Monday, October 20, 2008
Life's Beginnings
In a quick break from SVP, just thought I'd mention an interesting article in Science that appeared on the 16th. Apparently, two fo Stanley Miller's students were going through his lab after his death and found a couple of samples fom his famous experiment on the creation of organic molecules in the primordial soup and decided to retest them. They found double the number of amino acids that Miller found 50 years ago. 22 amino acids were found, including all 20 of the ones used by living organisms today. They did note that the atmosphere back then did not have as much hydrogen as in Miller's experiment, but it did exist at those levels around volcanic outlets, prompting the idea that time and volcanoes may have helped spur the creation of life on Earth.
Sunday, October 19, 2008
Dinos at the SVP meeting
All of the abstracts for the talks and posters I will be mentioning can be found in the Journal of Vertebrate Paleontology, Volume 28, Supplement to Number 3.
I will start with the dinosaurs because 1) they are cool, 2) they are my favorite animal even though they aren't technically in my field of research any more than any other particular animal, and 3) everybody likes dinosaurs, right?
Schmitz gave an interesting talk during the Romer Prize session in which he looks at the orbits of dinosaurs and, after comparing them with modern animals, was able to determine that, even though most dinosaurs were indeed diurnal like commonly thought, many dinosaurs were most likely nocturnal or cathemeral (active all the time). All the pterosaurs he studied were diurnal, but Syntarsus was nocturnal, and Herrerosaurus and the larger (over 296 kg) herbivores were cathemeral.
Evans showed that hadrosaurine crests were unrelated to olfactory ability in that the olfactory region was not involved in the crest. He also showed that the sound estimated from the crest and the optimal hearing frequency based on inner ear casts matched quite nicely. Combine this with the finding that hadrosaurines had enlarged cerebral hemispheres, making them rather intelligent compared to most other dinosaurs, and the conclusion is that they had a complex social structure and their crests played a role in social signalling.
Tsuhiji discussed the first known complete skull of Avimimus, finding that it was a basal oviraptosaur with the horizontal canal of its semicircular canals being more avian than Archaeopteryx.
Hurlburt discussed dino brains, finding that while their forebrain percentages were in the low avian range, their cerebral EQs (cerebrumin proportion to body mass) placed them between reptiles and birds, but closer to reptiles.
Andy Farke did a decent job ruling out the shock absorber hypothesis for the frontal sinuses in ceratopsians and modern bovids, but couldn't say what if any function they might have had.
Longrich found that having feathers on the legs allowed Archaeopteryx to increase lift and reduces turning radius and drag thereby improving performance at low gliding speeds. He also found the original Berlin specimen had feathers preserved on its legs until overzealous preparators removed them. Interestingly he says this supports the arboreal origin of flight.
This puts him in direct opposition to Dececchi and Larsson, who looked at the anatomy of derived maniraptorans to see how well they compared to known claw or grip climbers and found their anatomy was all wrong to be arboreal, saying that, while they may have gotten into trees from time to time, they certainly weren't arboreal and were scansorial at best.
Zanno reprted a new phylogeny of therizinosaurs based on two new specimens, which broke up the presumed monophyly of therizinosaurs and oviraptors, putting therizinosaurs as basal maniraptora and ecologically convergent with oviraptors. Interestingly, this makes herbivory rather common in maniraptora, so they evolved from hypercarnivores into herbivores and omnivores with the derived manirpatora that were hypercarnivores secondarily derived it.
Barrett reviewed the hypothesis that dinosaurs coevolved with cycads and found no evidence that they either ate them or would have had problems even if they had and no association with large dinosaurs, so absolutely no evidence that dinosaurs in particular had anything to do with cycad evolution.
Carrano did another study of dino diversity in the late Maastricthian and found no evidence that dinos were on the decline in the Western US, but can't say globally as the data just isn't there.
Hayashi found that stegoasaur spikes had thick compact bone but ankylosaurs spikes and clubs had thin bone on their periphery so they clearly were doing something different with them.
Ok, it's getting late and there is much more to say, but for now, I will report on one last crazy thing. Witmer described the first detailed description of ankylosaur nasal passages and the best way to describe them is the crazy straw nose. I can honestly say I have never seen anything quite like it. The nasal passages, rather than having a series of paranasal sinuses, had a crazy twisted tortuous path through the head. Very odd.
I will start with the dinosaurs because 1) they are cool, 2) they are my favorite animal even though they aren't technically in my field of research any more than any other particular animal, and 3) everybody likes dinosaurs, right?
Schmitz gave an interesting talk during the Romer Prize session in which he looks at the orbits of dinosaurs and, after comparing them with modern animals, was able to determine that, even though most dinosaurs were indeed diurnal like commonly thought, many dinosaurs were most likely nocturnal or cathemeral (active all the time). All the pterosaurs he studied were diurnal, but Syntarsus was nocturnal, and Herrerosaurus and the larger (over 296 kg) herbivores were cathemeral.
