science Center in Los Angeles, by referring to the Center as the Smithsonian Institution's west coast affiliate. See the tactic?

'We are showing Darwin's Dilemma at the California Science Center which is THE SMITHSONIAN INSTITUTE'S WEST COAST AFFILIATE! SEE? SCIENCE CENTER! SMITHSONIAN! ARE WE LEGIT OR WHAT?!'

The problem for the Discovery Institute is that this particular dishonest tactic is easy to expose.

Firstly, the claim that the California Science Center is the Smithsonian Institution's west coast affiliate. Is it? Actually, while it is a west coast Affiliate, it isn't the west coast Affiliate. The Smithsonian is currently affiliated with 20 fine Californian institutions:
  • Aerospace Museum of California - McClellan
  • Agua Caliente Cultural Museum - Palm Springs
  • Arts Council for Long Beach - Long Beach
  • Blackhawk Museum - Danville
  • California Science Center - Los Angeles
  • Cerritos Library - Cerritos
  • Chabot Space and Science Center - Oakland
  • Discovery Science Center - Santa Ana
  • Fresno Metropolitan Museum of Art and Science - Fresno
  • Hiller Aviation Museum - San Carlos
  • Japanese American National Museum - Los Angeles
  • LA Plaza de Cultura y Artes - Los Angeles
  • Mexican Heritage Plaza - San Jose
  • Millard Sheets Center for the Arts at Fairplex - Pomona
  • Museum of Latin American Art - Long Beach
  • Riverside Arts and Cultural Affairs Division, Riverside Metropolitan Museum - Riverside
  • San Diego Air and Space Museum - San Diego
  • San Diego Natural History Museum - San Diego
  • Sonoma County Museum - Santa Rosa
  • Western Center for Archaeology and Paleontology - Hemet
But lets look further up the west coast, north to the State that flies on her own wings. Any Smithsonian Affiliates there? Well yes,
  • Evergreen Aviation and Space Museum - McMinnville
But wait there's more west coast to go. Up to the Evergreen State. Any Smithsonian affiliates there? (you know the answer, right?)
  • Whatcom Museum of History and Art - Bellingham
  • The Museum of Flight - Seattle
  • Wing Luke Asian Museum - Seattle
  • Northwest Museum of Arts and Culture - Spokane
Hang on. Say what? Two in Seattle?! Isn't the Discovery Institute headquartered in Seattle? They missed two Smithsonian Affiliates right there in their home town?! Oops.

All in all, 25 Smithsonian Affiliates on the west coast.

OK, that's exposes the falsehood of the claim that the California Science Center is the Smithsonian Affiliate on the west coast, but what about the affiliate link anyway, what does that mean?

Clearly the Discovery Institute would want you to think that Affiliates are the Smithsonian in the regions, but what is an Affiliate?
Smithsonian Affiliations offers broader opportunities than those found in standard museum loan programs. In addition to artifact loans, Smithsonian Affiliations helps member organizations identify appropriate resources within the Smithsonian to accompany exhibit loans: education and performing arts programs, expert speakers, teacher workshops, and technical assistance.
So Affiliates are entirely independent from the Smithsonian, and being an Affiliate simply means that they can gain access to the Smithsonian collections to support their own exhibitions. The Smithsonian has no control over the day to day operations of any Affiliate.

So, the California Science Centre is just one of 25 Smithsonian Affiliates on the west coast, and being an Affiliate simply means you get access to the Smithsonian collections, and the Smithsonian has no day to day control over Affiliates.

All this may appear to be nitpicking, but this slight of hand (or in this case slight of phrase) is the modus operandi of the Discovery Institute's dishonest tactic of 'legitimacy via association'.

Of course there would be no need of the tactic of 'legitimacy via association' if your claims weren't scientifically vacuous, but this is the Discovery Institute.

Monday, October 5, 2009

The Cambrian Explosion, the Discovery Institute, and Charles Doolittle Walcott (Part 2)

I intend to write a set of blog posts addressing the comments and thoughts on Darwin’s Dilemma from people who have seen the film. This is useful because people who do not have a background in the Cambrian Explosion or palaeontology are the people that the Discovery Institute is hoping to mislead. So what such people are taking away from the film, the messages that the Discovery Institute is hoping to instill, the questions raised in people’s minds, etc., are worth addressing.

Previous posts: The Cambrian Explosion, the Discovery Institute, and
James Valentine
Prof Paul Chien
Cambrian Ediacaran Extiction
Cambrian Diversity
Charles Doolittle Walcott

I wrote some initial comments on this topic here, but I’ve got a more detailed account of this particular piece and things make a little more sense. I’ll include the relevant sequence and add notes to expose the falsehood and deception.

Also, note that Stephen Meyer and Paul Nelson (like Prof Paul Chien) have no background in palaeontology or palaeobiology, nor apparently in the history of geology.
Stephen Meyer:'Like Darwin, Walcott thought that the Cambrian explosion was an illusion. He was convinced that the fossils were there. They were just inaccessible to scientific discovery. And he expected that they would eventually be found someplace buried deep beneath the oceans.'
Wow, a correct summary by Stephen Meyer! Yes, Walcott thought that the Precambrian sediments with fossils would be found far out to sea for the reasons stated here. He named the period of non-deposition on the continents at this time the Lipalian.
Narration: 'For decades, Walcott’s hypothesis was widely accepted, but untestable. However, later in the 20th century, new technologies [ocean oil platform] led to empirical conclusions.'
Nice of Stephen Meyer and Paul Nelson to pass the lie to the narrator rather than tell it themselves.

No, Walcott’s idea was not widely accepted at the time, let alone for decades. It was quietly forgotten:
He [walcott] suggested that a widespread unconformity at the top of the Proterozoic represented an interval oftime, the Lipalian, in which such an earlier fauna developed elsewhere, but was not recorded in any outcrop. The concept of naming a gap to represent a major missing segment of geologic time, did not result in any comment from the geologic community and the Lipalian Interval vanished (Yochelson 2006)
In the meantime people were finding Precambrian fossils right here on land, oblivious to the fact that they were supposed to be looking for them way out to sea:

Glaessner, M (1959) Precambrian Coelenterata from Australia, Africa and England. Nature. 183. P.1472-1473.

Ford T.D. (1958) Precambrian fossils from Charnwood Forest. Proceedings of the Yorkshire Geological Society. 31. P.211-217.
Stephen Meyer: ‘Once the oil companies started to drill offshore, they brought up what are called drill cores, and inside the core were hunks of sedimentary rock, and some of those rocks contained fossils. But none of them were made by animals that lived before the Cambrian explosion.’
This is an attempt to pretend that geologists were hoping to find Precambrian fossils in drill core. But the idea is nonsense, since it had been known for a long time that there were no Precambrian rocks out to sea and besides, people do not as a general rule drill Precambrian rocks for oil. Almost all offshore oil wells bottom out well before any Precambrian rocks are reached, so we wouldn’t expect to see Precambrian rocks, let alone fossils.

Besides, oil drilling is too close inshore to be useful. Real deep sea drilling didn’t take place until the 1980s, with the the Joint Oceanographic Institutions for Deep Earth Sampling Ocean Drilling program.
Narration: ‘Since the 1960s, scientists have also used radioactive minerals and evidence of changes in the earth’s magnetic field to analyze and date undersea sediments. From extensive surveys they have created this digital map that defines the age of the sea floor.’
Correct, which is why geologists were not hanging out for drill core to find Precambrian fossils. They already knew that the sea floor was too young. The Discovery Institute can’t have it both ways – hanging out for drill core at the same time as knowing the sea floor was too young.
Stephen Meyer: ‘We now know that the oldest rocks on the bottom only date back to the Jurassic period, which means that on the standard geologic time scale, they’re hundreds of millions of years younger than the rocks below the Cambrian strata.’
"We now know"? "We NOW know"? Stephen, we knew 40 YEARS ago! Again, the Discovery Institute can’t have it both ways – hanging out for drill core at the same time as knowing the sea floor was too young.
Paul Nelson: ‘If you are looking for the ancestors to the Cambrian groups, the last place you would expect to find them is out somewhere on the sea floor. Those rocks are much too young.’
Well gee Paul, we’ve known that for 40 years, and have had Precambrian fossils on land for over 50 years, but thanks for pointing that out.

OK, it is clear now that the Discovery Institute is trying to lay the groundwork for Intelligent Design creationism by trying to paint geologists as holding onto Walcott’s Lipalian idea as the only hope to explain the lack of Precambrian fossils.

Their version of events does not tally with reality, but then this is the Discovery Institute.

Yochelson, E.L. (2006) The Lipalian interval: A forgotten, novel concept in the geologic column. Earth Science History. 26(2), p.251-269

The Cambrian Explosion, the Discovery Institute, and James Valentine


Professor Valentine has endorsed the use of his statement on this site.

I intend to write a set of blog posts addressing the comments and thoughts on Darwin’s Dilemma from people who have seen the film. This is useful because people who do not have a background in the Cambrian Explosion or palaeontology are the people that the Discovery Institute is hoping to mislead. So what such people are taking away from the film, the messages that the Discovery Institute is hoping to instill, the questions raised in people’s minds, etc., are worth addressing.

Previous posts can be found here, here, here, and here.

Dr James Valentine appears in Darwin's Dilemma and has released a statement regarding his participation.

24 September 2009

What James Valentine Really Thinks About Evolution

Dr. James Valentine, an evolutionary biologist and Professor Emeritus in the Department of Integrative Biology at the University of California at Berkeley, is featured in the intelligent design movie Darwin’s Dilemma.

I wish to clarify my role in the new film Darwin’s Dilemma. When I was interviewed about a decade ago for the material used in this movie, I was unaware that this interview might appear in a film promoting intelligent design. My appearance should not be misconstrued as support for any creationist agenda.

I support evolution.

I disagree with the view that the best explanation for the Cambrian record is the action of an “intelligent designer” instantaneously creating phyla. Had the filmmakers bothered to read my book On the Origin of Phyla, they would have understood that I do not support a creationist interpretation of the Cambrian explosion or the fossil record. Scientific findings in many fields, including my own (paleobiology) as well as geology, geophysics, geochemistry, developmental biology, and systematics, have led to a synthesis of the events surrounding the Cambrian explosion that is in full accord with well-established evolutionary principles.

When watching Darwin’s Dilemma, I ask viewers to note:
  • My interview statements do not criticize evolution
  • My interview statements do not promote creationism or intelligent design
  • Even though my interview is interspersed with several intelligent design advocates, I do not share their interpretation of the Cambrian record
I would like viewers to know:
  • I think evolution is the best scientific interpretation of the fossil record
  • While the religious views of individuals should be respected, scientists also merit respect earned by generations of hard work in their fields.
Dr. James Valentine
University of California,

Apparently the film makers also forgot to tell Simon Conway Morris (who also appears in the film) the true reason for the interview and intent of the film.

So the experts on palaeontology and palaeobiology that appear do not support the central creationist tenet of the film, which is why, of course, they have Prof Chien as the spokesperson - someone with no background in palaeontology or palaeobiology.

What is it with creationism film makers and their inability to tell the truth about their intentions?

Sunday, October 4, 2009

The Cambrian Explosion, the Discovery Institute, and Prof Paul Chien

I intend to write a set of blog posts addressing the comments and thoughts on Darwin’s Dilemma from people who have seen the film. This is useful because people who do not have a background in the Cambrian Explosion or palaeontology are the people that the Discovery Institute is hoping to mislead. So what such people are taking away from the film, the messages that the Discovery Institute is hoping to instill, the questions raised in people’s minds, etc., are worth addressing.

Previous posts can be found here, here, and here.

This post is in response to Ian’s comments here, and addresses the presence of Prof Paul Chien as a 'spokesperson' for the Early Cambrian Chinese fossils.

Ian Writes:
Paul Chien is a marine biologist at the University of San Francisco and Discovery Institute fellow. According to the USF website, “Prof. Chien is interested in the physiology and ecology of inter-tidal organisms. His research has involved the transport of amino acids and metal ions across cell membranes and the detoxification mechanisms of metal ions”. While the movie presents him as someone who has “done research in the renowned fossil beds of Chengjiang, China”, there’s no evidence to suggest that Chien is a palaeontologist or that he has published any of this findings (outside of Discovery Institute publications). In the movie, Chien is shown visiting the Chengjiang site. If you listen carefully to the what is said, it appears that he did so simply as an interested member of the public, not as an involved researcher. But the viewer is left with the distinct impression that he worked at the site. The movie’s website goes further, claiming that “Dr. Chien has done research in the renowned fossil beds of Chengjiang, China”. While this is possible, I saw nothing in the movie that actually supports this assertion.
Ian's not alone. I couldn't find any publications in peer-reviewed science journals by Prof Chien on the Chengjiang fauna. However, I'd be pleased to list them here if anyone knows of any.

It appears that Prof Chien is not a palaeontologist, he has no palaeontology experience, he has done no palaeontological research. Prof Chien is not an evolutionary biologist, nor a paleobiologist.
And Nigel Hughes says, “As far as I know, P.K. Chien is not a paleontologist and has published no peer-reviewed papers in paleontology. He is not a ‘player’ in scientific issues related to the Cambrian radiation”. David Bottjer observed that “Chien has tried to produce straight science papers on the Chengjiang fossils, but so far I don’t believe that there have been any publications. He has a Chengjiang fossil collection . . . but even if he does have a lot of specimens, that is not proof that he has or can do anything scientific with them; lots of amateurs (non-scientist) individuals have large fossil collections. From my interactions with him in China I can say that Chien knows nothing about the science. He is interested in creationist goals. (Forrest and Gross 2005 p. 56)
So why is Prof Chien used?
According to Kevin Padian, curator of the Museum of Paleontology and professor of paleontology and evolutionary biology at the University of California-Berkeley “Dr Chien admits that he has no expertise or training in paleontology. He admits in interviews that he came into the issue believing that evolution is not true (Forrest and Gross 2005 p. 56)
Prof Chien is also a CSC Fellow of the Discovery Institute, and has translated Phillip Johnson's book Darwin on Trial into Chinese. Prof Chien is the Discovery Institute's spokesperson for Early Cambrian Chinese fossils because noone with actual experience would associate with the Institute and Intelligent Design

Hmm. So having Prof Chien as a spokesperson for Early Cambrian Chinese fossils is kind of like having Orly Taitz as a spokesperson for the legality of the Obama Presidency. No, that’s not fair, at least Orly has legal qualifications, but this is the Discovery Institute.

Forrest, B. and Gross, P.R. (2005) Creationism's Trojan horse: the wedge of intelligent design. Oxford University Press.