Evans showed that hadrosaurine crests were unrelated to olfactory ability in that the olfactory region was not involved in the crest. He also showed that the sound estimated from the crest and the optimal hearing frequency based on inner ear casts matched quite nicely. Combine this with the finding that hadrosaurines had enlarged cerebral hemispheres, making them rather intelligent compared to most other dinosaurs, and the conclusion is that they had a complex social structure and their crests played a role in social signalling.
Tsuhiji discussed the first known complete skull of Avimimus, finding that it was a basal oviraptosaur with the horizontal canal of its semicircular canals being more avian than Archaeopteryx.
Hurlburt discussed dino brains, finding that while their forebrain percentages were in the low avian range, their cerebral EQs (cerebrumin proportion to body mass) placed them between reptiles and birds, but closer to reptiles.
Andy Farke did a decent job ruling out the shock absorber hypothesis for the frontal sinuses in ceratopsians and modern bovids, but couldn't say what if any function they might have had.
Longrich found that having feathers on the legs allowed Archaeopteryx to increase lift and reduces turning radius and drag thereby improving performance at low gliding speeds. He also found the original Berlin specimen had feathers preserved on its legs until overzealous preparators removed them. Interestingly he says this supports the arboreal origin of flight.
This puts him in direct opposition to Dececchi and Larsson, who looked at the anatomy of derived maniraptorans to see how well they compared to known claw or grip climbers and found their anatomy was all wrong to be arboreal, saying that, while they may have gotten into trees from time to time, they certainly weren't arboreal and were scansorial at best.
Zanno reprted a new phylogeny of therizinosaurs based on two new specimens, which broke up the presumed monophyly of therizinosaurs and oviraptors, putting therizinosaurs as basal maniraptora and ecologically convergent with oviraptors. Interestingly, this makes herbivory rather common in maniraptora, so they evolved from hypercarnivores into herbivores and omnivores with the derived manirpatora that were hypercarnivores secondarily derived it.
Barrett reviewed the hypothesis that dinosaurs coevolved with cycads and found no evidence that they either ate them or would have had problems even if they had and no association with large dinosaurs, so absolutely no evidence that dinosaurs in particular had anything to do with cycad evolution.
Carrano did another study of dino diversity in the late Maastricthian and found no evidence that dinos were on the decline in the Western US, but can't say globally as the data just isn't there.
Hayashi found that stegoasaur spikes had thick compact bone but ankylosaurs spikes and clubs had thin bone on their periphery so they clearly were doing something different with them.
Ok, it's getting late and there is much more to say, but for now, I will report on one last crazy thing. Witmer described the first detailed description of ankylosaur nasal passages and the best way to describe them is the crazy straw nose. I can honestly say I have never seen anything quite like it. The nasal passages, rather than having a series of paranasal sinuses, had a crazy twisted tortuous path through the head. Very odd.
News from the SVP meeting
Just got back from the annual meeting of the Society of Vertebrate Paleontology in Cleveland, where I reported on my work, but since I already know about mine, I won't report on it here other than to say it is devilishly difficult to reconstruct soft tissue from sediment traces, but there are things you can lean before prepping out a fossil. While I was gone, I missed the announcement of the first known vertebrate neck in tiktaalik, as reported in Nature (Downs, Jason P. et al. 2008. The cranial endoskeleton of Tiktaalik roseae. Nature vol. 455 (October 16), 925 -929). This is rather important as it provided a great advantage to the animal allowing it to turn its head without completely realigning its whole body. Downs gave a talk about this at the meeting, explaining that the head had several features making it more tetrapod-like, including the lack of an operculum and reduced hyomandibular bone that helped free up the neck and a more complex joints between skull bones reducing their mobility.
In the next several posts, I will relate several of the items I found interesting at the meeting, some of which you may hear about in other arenas, some you most likely won't.
In the next several posts, I will relate several of the items I found interesting at the meeting, some of which you may hear about in other arenas, some you most likely won't.
Friday, October 10, 2008
Civic Science Literacy in the United States
Yesterday I got the latest issue of Science News, in which the editorial discussed science in politics. Coincidentally, I also went to a talk by Jon Miller, from Michigan State University titled, “Scientific Literacy and Citizenship in the 21st Century.” His main thesis was that many of our most pressing social and political issues are at their core scientific and that this will only increase as time passes. Unfortunately, most people do not have even a basic understanding of science and as such, can not even understand enough of the issue to intelligently discuss them let alone make policy decisions about them.
Many people have the idea that knowing the science is not required because common sense will allow figuring out enough to adequately make decisions. While that was true a hundred years ago, that is far from reality today. The issues are simply too broad scale and complex for standard common sense to work. Quite simply, if you can’t even understand the arguments, you can’t decide what to believe using rational thought.
His talk had good news and bad news. The good news is that the United States was second only to Sweden in the number of its citizenry that could pass a basic science test. The bad news is that we only rate 25% (for comparison, Sweden was just over 35% and the EU averaged only 15%. We have also improved in the last twenty years as we only rated 10% in 1988. However, with the issues facing us now, having only 1 in 4 of the population able to even begin to understand them is a serious danger to democracy.
So what brought our score down below Sweden? The rank of the US in understanding evolution is 33 out of 34 countries with only 40% accepting evolution, ahead of only Turkey. Iceland was number one with over 80% of their populace conversant in basic evolutionary concepts. The factor most strongly correlated with the rejection of evolution was religious fundamentalism, which actually strongly negatively correlated with science literacy of any kind.
The causes for these scores were seen to lie in two factors: our high schools and our universities. Our high schools rate virtually last in the world. He hypothesized that this was due to the fact that we are the only country to fund our schools using property taxes, which woefully underfunds our public schools. However, this is counterbalanced by our universities, which rate among the best. We are also the only country that requires virtually all college students to take a year of a core set of general education courses which include introductory science courses in addition to the three years required for their major. Apparently, in other countries, students only take the courses relating to their major. Thus, those not in the sciences never need take a science class. Unfortunately, only 28% have a college degree, which is behind many other countries.
He and his colleagues correlated several factors that affected science literacy. Despite what many people seem to think, gender was not a factor and he rightfully disparages the prevalent attitude that girls can’t do math and science. In fact, considering that women now outnumber men in colleges by over 6% and are increasing their dominance in colleges, young women are more likely than men to be scientifically literate.
The single biggest factor (with a correlation of .78) was having had the basic science courses in college. Because of this large effect, he advocated gearing these courses to increasing their effectiveness in enhancing adult continuing education. Other often discussed effects were also evaluated, including internet use with a positive correlation of .39. Religious fundamentalism had the worst affect, with a negative correlation of .2. Interestingly, TV had no effect either positive or negative.
As a case study, he specifically studied attitudes toward climate change. They were only able to account for 30% of the variance, but of that 30%, the overriding factor was political party. Republicans were likely to dismiss it, Democrats were more likely to think it was a serious concern. Of those that were concerned, they were able to account for most of the variance about who tried to do something about it, such as contacting their congressmen to talk about political issues. Being scientifically literate had a correlation of .41, but a bigger influence was seen by having children, with a correlation of .55. Climate change is an inherently long term issue. Apparently, having children causes people to give more consideration to things that affect their kids. Again, religious fundamentalism negatively correlated with concern about climate change. Of course, the majority of religious fundamentalists were Republican.
I’ll just finish this summary of his talk with two thoughts of his. “Civic scientific literacy provides a set of conceptual and practical tools…to make full use of the Internet and related information centers.” One good thing that Bush has done for the country is that “Political scientists no longer argue that is makes no difference who wins the elections.”
Many people have the idea that knowing the science is not required because common sense will allow figuring out enough to adequately make decisions. While that was true a hundred years ago, that is far from reality today. The issues are simply too broad scale and complex for standard common sense to work. Quite simply, if you can’t even understand the arguments, you can’t decide what to believe using rational thought.
His talk had good news and bad news. The good news is that the United States was second only to Sweden in the number of its citizenry that could pass a basic science test. The bad news is that we only rate 25% (for comparison, Sweden was just over 35% and the EU averaged only 15%. We have also improved in the last twenty years as we only rated 10% in 1988. However, with the issues facing us now, having only 1 in 4 of the population able to even begin to understand them is a serious danger to democracy.
So what brought our score down below Sweden? The rank of the US in understanding evolution is 33 out of 34 countries with only 40% accepting evolution, ahead of only Turkey. Iceland was number one with over 80% of their populace conversant in basic evolutionary concepts. The factor most strongly correlated with the rejection of evolution was religious fundamentalism, which actually strongly negatively correlated with science literacy of any kind.
The causes for these scores were seen to lie in two factors: our high schools and our universities. Our high schools rate virtually last in the world. He hypothesized that this was due to the fact that we are the only country to fund our schools using property taxes, which woefully underfunds our public schools. However, this is counterbalanced by our universities, which rate among the best. We are also the only country that requires virtually all college students to take a year of a core set of general education courses which include introductory science courses in addition to the three years required for their major. Apparently, in other countries, students only take the courses relating to their major. Thus, those not in the sciences never need take a science class. Unfortunately, only 28% have a college degree, which is behind many other countries.
He and his colleagues correlated several factors that affected science literacy. Despite what many people seem to think, gender was not a factor and he rightfully disparages the prevalent attitude that girls can’t do math and science. In fact, considering that women now outnumber men in colleges by over 6% and are increasing their dominance in colleges, young women are more likely than men to be scientifically literate.
The single biggest factor (with a correlation of .78) was having had the basic science courses in college. Because of this large effect, he advocated gearing these courses to increasing their effectiveness in enhancing adult continuing education. Other often discussed effects were also evaluated, including internet use with a positive correlation of .39. Religious fundamentalism had the worst affect, with a negative correlation of .2. Interestingly, TV had no effect either positive or negative.