The Cambrian Explosion, the Discovery Institute, and Cambrian Ediacaran Extinction

I intend to write a set of blog posts addressing the comments and thoughts on Darwin’s Dilemma from people who have seen the film. This is useful because people who do not have a background in the Cambrian Explosion or palaeontology are the people that the Discovery Institute is hoping to mislead. So what such people are taking away from the film, the messages that the Discovery Institute is hoping to instill, the questions raised in people’s minds, etc., are worth addressing.

Previous posts can be found here and here.

This post is in response to Ian’s comments here, and addresses what appears to be a misrepresentation of the Ediacaran fauna.

Ian writes:
While the movie spends a lot of time on the Doushantuo microfossils, little is said about the remainder of the Ediacaran fauna. They’re basically characterised as outliers, unusual organisms that bear little relation to the groups of organisms present in the Cambrian. And they were said to have disappeared before the beginning of the Cambrian.
So the Ediacaran fauna became extinct prior to the Cambrian. Anyone want to bet that the Ediacaran fauna became extinct before the Cambrian? Anyone? Anyone want to put their money where the Discovery Institute’s mouth is? Anyone? No? Aww . . . you people are no fun. Either that or you’ve learned about the Discovery Institute.
Ediacara-type fossils are rare in the southwestern United States, and Cambrian occurrences of soft-bodied Ediacaran-type fossils are extremely rare. We report both discoidal and frondlike fossils comparable to Ediacaran taxa from the western edge of the Great Basin. We describe one specimen of a discoidal fossil, referred to the form species ?Tirasiana disciformis, from the upper member of the Lower Cambrian Wood Canyon Formation from the Salt Spring Hills, California. Two fragmentary specimens of frond-like soft-bodied fossils are described from the middle member of the Lower Cambrian Poleta Formation in the White Mountains, California, and the upper member of the Wood Canyon Formation in the southern Kelso Mountains, California. On the basis of similarities with fossils from the lower member of the Wood Canyon Formation and from the Spitzkopf Member of the Urusis Formation of Namibia, these specimens are interpreted as cf. Swartpuntia. All fossils were collected from strata containing diagnostic Early Cambrian body and trace fossils, and thus add to previous reports of complex Ediacaran forms in Cambrian marine environments. In this region, Swartpuntia persists through several hundred meters of section, spanning at least two trilobite zones. (Hagadorn et al 2000)
Hagadorn, J.W., Fedo, C.M. and Waggoner, B.M. (2000) Journal of Paleontology. 74(4). p.731-740

The Cambrian Explosion, the Discovery Institute, and Cambrian Diversity

I intend to write a set of blog posts addressing the comments and thoughts on Darwin’s Dilemma from people who have seen the film. This is useful because people who do not have a background in the Cambrian Explosion or palaeontology are the people that the Discovery Institute is hoping to mislead. So what such people are taking away from the film, the messages that the Discovery Institute is hoping to instill, the questions raised in people’s minds, etc., are worth addressing.

Previous posts can be found here.

This post is in response to Ian’s comments here, and addresses what appears to be a failure to understand the basics about the environment of deposition of the Burgess Shale and the Chengjiang faunas. This is a bit of a side bar, but does illustrate the modus operandi of the Discovery Institute, which can be described as ‘the Art of the Superficial’
Although the Chengjiang fauna is about 10 million years older than those of the Burgess Shale, it is described as being more diverse. This, the movie argues, narrows the window of time in which these distinct groups of species could have evolved. The shorter the window of time, the less likely it is that these groups would have evolved “by chance”.
OK, to describe the difference in diversity between the two faunas as anything meaningful is to look at the issue purely from a simplistic, superficial view. But then Intelligent Design is a monument to the superficial viewpoint, based as it is on the idea that, ‘gee willikers, that there fla-gell-um looks toooo complex to have e-volved, it must have been de-signed’.

Detailed investigation (i.e. science) is the antithesis of the Art of the Superficial. Detailed investigation blew away the myth that the flagellum was irreducibly complex, and showed that it was similar to a type III secretion system.

Detailed investigation shows that the Chengjiang fauna is more diverse that the Burgess Shale fauna for reasons that have nothing to do with the diversity of life at the time. It is known that the Burgess Shale fauna, while spectacular, is a restricted fauna. It does not represent the breadth of life at the time. The fauna has been washed in over a steep limestone escarpment into deep, oxygen poor, water over 160 metres deep (see for example Briggs et al 1994).

The Chengjiang fauna, while also predominately a washed-in fauna, was positioned in open water at the foot of a delta at around 100 metres deep (see for example Chen and Zhou 1997, Hou et al 2004). A much more open system and so would be expected to sample a greater range of organisms.

One datum point from one location in Chengjiang and Burgess Shale time does not tell us about overall diversity during either time, unless you use the Art of the Superficial.

Briggs, D.E.G., Erwin, D.H. and Collier, F.J. (1994) The Fossils of the Burgess Shale. Smithsonian Institute Press. 238pp.

Hou, X-G; Aldridge, R.J., Bengstrom, J, Siveter, D. J., Feng, X-H (2004) The Cambrian Fossils of Chengjang, China. Blackwell Science. 233pp.

Junyuan Chen and Guiqing Zhou (1997) Biology of the Chengjiang fauna. Bulletin of the National Museum of Natural Science. 10. p.11-106.

Saturday, October 3, 2009

The Cambrian Explosion, the Discovery Institute, and Charles Doolittle Walcott

The Discovery Institute is back with another attempt to legitimize Intelligent Design, this time with a movie on the Cambrian Explosion - Darwin’s Dilemma.

I haven’t seen the film, but given the well documented problems the Discovery Institute and its cohorts seem to have with basic honesty, I’m expecting the usual snow job.

I intend to write a set of blog posts addressing the comments and thoughts on Darwin’s Dilemma from people who have seen the film. This is useful because people who do not have a background in the Cambrian Explosion or palaeontology are the people that the Discovery Institute is hoping to mislead. So what such people are taking away from the film, the messages that the Discovery Institute is hoping to instill, the questions raised in people’s minds, etc., are worth addressing.

This post is in response to Ian’s comments here, to address what appears to be a misleading section in the film regarding Charles Doolittle Walcott (the discoverer of the Burgess Shale) and alleged contemporary geological ideas as to the whereabouts, and lack, of Precambrian fossils.

Ian writes:
According to the movie Walcott (the discovered of the Burgess Shale) suggested that the transitional Precambrian fossils might be found beneath the ocean floor. I have no idea whether this was a serious prediction or not, but the movie treats it as if it were. They say that Walcott’s hypothesis remained untested until deep-water drilling for oil has brought lots of drill cores from the bottom of the ocean, and none have revealed Precambrian fossils. They then go on to say that ocean-floor mapping has revealed that the rocks of the ocean floor are relatively young, and the ocean floor is an entirely unsuitable place to look for Precambrian fossils.
So is this correct? Well, the first part is – but needs some clarification (surprised?), but the rest is pure bollocks.

Firstly did Walcott suggest that Precambrian fossils would be found beneath the ocean floor? Well, yes he did, but deep under the ocean, not necessarily deep under the ocean floor. This was in response to his being unable to find Precambrian fossils.
I have for the past 18 years watched the geological and paleontological evidence that might aid in solving the problem of Precambrian life. The great series of Cambrian and Precambrian strata in eastern North America from Alabama to Labrador in western North America from Nevada and California far into Alberta and British Columbia, and also China, have been studied and searched for evidences of life until the conclusion had gradually been forced upon one that on the North American continent we have no known Precambrian marine deposits containing traces of organic remains, . . . (Walcott 1910, p.2)
To explain this Walcott suggested that the Precambrian continents were much greater in extent than the present, or even the Cambrian, continents, and so the Precambrian ‘coastlines’ – and hence shallow water marine sediments to look for fossils – were much further out to sea compared with the current coastline. In other words, the current continents are the centres of the Precambrian continent and represent
. . a period of continental elevation and largely terrigenous sedimentation in non-marine bodies of water, also a period of deposition by aerial and stream processes over considerable areas (Walcott 1910, p.4)
Walcott hypothesized a much larger Precambrian continent to account for the lack of marine Precambrian sediments because he was working in a time before the theory of plate tectonics revolutionized our understanding of continental processes. In Walcott’s time the continents were considered stationary, and so a lack of sediments represented a period of uplift and wider continents, whereas the presence of marine sediments represented a period of subsidence and seas inundating the margins of the continents.