As a case study, he specifically studied attitudes toward climate change. They were only able to account for 30% of the variance, but of that 30%, the overriding factor was political party. Republicans were likely to dismiss it, Democrats were more likely to think it was a serious concern. Of those that were concerned, they were able to account for most of the variance about who tried to do something about it, such as contacting their congressmen to talk about political issues. Being scientifically literate had a correlation of .41, but a bigger influence was seen by having children, with a correlation of .55. Climate change is an inherently long term issue. Apparently, having children causes people to give more consideration to things that affect their kids. Again, religious fundamentalism negatively correlated with concern about climate change. Of course, the majority of religious fundamentalists were Republican.
I’ll just finish this summary of his talk with two thoughts of his. “Civic scientific literacy provides a set of conceptual and practical tools…to make full use of the Internet and related information centers.” One good thing that Bush has done for the country is that “Political scientists no longer argue that is makes no difference who wins the elections.”
Monday, October 6, 2008
Dinosaur/Bird connection even stronger
Vargas AO, Kohlsdorf T, Fallon JF, VandenBrooks J, Wagner GP (2008) The Evolution of HoxD-11 Expression in the Bird Wing: Insights from Alligator mississippiensis. PLoS ONE 3(10): e3325. doi:10.1371/journal.pone.0003325.
This paper, published Oct.3rd, puts another nail in the coffin of the arguments against the dinosaurian origins of birds. One of the biggest arguments used to "disprove" the dino/bird relationship was that, using embryological evidence, birds have digits 2, 3, and 4 on their hands and lost digits 1 and5, but dinosaurs have digits 1, 2, and 3 and lost digits 4 and 5. Morphologically, bird fingers look like digits 1, 2, and 3, just like dinosaur digits. Vargas and crew looked at the activity of the HoxD-11 in crocodiles, birds and mammals. Mammals express HoxD-11 in digits 2-5, but not in 1, crocs express HoxD-11 in digits 2-5, but not in 1. Guess what? Birds express HoxD-11 in digits 2 and 3, but not in digit 1. So birds do not in fact have digits 2, 3, and 4 like the people who disagree with the dino-bird theory. So their biggest argument has now been quite convincingly obliterated. Think we can end this debate now?
This paper, published Oct.3rd, puts another nail in the coffin of the arguments against the dinosaurian origins of birds. One of the biggest arguments used to "disprove" the dino/bird relationship was that, using embryological evidence, birds have digits 2, 3, and 4 on their hands and lost digits 1 and5, but dinosaurs have digits 1, 2, and 3 and lost digits 4 and 5. Morphologically, bird fingers look like digits 1, 2, and 3, just like dinosaur digits. Vargas and crew looked at the activity of the HoxD-11 in crocodiles, birds and mammals. Mammals express HoxD-11 in digits 2-5, but not in 1, crocs express HoxD-11 in digits 2-5, but not in 1. Guess what? Birds express HoxD-11 in digits 2 and 3, but not in digit 1. So birds do not in fact have digits 2, 3, and 4 like the people who disagree with the dino-bird theory. So their biggest argument has now been quite convincingly obliterated. Think we can end this debate now?
Acid makes the oceans louder
In a study in the most recent Geophysical Research Letters, Keith Hestor and crew calculated that the predicted drop in oceanc pH of 0.3 points over the next 40 years will cause a 70% increase in the distance sound will travel in the oceans. It's not really understood why this happens but it is known that acidity increases the sound conductance of seawater. What was surprising was how much the rather modest decrease in pH would affect the conductance.
Life in the Cretaceous polar seas
Karen Chin and several coauthors published an interesting (to me at least) paper in the Proc. R. Soc. B online journal August 19 called "Life in a temperate Polar sea: a unique taphonomic window on the structure of a Late Cretaceous Arctic marine ecosystem " (DOI
10.1098/rspb.2008.0801). Through study of the sediments and fossils within the late Cretaceous rocks on Devon Island, Canada, they were able to deduce that a thriving ecosystem lived in temperate waters in the polar seas. Whereas the modern ecosystem is supported by nutrient upwelling, the paleo ecosystem appears to have been supported by terrestrial forests that contributed abundant nutrients to the marine waters. So, while it may not have been exactly warm, at least there wasn't constant ice. Whatever lived there still had to deal with long cold nights though, but at least there was plenty of food.
10.1098/rspb.2008.0801). Through study of the sediments and fossils within the late Cretaceous rocks on Devon Island, Canada, they were able to deduce that a thriving ecosystem lived in temperate waters in the polar seas. Whereas the modern ecosystem is supported by nutrient upwelling, the paleo ecosystem appears to have been supported by terrestrial forests that contributed abundant nutrients to the marine waters. So, while it may not have been exactly warm, at least there wasn't constant ice. Whatever lived there still had to deal with long cold nights though, but at least there was plenty of food.