So Walcott considered that the margins of the Precambrian continent were much further out in the oceans that the present continental margin, and hence the shallow marine sediments with Precambrian fossils would be found under the deep ocean. This period of unknown marine sedimentation was named the Lipalian period. But Walcott’s hypothesis and the Lipalian period was short lived.

Which brings up to the second claim, that Walcott’s hypothesis remained untested until deep-water drilling for oil has brought lots of drill cores from the bottom of the ocean, and none have revealed Precambrian fossils.

Say what?!

Umm, Walcott’s hypothesis of the Lapilian period of non-deposition was largely ignored,
Despite Walcott's diligent search, hardly any fossils were found in these older strata, and those discovered did not assist in biostratigraphy. Years later, when attempting to explain the issue of a diverse Cambrian fauna seemingly without any antecedents, Walcott developed a hypothesis to explain the absence of earlier fossils based on geological, rather than biological, features. He suggested that a widespread unconformity at the top of the Proterozoic represented an interval oftime, the Lipalian, in which such an earlier fauna developed elsewhere, but was not recorded in any outcrop. The concept of naming a gap to represent a major missing segment of geologic time, did not result in any comment from the geologic community and the Lipalian Interval vanished. (Yochelson 2006)
Walcott was doing science. He had observations – apparent lack of marine Precambrian sediments – and produced a hypothesis to account for them. But the hypothesis was not taken up. It was, however, tested, albeit indirectly.

By the late 1950 and early 1960’s the theory of sea floor spreading was becoming well established and by the end of the 1960 it was shown that the ocean floor was younger than Precambrian through measuring the magnetic striping caused by magnetized lava formations (see for example Heirtzler 1968). See floor spreading and plate tectonics rendered any vestige of Walcott's hypothesis redundant.

So, far from waiting until deep sea coring (not incidentally related to oil exploration, but to the Joint Oceanographic Institutions for Deep Earth Sampling, Ocean Drilling program in the mid 1980’s), it has been well known that there are no Precambrian rocks awaiting discovery under the deep oceans for at least 40 years.

But the Discovery Institute film also neglects the fact that fossil-bearing marine Precambrian rock had been discovered before this: Charnwood Forest, England (Ford 1958); South Australia and Namibia (Glaessner 1959); and subsequently from Canada, Russia, and the USA.

To suggest that Walcott's hypothesis wasn't tested, or that palaeontologists were somehow hanging out for deep sea cores to provide Precambrian fossils, is laughable, but this is the Discovery Institute.

Ford T.D. (1958) Precambrian fossils from Charnwood Forest. Proceedings of the Yorkshire Geological Society. 31. p.211-217

Glaessner, M (1959) Precambrian Coelenterata from Australia, Africa and England. Nature. 183. p.1472-1473.

Heirtzler, J.R. Sea Floor Spreading. Scientific American, December 1968, p.60-70.

Walcott, C.D. (1910) Abrupt appearance of the Cambrian fauna on the North American Continent. Cambrian Geology and Paleontology II. Smithsonian Miscellaneous Collections 57. p.1-16.

Yochelson, E.L. (2006) The Lipalian interval: A forgotten, novel concept in the geologic column. Earth Science History. 26(2), p.251-269.

Tuesday, September 29, 2009

Vale Troy Kennedy Martin

On 15 September, Troy Kennedy Martin died of liver cancer.

He wrote two movies Kelly's Heros and The Italian Job (the proper one with Michael Cane, not the pale imitation). But for me he is best remembered as the writer of the ground-breaking 1985 BBC TV drama Edge of Darkness. Also known for it's music score co-written and played by Eric Clapton (see below), Edge of Darkness marked the beginning of real political drama on the BBC.

If you've never seen it, do yourself a favour, get a copy, shut the curtains, turn off the phone and settle down for 5 hours of the best TV drama you are ever likely to see.

Tuesday, September 8, 2009

Livelife 2

Hi Ho. Hi Ho. It's off to work we go . . .

Geologists always walk around looking at the ground because that's where the rocks are. Especially in a creek bed in the middle of a gorge in the Flinders Ranges. Occasionally you see something else of interest.

This group boldly heading out along the floor of the gorge took me by surprise because, although there are several species of butterflies and moths native to the Flinders, I'd never seen caterpillars there before (click on the image to enlarge). The ripples in the creek bed can clearly be seen, and the trail of caterpillars almost mimics the rise and fall of the ripples. The lens cap is 52mm in diameter

Tuesday, August 18, 2009

2010 Atheist Global Convention

The 2010 Atheist Global Convention will be held down under in Melbourne. Speakers include Richard Dawkins and Philip Adams.

They are currently taking expressions of interest to estimate numbers, so go over to the site and express yours. Oh yeah, someone called PZ Myers will also be there.

The Wilkins will also probably be there. He will even sign his book if you ask him.

Sunday, August 16, 2009

Badges Wot I Have Earned

Go over to science scouts and check out how many you've earned.

Troop Badge. This is a natural. I woz a geologist therefore I drank.

The talking science badge. Another easy one. used to be on Talk.Origins, and just this week regailed co-workers with the fact that swine flu is long and thin and not spherical (thanks to ERV)

The “Nyah nyah nyah nyah nyah, I’ve got a TV gig” badge. The latest one is here.

The “I blog about science” badge. Well duh!

The “destroyer of quackery” badge. I spent way too much of my academic life on the Talk.Origins newsgroup.

The “I can be a prick when it comes to science” badge. Just ask the geology mapping student groups I used to lead. "No we will not be using the formation names so you can cheat by looking up the geological maps" - bastard!

The “inordinately fond of invertebrate” badge. Not many vertebrates in the Ediacaran and Lower Cambrian. Besides, many say it was a mistake to come down from the trees, some say the move out of the oceans was a bad idea. Me, I say the stiffening of the notochord in the Cambrian was where it all went wrong, it was all downhill from there.

The “respect me - I’ve published at an upper tier publication for popular science readership” badge. This is a bit tricky as I don't know the circulation figures, but I nominate the journal Geology and this paper.

The “have used a dental drill and I’ve never been a dentist” badge. Used to clear matrix away from fossils - WEEEEEEEEEEEEEEEEE. Used for several years with no ill effects. What? WHAT? YOU'LL HAVE TO SPEAK UP . .

The “science has forced me to seek medical attention” badge. Well there was 10 kilos of fossils in the backpack, a trail bike and a sheep. Please I don't like to talk about it. Can you say Bennett's Fracture?

The “has done science whilst under the influence” badge. In geology, the most productive field work is done after dark under the influence of alcohol and a raging fire.

The “science deprives me of my bed” badge (LEVEL III). Got this one easy with field work in the Flinders Ranges and on Kangaroo Island.

The “rock licker” badge. Still the best way to tell claystone from siltstone.

13, and there are a couple of ones I could have gone for. I beetz the ethical palaeontologist who still is a palaeontologist! I don't think she's really trying . . .

Thursday, August 6, 2009

Sam the Koala dies

Sadly, Sam the Koala was put to sleep at 1.00 pm this afternoon.

She was supposed to undergo surgery for abdominal cysts associated with chlamydia. However, the vet treating Sam found that her condition was worse that thought, with inoperable damage to her urinary and reproductive tract. As she was in considerable pain, it was decided to put Sam to sleep.

Sam the Koala - a turn for the worse

Sam the Koala, rescued from the Victorian bush fires earlier this year and famous for taking a drink from a passing fire fighter, will under go a serious operation today (Thursday), and the prognosis is not good.

Sam has been diagnosed with abdominal cysts associated with urogenital chlamydiosis. This is not associated with the injuries Sam received in the fire, from which she has been making a good recovery.

Urogenital chlamydiosisa is, unfortunately, a common disease amongst Koalas and can be fatal, hence the decision to operate.

The people treating Sam are not optimistic for her survival.

Monday, August 3, 2009

Religion in Australian Politics

There is an opinion piece in today's Australian Financial Review by Geoffrey Barker, visiting fellow at the Strategic and Defence Studies Centre at the Australian National University, about religion in Australian politics. It's behind a fire wall, and much of it relates to specific Australian examples, but some is of general interest and is excerpts are provided below.

It is time Australians paused to consider the possible adverse consequences of unleashing the politics of faith on the essentially secular activity that is democratic politics. They include intolerance, authoritarianism and poisonous social division.

Some religious teachings are doubtless important in informing some political views. But allowing political conflict to be expressed as clashes of secredly ordained beliefs rather than of socially acquired interests is a recipe for non-negotiable disputes that defy the necessary compromises of political life.

A democratic society should respect the faith-based commitments of citizens; it should respect their views of religious leaders on contentious issues like abortion, censorship and social justice. It should also respect the views of non-believers.

What it cannot do is concede that any faith group possesses a monopoly on truth and virtue and allow it to impose its attitudes on the entire society. Politics arises from diversity; to eliminate diversity is to legitimise authoritarianism.

It is not necessary to have religious convictions to be tolerant and compassionate and to observe high standards of moral responsibility. Indeed, so-called humanists (much maligned by religious authoritarians) can reasonably claim to have views grounded in logic and experience rather than in rules revealed by divine intervention.

Tolerance to opposing views, and the willingness to accommodate them, are defining characteristics of democratic politics that are anathema to religious fundamentalists.

[. . .]

Sadly many Australians seem willing to swallow uncritically the religious avowals of politicians. Yet it is hardly cynical to conclude such politicians often use religion opportunistically to advance their political careers.

Moreover, those seriously demanding spiritual virtues have absolutely no appeal to politicians pursuing personal glory and earthly power.

Sunday, August 2, 2009

RU486 approved in Italy

The BBC is reporting that the drug RU486 has been approved by the Italian Pharmaceuticals Agency for use in Italy.

Nothing special about a state pharmaceuticals agency approving a drug for use, except this is Italy and RU486 is otherwise known as the morning after pill, or the abortion pill.

RU486 available in Italy! Wow!

Kudos to the Italian Pharmaceuticals Agency, who in a 4-1 decision to approve, stated that "the task of protecting the well-being of citizens ... must take precedence over personal convictions."

The drug will not be available over the counter, but will only be available in hospital under the supervision of a doctor.

The Catholic Church has, of course, come out strongly against the decision. They could not threaten the Italian Pharmaceuticals Agency directly to influence the decision, as that's, like, illegal. So it's done the next best cowardly thing. The Vatican has threatened to excommunicate any doctor, nurse, or woman involved in taking RU486.

Well done the Italian Pharmaceuticals Agency. Another small step in removing the Catholic Church from women's uteruses

Thursday, July 9, 2009

Blogging "the Ediacaran Biota"

The Radio 4 program "In our Time" is running a program on "the Ediacaran Biota". I'm blogging this as initial thoughts right after the program. It can be heard here.

Oh dear. The photo that accompanies the show on the web site (shown here on the right) has a Dickinsonia costata, but it is upside down! The large segments are considered the head end. So this Dick is doing a head stand!

And it's bad start as they can't pronounce the name correctly. They are pronouncing it "Edi-aaa-car-raaan with long 'a' sounds. It's not pronounced like that. The term is an indigenous Australian word which is pronounced Edi-ak-ra, with the last 'a' pronounced like the last 'a' in Russia, and the middle 'a' not pronounced at all, or Edi-ak-ran with 'ran' pronounced as in "he ran away". All the 'a' sounds are harsh and short. The name means "reedy waterhole'" (Edi- means waterhole).

Ony one of the three guests has worked on Ediacaran fossils, and there are no Australians - they might have got at least one on the phone!

OK, there is a lot of talk about how the appearance of shelly fossils in the Cambrian is sudden, and that this was a problem for Darwin. This is misleading.

It has to be put in context.

The early mapping of what was recognised as the Cambrian rocks (from the name of the Latin name for Wales, where the section was mapped) and became the "Type Section" (the reference section agains which all other sections of the same age around the world are compared), did show that there was a rapid transition from 'barren' 'pre-Cambrian rocks to fossiliferous Cambrian rocks, replete with trilobites, sea shells and other relatively complex organisms.

This rapid transition is what they are talking about, and was the one familiar to Darwin - he actually traversed these Cambrian rocks with the Reverent Adam Sedgewick (who named the Cambrian Period and who was well aware that this represented the earliest evidence of life in the fossil record).

The important point here is that, yes fairly complex fossils appear quite abruptly in this rock section, BUT, the section is incomplete. Basically the section is missing a good deal of the earliest Cambrian rocks. In other words the basal rocks containing the emergence of the Cambrian biota are missing from this area. It's like starting a book at chapter 3 - the introductory chapters have been ripped out at this place.

Rock sections in other places around the world which contain the earliest Cambrian rocks, show a transition from trace fossils, to complex trace fossils to small shelly fossils which comprise bits of the armour of larger organisms, to full body fossils.

This transition has a lot to do with the acquisition of hard parts by organisms - by the process of biomineralisation, where calcium carbonate and calcium phosphate are incorporated into the outer tissues of organisms to produce hard shells (e.g. crabs do this after they molt).

So yes, Darwin conceded that such a rapid transition to complex fossils was a difficulty for his theory, but we now know that the rapid transition he was referring to is an artifact of an incomplete rock record in that area.

There are several references to the Ediacaran biota appearing right after the last major 'snowball Earth' glaciation in the pre-Cambrian. This is incorrect.

The last 'snowball Earth' glaciation ended about 650 million years ago, the earlest Ediacaran biotas appear some 50 million years after that and, in fact, there is some evidence for intervening glacial episodes - albeit not as extensive as the 'snowball earth' ones.

The answer to the question, "Is the Ediacaran biota a failed experiment?" was answered pretty well. Short answer - no.

Longer answer - they lasted for some 40 million years but the bulk of them were done in by a changing environment which took away the conditions required for their preservation as fossils, and the rise of predation (with the rise of mineralisation of tissues allowing jaw elements to be carbonate tipped). However a few groups survived to pass on their genetic legacy to future groups.

Summary, not a bad show all in all. Recommended if you are interested in the Ediacarans.

Wednesday, July 8, 2009

Ediacara on the Radio

No, not me!