Sunday, October 5, 2008
World's Oldest Footprints
Man I wish I could have gone to the Geological Society of America meeting going on right now. A huge meeting with lots of great stuff, such as this talk reported by LiveScience.com given today reporting on the oldest known footprints. Soo-Yeun Ahn, a graduate student at Ohio State University presented a poster about a 570 million year old track site discovered in Nevada by his advisor, Dr. Loren Babcock in 2000. the track is apparently a centipede-like creature. Oh well, I am sure that the Society of Vertebrate aleontology will have tons of cool stuff (actually, I know it will, but I am not allowed to say anything about it until it is presented at the meeting because of the news embargo to allow the presenters to be the first to present their cool stuff to the world).
Wednesday, October 1, 2008
Dinosaur had avian air sacs redux
Sereno has come out with a new paper (Sereno PC, Martinez RN, Wilson JA, Varricchio DJ, Alcober OA, et al. (2008) Evidence for Avian Intrathoracic Air Sacs in a New Predatory Dinosaur from Argentina. PLoS ONE 3(9): e3303). In this paper he introduces a new dinosaur by the name of Aerosteon riocoloradensis, which falls out as a basal tetanuran, down with the allosauroids. But the main part of the paper lays out Sereno's view of the evolution of avian air sacs within the dinosaurs. Seeing as Pat O'Connor has published on this topic previously and his office is right down the hall from mine, I was a bit miffed at how dismissively Sereno treated Pat's work. While I have some issues with the paper, not least of which is that he seems to be saying basically the same thing as Pat while dissing him at the same time, I do think he does bring some additional points to the table and advances the discussion. It remains to be seen whether or not his claims hold up, but that's ok, it spurs debate and research, which is a good thing. The paper is worth a read.
Sympatric speciation through sensory isolation
Many people have claimed that new species have to be created by geographic isolation, that is, they do not believe that sympatric speciation (new species arising from a population in the same area) can happen. I personally think that is hogwash and it can certainly happen. A nice case in point is an article in the October 2 Nature by Seerhausen et al. called "Speciation through sensory drive in cichlid fish." Cichlids are amazingly diverse and many species occur alongside other species of cichlids. Seerhausen et al. studied several species that occur sympatrically when considering just two-dimensional geography, but occur at different depths. The species are different colors and their visual sensitivity matches the change in light absorption at the corresponding depth, meaning their eyes are optimized for lack of a better word for the depth at which they live and their coloration shows corresponding adaptation. it is fairly clear that these species all originated from the same ancestor that lived at all depths but then speciated by adapting to specific depths. The case could be argued that this depth separation counts as allopatric, or geographic separation, but I think that would be stretching the definition a bit thin as nothing prevents the fish from swimming throughout all depths other than their preferences.
International Dinosaur Month
Ah, the wonderful days leading up to meetings, when one realizes they have monthsof work to do in a few short weeks. Ok, so I've been bad and there has been lots of cool stuff that has come out, including a new group of whales to go along with a new fossil whale as published in the latest journal of Vertebrate Paleontology, but for right now let me just say that today is the start of International Dinosaur Month. Go hug your local paleontologist and enjoy your local dinosaurian fauna, either by doing some birdwatching or by eating some fried chicken I hope I don't have to tell you that birds evolved from dinosaurs and are thus technically dinosaurs themselves, right?).
Monday, September 22, 2008
12 year old leaps solar tech forward
Wow. Ok, this is not exactly breaking news, as it was first reported via Treehugger.com on the 18th, but it is amazing. A 12 year old kid developed a 3D solar cell that collects 500 times the energy as commercially available solar cells and 9 times the best 3d solar cells that have been developed (and not available outside prototypes in labs). It does this by not only collecting visible light, but UV as well and by using carbon nanotubes in a 3D array to better absorb more light and reduce the inevitable dissipation of energy during the conversion and distribution of the energy. Now if only he can get it developed for commercial use.
Thursday, September 18, 2008
Getting Hotter
Here's a shocker: global warming is going to increase, according to the perspective in Science by Peter Cox and Chris Jones ("CLIMATE CHANGE:Illuminating the Modern Dance of Climate and CO2," Science 19 September 2008:Vol. 321. no. 5896, pp. 1642 - 1644DOI: 10.1126/science.1158907). According to their data, in which they incorporate paleoclimatic data from the Little Ice Age from 1500-1750, the models that best reproduce the link between climate and carbon dioxide levels shown during the LIA and 20th century correlations are the most severe, i.e. the ones predicting the largest increases. So we can expect that temperatures will be increasing faster as time goes on. This means that if you live within 20 feet of sea level or are planning on buying land that close to sea level, you might want to reconsider your living arrangements or plan on spending a lot on water sealants.