John Wilkins has alerted me to the fact that the subject of the next "In Our Time" Radio 4 (UK) broadcast with Melvyn Bragg will be on "The Ediacara Biota".

The broadcast will be on from 9.00 - 9.45 am (British Summer Time) on Thursday 9th July, and will be repeated at 9.00 pm the same day.

If you miss it, you can listen to it at any time afterward from the same link above.

Thursday, July 2, 2009

"Don't Cry For Me, Anteater . . . "

In the previous post, TamanduaGirl, commented that it looked like the tear duct in the anteater skulls figured was outside the orbit, unlike other placental mamals.

Actually the tear duct is on the inner part of the orbit (where the orbit bone slopes towards the eye). It's difficult to see on a two-dimensional image, but I've enhanced the image below.

In each image, the tear duct is actually the smaller hole (ringed in the lower image) - the larger hole is a nerve opening. In each instance, the duct is positioned just slightly on the inner side of the orbit. The limit of the orbit is indicated with a dotted line in the lower image.

In the image linked to appears to be a cast, and, as such, only shows the larger nerve opening and not the tear duct. Small openings are often missing from casts.

More on monotreme-marsupial-placental evolution soon.

Tuesday, June 30, 2009

And now you don't (again)

In a previous post I talked about the position of the tear duct in placental mammals verses marsupials, and how the duct was outside the orbit in marsupials, but inside the orbit in placentals. Someone asked what was the condition in monotremes, which was a good question. I didn't know the answer and had to wait until a recent trip to Adelaide to be able to access a monotreme skull to find out.

The answer is that, in monotremes, the duct is inside the orbit, just like placentals.
The skull of an Echidna (above) shows the duct to be inside the orbit. In an actual specimen, the duct is placed in the bone surface sloping into the orbit (not clear on a two-dimensional photo). In a marsupial the duct would be clearly visible outside the orbit.

So there you go, only marsupials have the duct visible outside the orbit.

So the question now is, how do you tell a placental anteater skull from an Echidna skull?

The answer is that the Echidna is far more bird-like than the anteater, and the cranium tends to slope sharply downward at the front in the Echidna, but tends to be much flatter in the anteater (see below).

Photo credit
Echidna - University of Washington
Anteater - Natural History Museum, London

Thursday, May 28, 2009

Sam the Koala - latest

Sam the koala, who became famous after the Victorian bushfires for taking a drink from a water bottle of firefighter David Tree, is recuperating well.

Taken to the Southern Ash Wildlife Centre with burns and dehydration, Sam was one of 100 koalas taken in by the Centre. There are now only a few dozen left, including Sam, who has an eye infection, but is expected to be fit enough to be release soon.

Sales of a photo of Sam taking a drink from the water bottle has raised around A$510,000. A$500,000 will go to firefighters who lost their homes in the bushfire, the rest will go to the Centre, to develop a specialist burns unit to treat future burns victims.

Photo credit: the Herald Sun

Sunday, May 24, 2009

Palaeoporn 13

Look up there! Is it a brachiopod? Is it an annelid? Is it a mollusc?

Umm  . . . actually, its a bit of each really.

This is a wiwaxiid from the Emu Bay Shale. Unfortunately undescribed, but closely linked to Wiwaxia and the halkieriids. It would be one of the oldest examples of a wiwaxiid, as the others are from the Middle Cambrian Burgess Shale and comparable deposits.

The beast was bilaterally symmetrical, oval in shape, and covered with short scales - called sclerites. Also present were a number of rows of larger spines which protruded upwards in a probable defensive array (see reconstruction at right)

Wiwaxiids had a flat foot-like underside. Little is known of the internal anatomy.

Wiwaxiids have been classified as molluscs, annelids and stem group annelids (a group closely related to annelids). The spines have been compared to the eltrya, or scales, of polychaete worms, and even bristles of molluscs, annelids and brachiopods, and halkieriids, of course, have little brachiopod shell caps!

One feature found in wiwaxiids is a radula-like feeding bar. So I looked to see if my specimens had a radula-like feeding bar. I've switched to black and white photos for higher resolution. A bar structure, formed of calcium phosphate, was found towards the front of the specimen. After preparing out (lower image) half the bar remained and the other half (the distal, or outer, part of the bar is removed, leaving a mold of the lower surface of the bar. in this mold can be seen several depressions along the 'upper' margin, represented by shadow (the light is coming from the top right of the image). These are 'teeth' which would have protruded from the lower margin of the bar (the bar is approx. 5 mm long.)

So, spines, radula-like feeding bar, seems like a Lower Cambrian wiwaxiid!

Tuesday, May 19, 2009

Now you see it, now you don't

While we are talking about marsupials (see previous post), it's a good time to show how to tell the difference between a marsupial and placental mammal skull - you know for those life or death, save the world, situations when you need to be able to tell the difference. There's nothing like being prepared.

There are a few differences between the marsupial and placental skulls, however the easiest by far is the nasolacrimal duct - that's the tear duct to you and me.

Above are the skulls of a Thylacoleo (left) and a Thylacene (right). The tear duct is clearly visible outside of the eye socket, sitting on the cheek.

Now the skull on the right is a dog skull. See the tear duct?

Oh no, that's right, you can't, 'cos it's not visible. In placentals, the tear duct sits inside the eye socket, and so you would have to view the skull from above and look down into the eye socket to see it. Whereas in marsupials, the duct sits outside the eye socket and is clearly visible when viewing the skull from the front or side.

So the next time you have to make a life or death identification, you can spot the marsupial with confidence.

Saturday, May 16, 2009

My Grandma, what big teeth you have . . .

. . . the fellest and most destructive of predatory beasts (Richard Owen 1859)
Teeth are tough. Which was good for palaeontology, because for a while there, they represented the majority of early mammal remains (not any more thankfully).

Not only are teeth tough - and so preserve well - they are also quite plastic in terms of shape, and so can be diagnostic for evolutionary purposes, and also for palaeoecological purposes, because the shape of teeth can tell us a lot about what the owner ate.

Chiselly front teeth and flat molars suggest a vegetarian diet, while pointy-stabby teeth and slicey-crushy molars indicate a meat-eater (humans have a smorgasbord of different types as befits omnivores - or eat-anything types).

This is all very well and good, but what happens when you come across a unique set of munchers? Ones that have been modified beyond all recognition?

(What? Yes I know, I know, this is Pleistocene vertebrate palaeontology. Why? Well it's like this, I fell off the trail bike during field work, and while recuperating from a fracture bone in the wrist, I did this as part of the course requirement. Please, I don't like to talk about it.)

Presenting Thylacoleo carnifax the "marsupial lion"

Check out Premolar 3 (labeled Pm3 in the image). Premolars are teeth with delusions of molarity, but, even so, these are huge! And have a very sharp blade-structure. No other premolar or molar comes close in terms of shape to Thylacoleo's premolar 3.

Oh yeah, and see the big canine tooth in front of Pm3 in the lower jaw? Umm . . . that's not a canine. It's a heavily modified incisor (the chisel-like teeth in the front of the jaw).

Weird, huh?

When Richard Owen first described Thylacoleo in 1859, he was in no doubt about what it ate, as the quote above indicates. However, this was questioned at the time, especially as Owen had classified Thylacoleo as a diprotodontid, and all diprotodontids were vegetarian.

Indeed, a number of fanciful interpretations of what constituted Thylacoleo's diet followed, including, herbivore, scavenger, soft fruit, cycad pith or the fruit of the Cucurditaceae (that's melons, gourds and cucumbers), even crocodile eggs!