Leonardo the hadrosaur
Congratulations to my old lab mate Justin Tweet and advisor Dr. Karen Chin on their article "Probable Gut Contents Within A Specimen Of Brachylophosaurus Canadensis (Dinosauria: Hadrosauridae) From the Upper Cretaceous Judith River Formation Of Montana" published in the latest Palaios (September 2008; v. 23; no. 9; p. 624-635; DOI: 10.2110/palo.2007.p07-044r). It is a nice article demonstrating the last dinner of the hadrosaur nicknamed "Leonardo". Glad to see that Justin got his thesis published.
Superstruct: Play for the Future
Ok, I know, I'm behind. Hopefully, I'll catch up:) But I ran across a game that everyone should play. It is a six-week experiment beginning September 22 called Superstruct, billed as the first massively multiplayer forecasting game. The game is based around major disasters that strike in 2019. While the game goal is to figure out how to survive and keep some form of civilization going, the idea behind the game is to use everyone's intellect in a massive simulation to inspire ideas on potential problems facing our planet so we can better prepare ourselves for handling crises. There is even a subset of the game that is specialized for museum workers. I think it's a great idea and I encourage everyone to play. The more people that play, the more information we get on how to survive major threats to our world.
The game is being run by The Institute for the Future (IFTF) and the Center for the Future of Museums (an initiative of the American Association of Museums). To play or just to find out more about it, go to
http://www.iftf.org/node/2098. Do it! Do it now!
The game is being run by The Institute for the Future (IFTF) and the Center for the Future of Museums (an initiative of the American Association of Museums). To play or just to find out more about it, go to
http://www.iftf.org/node/2098. Do it! Do it now!
Sunday, September 14, 2008
The Taphonomy of Oil
Jere Lipps wrote a wonderful article in the latest Palaontologica Electronica on how oil is formed, the processes of developing our oil resources, and why it can't last forever. While I may quibble with his decay under oxic vs. anoxic conditions, the article is a great explanation of the oil problem in terms everyone can understand and should be required reading for everyone, and to help that, here is the link to the article: http://palaeo-electronica.org/2008_2/commentary/oil.htm.
Hadrosaur 3D chewing computer animation
An article in the latest Palaeontologica Electronica (http://palaeo-electronica.org/2008_2/132/index.html) shows a 3D computer model of an Edmontosaurus skull showing how the skull moves during chewing. One of my labmates, Casey Holiday, is a co-author on this paper. This I find rather interesting, because Casey does not believe what the paper says. The paper does a great job of illustrating how all the synovial joints move during chewing ala the classic pleurokinetic hadrosaur skull. The problem is that in Casey's dissertation, one of the things he showed was that just because one has a synovial joint doesn't mean it moves. Lizards all have wonderfully fragmented skulls with synovial joints all over the place, but are not generally thought to be pleurokinetic, for instance. As Casey demonstrated in his dis, to have a pleurokinetic skull that moves like they show requires a chain of movments that all have to occur. If any one of them are locked into position, the whole thing is stuck, sort of like throwing a wrench into a gear. This happens to be the case with hadrosaurs. What Casey really thinks is going on is that these synovial joints allow the skull to grow quickly, keeping it mobile enough to allow growth, but not so mobile as to move during chewing. Actually, I should say here that this is an overly-simplistic representation of his views and that it is a bit more complex than that, including a certain amount of evolutionary baggage, but you get the point, that being the skulls were actually most likely rather akinetic, i.e. they didn't change their shape every time they bit down on something. So why does his name appear in this paper? He worked out the chewing mechanisms for the group, but the others put together the computer modelling and they went with the classic view rather than what Casey had worked out. My opinion is that Casey is right and will be vindicated later on.
Friday, September 12, 2008
Early dinosaur evolution
In today's issue of Science, Stephen Brusatte et al. published an interesting article called "Superiority, Competition, and Opportunism in the Evolutionary Radiation of Dinosaurs," in which they state that the early dinosaurs did not out compete the early crurotarsans, which were the crocodile ancestors that were dominating the scenery then. All well and good and they add a new analysis to the mix. I'm all for that and like the publication of the article.
However, unlike what they claim and what Science News claims (http://www.sciencenews.org/), this is not exactly a new claim. As the Science News article mentions Irmis et al. said essentially the same thing last year in the same journal. Brusatte et al. claim their study is superior because they view it as a "two-step" process, i.e. the rise of the herbivorous sauropodomorphs followed by the theropods and others, whereas the other studies viewed it as a single event. Fine, while I might disagree that the timing data we have for that time period is sufficient to make such a claim, I won't argue about that. What I do argue with is their suggestion that the competition model is the currently accepted hypothesis for the rise of the dinosaurs, which is not true at all. It has been pretty apparent to anyone who has kept up with the literature that few people accept that view anymore and the dinosaurs have been seen more commonly as oppurtunistic, that filled the void created by the decline of the terrestrial crurotarsans.
Moreover, Irmis et al. were not exactly the first to say this, they more than anything else put the nail in the coffin of the competition hypothesis by supplying good data. People had been saying this for decades. William Sill in particular published the oppurtunistic model for early dinosaurian radiation back in the sixties and early seventies. While I can forgive Brusatte for not knowing about Sill's papers, I can not believe that Benton, one of the co-authors, didn't know about them. So I find it curious that Sill was not even cited in their paper.
So all in all, if I had been reviewing it, I would first off had said this paper is not Science journal material and would have recommended sending it to another journal for publication with a few alterations. I am very curious how this got into Science, considering the high level of competition for publication there.
However, unlike what they claim and what Science News claims (http://www.sciencenews.org/), this is not exactly a new claim. As the Science News article mentions Irmis et al. said essentially the same thing last year in the same journal. Brusatte et al. claim their study is superior because they view it as a "two-step" process, i.e. the rise of the herbivorous sauropodomorphs followed by the theropods and others, whereas the other studies viewed it as a single event. Fine, while I might disagree that the timing data we have for that time period is sufficient to make such a claim, I won't argue about that. What I do argue with is their suggestion that the competition model is the currently accepted hypothesis for the rise of the dinosaurs, which is not true at all. It has been pretty apparent to anyone who has kept up with the literature that few people accept that view anymore and the dinosaurs have been seen more commonly as oppurtunistic, that filled the void created by the decline of the terrestrial crurotarsans.
Moreover, Irmis et al. were not exactly the first to say this, they more than anything else put the nail in the coffin of the competition hypothesis by supplying good data. People had been saying this for decades. William Sill in particular published the oppurtunistic model for early dinosaurian radiation back in the sixties and early seventies. While I can forgive Brusatte for not knowing about Sill's papers, I can not believe that Benton, one of the co-authors, didn't know about them. So I find it curious that Sill was not even cited in their paper.
So all in all, if I had been reviewing it, I would first off had said this paper is not Science journal material and would have recommended sending it to another journal for publication with a few alterations. I am very curious how this got into Science, considering the high level of competition for publication there.
Thursday, September 11, 2008
Facebook evolves
I am not exactly the first person to support social networking sites, i generally try to avoid them. But Facebook has recently come out with a new game called "Evarium". It is an evolution based game in which you control the destinies of spirograph critters. You set the mutation rates, breeding rates, and a number of other parameters, along with the look of the beginning critters and then watch them go. You see them grow, reproduce, grow old and die. Clicking on any individual provides information such as, sex, what it's doing at the moment, and what sort of partner it is looking for. It's like a little dating profile for your imaginary creatures. You can also introduce traumatic events, such as introducing new types or killing off all of a certain type. Watching what happens to the look and distributions of the creatures is pretty cool and is an innovative way of teaching about evolutionary concepts. The ads that go along with the game are for evolution-based books, so even the ads are cool. This is pretty much the only online game like this that I whole-heartedly recommend checking out. If anyone knows of other games like this, drop me a line.
Wednesday, September 10, 2008
Molecular clocks take another hit
Here's an interesting article in Revista di Biologia / Biology Forum. I have always had doubts about the molecular clock hypothesis, which is the idea that we can estimate divergence rates between organisms based on rates of change in their DNA. Admittedly, some the DNA and protein sequences Huang uses in his paper are hotly debated as to their validity, but the paper is intriguing nonetheless.
Huang, S. “Ancient Fossil Specimens of Extinct Species Are Genetically More Distant to an Outgroup than Extant Sister Species Are.” Biology Forum / Rivista di Biologia, v. 101, 2008, p. 93-108.
Abstract. There exists a remarkable correlation between genetic distance as
measured by protein or DNA dissimilarity and time of species divergence as
inferred from fossil records. This observation has provoked the molecular
clock hypothesis. However, data inconsistent with the hypothesis have steadily
accumulated in recent years from studies of extant organisms. Here the published
DNA and protein sequences from ancient fossil specimens were examined
to see if they would support the molecular clock hypothesis. The hypothesis
predicts that ancient specimens cannot be genetically more distant to an
outgroup than extant sister species are. Also, two distinct ancient specimens
cannot be genetically more distant than their extant sister species are. The
findings here do not conform to these predictions. Neanderthals are more
distant to chimpanzees and gorillas than modern humans are. Dinosaurs are
more distant to frogs than extant birds are. Mastodons are more distant to
opossums than other placental mammals are. The genetic distance between
dinosaurs and mastodons is greater than that between extant birds and
mammals. Therefore, while the molecular clock hypothesis is consistent with
some data from extant organisms, it has yet to find support from ancient
fossils. Far more damaging to the hypothesis than data from extant organisms,
which merely question the constancy of mutation rate, the study of
ancient fossil organisms here challenges for the first time the fundamental
premise of modern evolution theory that genetic distances had always increased
with time in the past history of life on Earth.
Huang, S. “Ancient Fossil Specimens of Extinct Species Are Genetically More Distant to an Outgroup than Extant Sister Species Are.” Biology Forum / Rivista di Biologia, v. 101, 2008, p. 93-108.