More recent studies have favoured a carnivorous diet, relying on dental wear patterns and skeletal structures. But, is there another way to tell? Well, yes (otherwise this was going to be a very short post).

Introducing Strontium and Zinc.

Both Strontium and Zinc can be used as an indicator of diet.

Sr is discriminated against in the food chain. It is not taken up by vertebrate tissues and organs, but it is taken up in bone, at about 20% of the amount ingested.

Plants, however, do preferentially take up Sr, with leaves and other herbaceous vegetation taking up higher levels than grasses.

This unequal distribution means that browsing herbivores are exposed to, and thus take up, more Sr than grazing herbivores, and both are exposed to more Sr than carnivores.

Zn is the reverse. It is found in blood and tissues, but less in plants, with herbaceous plants having the least.

There are some caveats to using this type of analysis. Only bones from the same location can be compared, as background Sr and Zn levels vary from place to place; only adult bones are used (juvenile bones show markedly reduced Sr levels as mammalian milk is very low in Sr); and teeth and rib bones are not used - Sr levels in teeth are not reset with age, and rib bones are metabolically active and could be susceptible to short term resetting (especially during lactation).

So that's the theory, but does it work?

A number of bones from a variety of adult animals were collected from Henschke Cave at Naracoorte, South Australia (depost 35-40,000 years old). These were the grazers, two kangaroos (Macropus giganteus), a rat kangaroo (Potorous tridoctylus), and a wombat (Vombatus ursinus); the browser, a koala (Phascolarctos cinereus); a ?mixed browser/grazer, a short-faced kangaroo (Sthenurus sp.), and insectivore/carnivores, a long nosed bandicoot (Perameles gunii), two Tasmanian tigers (Thylacinus sp.); and of course Thylacoleo carnifex.

These bones were analysed and the results (in parts per million) were as follows:

The koala was clearly differentiated, with the highest Sr and lowest Zn, confirming it's status as a browser.

Plotting between the koala and grazers (kangaroos, rat kangaroo, and bettong), was Sthenurus, which was pleasing as it has been interpreted as a mixed feeder, based on its morphology. This analysis supported that interpretation.

Within the grazers, the outlier is the wombat. It's higher levels of Sr and Zn may be due to its burrowing lifestyle, where it is exposed to fine dust which could increase its exposure to Sr and Zn. Taking the ratio of Sr to Zn, however, the wombat clusters with the other grazers.

The insectivores/carnivores cluser to the right of the graph with low Sr but elevated Zn.

All samples had much higher levels of both Sr and Zn than the matrix, so matrix levels were not influencing the results.

So, where does Thylacoleo fit?

Thylacoleo (in red) plots right in the carnivore end of the spectrum, supporting that it is indeed, a carnivore.

This means that Owen was right, and that this is an extraordinarily rare case of a veg-head group producing a carnivore.

This is why the teeth are so weird. The 'canine' is formed from an incisor because the group did not have canines. Premolar 3 is weird because the group did not have carnivorous premolars and molars with slicing edges, and so Pm3 had to evolve from an herbivorous premolar.

Photo credit - Thylacoleo skull photo from Brian Switek's Laelaps blog.

Friday, May 8, 2009

A Rave of Locusts

Your average locust is actually solitary beast who will actually shun other locusts. So the question is, why does a solitary animal suddenly turn gregarious with such a vengeance that it turns into a super organism that causes huge devastation?

A recent Catalyst program looked at the work done on this by a joint Cambridge and Sydney team. It appears that if the hairs on the back legs are stimulated (through contact with other locust - or a paint brush in this instance) for several hours, the locust turns from a loner to gregarious.

This short time frame meant that the cause of the the change had to be chemical, and not through a re-wiring of the nervous system.

When they studied gregarious locust they found that they has elevated levels of serotonin.

Serotonin is found in the human brain, and low levels are associated with depression. Prozac works by increasing serotonin levels. High levels of serotonin are associated with happiness. This is how Ecstasy works.

But there's something else going on. The swarming doesn't happen until there is a critical mass of locust. Then they all start moving in the same direction.

So strong is the urge to move together, that any that do not are set upon and eaten by the others.

So it looks like locusts invented the rave party long before humans.

Now that the chemical that triggers the gregarious behaviour has been found, a solution presents itself.

The only trouble is, how do you persuade several million drugged-out locusts to drink a glass of warm milk and have a good lie down?

Michael L. Anstey, Stephen M. Rogers, Swidbert R. Ott, Malcolm Burrows, and Stephen J. Simpson. . Science 30 January 2009 323: 627-630 [DOI: 10.1126/science.1165939]

Sunday, May 3, 2009

Swineflu jokes

I don't know where this came from, so I can't credit it, but it's bloody funny!

Sunday, April 19, 2009

Livelife 1 - Nephila edulis

As a counterpoint to the deadlife that usually populates this blog, I'll be posting some images of livelife that has occasionally interrupted the search for said deadlife.

Nephila edulis, or the golden orb weaver, (click image to enlarge) is common throughout the Flinders Ranges, and is an FBS, where the B and S stand for Big Spider. This one is about 15 cms (around 6 inches) in total length. The female always builds the web, as the males generally live on the periphery of her web and are usually about 1 cm (0.5 inch) long. She will sit in the centre, next to her tube of spoils, maintaining contact with the web, ready to pounce on anything unlucky enough to get trapped, and bring it back to her tube of spoils.

As befits a FBS, she builds a FBW where the B and W stand for Big Web. The central web is 120+ cm (4+ ft) long, and usually stretches across a clearing between two large bushes. In other words right across where you would normally walk. In other words right across where you would normally walk while looking down at the ground (because you are a geologist and the ground is where the rocks are).

If you are lucky, the centre of the web is at chest height, or above head height.

If you are lucky.

You aren't always lucky.

However, the local name for them is "drop-off spider" because, if you are unfortunate enough to encounter a web, the spider will generally drop off the web, or you, rather than bite (they have small jaws anyway and on the rare occasion that they bite, the results are not too bad).

Very polite of them considering the amount of work that went into the structure you have just destroyed.

The web framework is incredibly strong and will actually resist breaking, so you are in no doubt that you have just encountered one.

Wednesday, April 15, 2009

The World's Oldest Poo

You can learn a lot from poo.

Fossil poo, or coprolites, can provide valuable information on the size and feeding habits of the organism that produced them.

Large Cambrian coprolites are rare, and tend to be circular, but one found in the Lower Cambrian Emu Bay Shale was different.

Before going further, you should look at this short TV story that was done last year. It puts the poo in context, and the poo has a small cameo.

Keeping with the theme of using black and white photography to show critical features that may not be apparent in colour (in Palaeoporn 12), I have a black and white image of the poo. But before that I need to show you some features of Redlichia highlighted in the following image (click to enlarge).

Now pay attention as there'll be a test later. The left hand image shows a complete Redlichia. The feature in the blue box is a thorasic spine. Redlichia had a number of these attached to a number of axial rings, which comprises the central ridge. The central image shows a close up of the tip of the segment in the yellow box, showing the tip of a depression in the segment, or pluron, called the plural furrow. The right hand image shows the head region of a large Redlichia. Around the whole of the outer margin of the head is a thick zone with terrace ridges (in the red boxes) that are common in Redlichia. (Incidentally the structure coming off the head at one of the red boxes, is an antenna).

Ok, now for the image of the poo (click to enlarge).

The lower image has been augmented to delineate the poo and to highlight certain features.

Firstly the size. it's 43 mm in length and has a maximum width of 28 mm. It is formed of two 'layers' an upper diffuse layer, probably representing a fluid phase that has expanded outward. The lower layer is coarse particulate layer is crammed with trilobite fragments. If you compare the boxed areas of the poo with the three part image above (colour coded for your convenience), you should be able to make out just which parts of the ex-trilobite are represented here. The whole of the lower part of the poo is trilobite hash!

The poo tells us what was being eaten. The thorasic spine, plural tips and terrace lines present identify the remains as that of a Redlichia.

The poo tells us the size of what was being eaten - about 4 cm in length.

The poo tells us how it was being eaten. The fragments are broken. They are not crushed. They are not nibbled. They are not gnawed. They are not bitten. This means that the trilobite was broken up and not bitten (see CSI-Cambrian).

The poo tells us the size of what was doing the eating. Assuming the trilobite hash layer represents the true original thickness of the poo is 15 mm. This gives us a terminal alimentary tract of 15 mm, which roughly correlates with a 75 cm body size (from measurements done of other Cambrian fossils).

The poo tells us what was doing the eating. The broken up fragments and the size of the organism suggests Anomalocaris was the perpetrator.

So this one specimen tell us that two particular species were present, which was the predator, which the prey, and the method of predation.

Not bad for a piece of crap!

Monday, April 13, 2009

Religious Ghoul - Down Under Version

Meet Cardinal Pell, leader of the Catholic church in Australia, Religious Ghoul, and lier for Christ Ratzinger. This guy puts the "sick" into sycophant.

Pell has designs on a cushy Vatican position in Ratzinger's brave new world, and so, while all sane people were pulling their heads in and hoping Ratzinger's demonstrated lying about condoms would fade away, up steps Pell to defend the lies with some of his own.
The idea that you can solve a great spiritual and health crisis like AIDS with a few mechanical contraptions like condoms is ridiculous says Pell.
Of course it's ridiculous. The lie here is in pretending that people are advocating the position that condoms can solve the AIDS crisis. No-one, anywhere, is suggesting that condoms alone can solve the crisis. Condoms are an essential part of an integrated approach which includes health and social initiatives.

Pell knows this, but, following Ratsinger's lead, lies to people about it.

Then, to make matters worse, he quotes an unnamed health worker who, Pell claims, told him condoms were not an effective solution to Africa's AIDS problem.
He made the point that the people in remote areas are too poor to afford condoms and the ones that are available are often of very poor quality and weren't used effectively
The health worker is saying that condoms are ineffective in remote areas because they are unavailable, or the ones that are available are of poor quality. Notice the health worker does not say that condoms are ineffective, but it is their unavailability that is making them ineffective.

To any sane, rational person, the solution would be to improve the availability of condoms. But to the fevered and twisted mind of a Ratzinger sycophant, the solution, Pell's Solution, is to remove all condoms.

Lets take Pell's Solution to it's logical conclusion shall we?

Let's see, in Dafur, people are starving through a lack of food, or having sub-standard food. The Pell Solution - remove all food aid!

In Zimbabwe, people are dying through a lack of water, or water contaminated by cholera. The Pell Solution - remove all water!

Pell then deliverers his coup de grace:
If you look at the Philippines you'll see the incidence of AIDS is much lower than it is in Thailand which is awash with condoms
However, the situation is not as simple as Pell would have you think (surprised?)

There appears to be a number of factors at play here, including, a low ratio of customers to sex workers, low rates of certain other sexually transmitted diseases, and limited intravenous drug use.

Indeed as the World Health Organization representative for the Philippines has said.
I think it's a number of different factors adding up. I think they are lucky, but that's not at all the way to control AIDS.
Pell ends with another lie:
There are condoms everywhere and the rate of infection is enormous.

“That's what the Pope is talking about.
Lets, see, what did Ratzinger say again?
[AIDS] was a tragedy that cannot be overcome by money alone, that cannot be overcome through the distribution of condoms, which can even increase the problem.
No Pell, Ratzinger said condoms make AIDS worse. He lied, and you are lying now.

Cardinal Pell - lier, sycophant, Religious Ghoul. Should fit in just nicely with Ratzinger's brave new world.

Sunday, April 12, 2009

Palaeoporn 12

This time Palaeoporn goes monochromatic!

Naraoia (above, scale = 1 cm) has featured here before (what? . . . I know it's not monochromatic, just wait), but this time I’m going to show what a little black and white photography can do (see!).

First of all, this (right) is what Naraoia looked like in the flesh. It had two ‘shields’ an anterior, or head shield, and a posterior shield. These shields overlapped, so that the posterior end of the head shield rested over the anterior edge of the posterior shield.

Underneath the shields, the body looked very much like that of trilobites, to whom they are closely related. In other words they had a many segmented body (including the head), and a pair of biramous appendages on most segments.

Fossils from the Lower Cambrian Emu Bay Shale are not exceptionally well preserved when it comes to fine structure. The fossils have been recrystallised into hulking great fibrous calcite crystals during a subsequent tectonic event. But, they do look good in colour, even the one above which is not a particularly good specimen.

However, occasionally you can get some detailed information, and then the best documentation is obtained using black and white photography, which is why this is still the preferred medium for journals, especially where structure is indistinct and a bugger to document!

All the photography here was done the old fashioned way, before that new-fangled digitally enhancement, with honest to goodness film, and dark rooms, and the inhalation of toxic chemicals during development and printing, Didn't effect me though, but I digress . . . err, who am I again?

Basically light and shade can show up very fine structures that colour cannot. Maybe because we can interpret subtle changes in greyscale as meaningful structures, whereas this is more difficult in colour, I don’t know. But by varying the intensity and the angle of the light, and by using high magnification and very slow film (in this case Ilford 100 and Ilford Pan F Plus) structures can be seen that are either absent of very difficult to see in colour photos.

Below I’ll show a couple of examples of what I mean.

Here is a black and white image of another specimen of Naraoia (click to enlarge). This time you can see some structure. The image on the right has been augmented to show them. Other than that the image has not been manipulated, and the structures are seen because the angle of the light hitting the specimen is very low.

A number of structures in the head can be seen, including the antennae, legs and a remnant of the hypostome, which is a rigid plate that sat directly in front of the mouth. A very thick doublure is also present. This is where the posterior shield has folded back on itself around the margin. This strengthens the shield.

The area where the two shields overlap can also be seen. Now this image is a scan of a negative that has been converted to a JPEG file and then uploaded, so some detail has been lost, but they are there . . . trust me, I’m a doctor!

Still not convinced? OK, how about this:

This image is a magnification of the last (click to magnify further), but with a slight change in the light intensity, and the angle. Other than that, and the augmentation of the right hand image, there has been no manipulation. The field of view is approximately 1 cm by 1.5 cms. Despite the fact that the magnification resulted in a very small depth of field, a number of structures are visible, in fact more so that in the last image.

There are at least 6 head appendages behind the antennae (at a push), and the hypostome is visible. Also, the margins of the anterior and posterior shields are there.

There is also a lot of wrinkling. This is because, in life, the critter was quite domed, and that has been flattened out leaving the mass of wrinkles at the front of the head. Also the left hand margin of the posterior shield is twisted near its anterior margin, and a number of major wrinkles have formed on the posterior shield in response to this twist.

If you can't document your structures, you can't publish them. Which is fine if you are dealing with Burgess Shale levels of preservation. However, the rest of us have to rely of long hours in the photography suite playing with magnification, light intensity, and lighting angles. That's before you get to the developing and printing phase.

Mmmmm . . . developing fluid . . .