Abstract. There exists a remarkable correlation between genetic distance as
measured by protein or DNA dissimilarity and time of species divergence as
inferred from fossil records. This observation has provoked the molecular
clock hypothesis. However, data inconsistent with the hypothesis have steadily
accumulated in recent years from studies of extant organisms. Here the published
DNA and protein sequences from ancient fossil specimens were examined
to see if they would support the molecular clock hypothesis. The hypothesis
predicts that ancient specimens cannot be genetically more distant to an
outgroup than extant sister species are. Also, two distinct ancient specimens
cannot be genetically more distant than their extant sister species are. The
findings here do not conform to these predictions. Neanderthals are more
distant to chimpanzees and gorillas than modern humans are. Dinosaurs are
more distant to frogs than extant birds are. Mastodons are more distant to
opossums than other placental mammals are. The genetic distance between
dinosaurs and mastodons is greater than that between extant birds and
mammals. Therefore, while the molecular clock hypothesis is consistent with
some data from extant organisms, it has yet to find support from ancient
fossils. Far more damaging to the hypothesis than data from extant organisms,
which merely question the constancy of mutation rate, the study of
ancient fossil organisms here challenges for the first time the fundamental
premise of modern evolution theory that genetic distances had always increased
with time in the past history of life on Earth.
Tardigrades: Toughest Animal Ever
Space.com reported today fascinating new work on tardigrades in space. Tardigrades, aka water bears, are microscopic invertebrates that can survive almost anything, desiccation, heat, cold, you name it. Now they have reached new heights, literally. The European Space Agency shot them into space last year and recently retrieved them. They not only survived vacuum, extreme cold, cosmic radiation and UV radiation from the sun 1000 times what reaches the surface, but were able to reproduce just fine afterwards. They are the gold medalists of eukaryote (multicellular) survivalists. They rank right up there with my favorite unicellular organism, Deinococcus radiodurans (although I think they are now called Micrococcus), which can withstand enough radiation to melt Pyrex glass. Their DNA can be shredded and they just put it back together and keep on ticking. Timex must be supremely jealous. What keeps these bacteria in check, you may ask? Because they grow incredibly slowly and are thus outcompeted for resources by pretty much everything else, so they only live in the fringes where nothing else can. Still, they are awesomely cool.
Tuesday, September 9, 2008
Blogs and Academia
There was recently an international science bloggers convention in London (yes, everything has its own convention these days, I am sure there will be a convention for CEOs who wear pink bunny slippers to work any day now). Pretty much all the attendants agreed that science communication from academics to the public is in general pretty abyssmal. But one thing in particular struck me as interesting and which made me change this blog a bit. It was pointed out that many academics run their blogs anonymously because many senior academics (aka department chairs and the like) view blogging as a waste of time and letting it be known to one's superiors that one blogs can negatively impact your career if you are a young academic. While I see definite value in this (otherwise I wouldn't be doing it, see the greetings post), I would one day like to have a real job. Therefore, I have made this blog anonymous until I can sort out what this means to my own career. If you have any comments, suggestions, or other views on the matter, please comment as I would like to know other people's opinions on the matter.
Sunday, September 7, 2008
Bizarre hyoids
Just got a look at howler monkey hyoids and they are truly strange. For those that don't know, hyoids are the little floater bones in the front of the throat that serve as attachment points for some tongue and throat muscles. Most are shaped like little Us or Ys with two sets of "horns". The howler monkey's hyoid is a pouch, which apparently they use as a resonator to help them scream really loud. Ranks right up there in strangeness with flickers and hummingbirds that can have their hyoids wrap around their heads to let them stick their tongues WAY out.
Glad I'm short
Luisa Zuccolo et al. in the September issue of Cancer Epidemiology, Biomarkers and Prevention report that taller men are at greater risk of prostate cancer. Prostate cancer risk increased on average almost 1.5%/inch of height over the shortest person in the study. Course, the statistical support was "weak" and not as influential as other factors such as age, ethnicity, and family history, but I'll take what I can get.
Saturday, September 6, 2008
Lack of evidence is not evidence of absence, NOT!
I'll start this blog off with a bit of scientific philosophy.
“Lack of evidence is not evidence of absence.” This is one of the most commonly stated axioms in science that is obviously a fallacy yet taken as gospel in many circles. Virtually all scientists work under the assumption of its very antithesis. Bigfoot, the Loch Ness Monster, UFOs, and many other things relegated to “fringe science” and fantasy are dismissed precisely because there is a lack of sufficient evidence for most scientists to deem them credible. Scientists in typical practice do not accept hypotheses without having some evidence to lend them credence. Therefore, it follows that a lack of evidence does indeed constitute sufficient evidence of absence for most scientists to withhold support for a hypothesis. Secondly, if absence of evidence does not constitute evidence of absence, what then would qualify? If one looks for evidence to support a hypothesis and finds none, it is usually taken to mean the hypothesis is not true, until such a time that evidence turns up.
Therein lies the essential qualifier for the axiom that is commonly forgotten. Many people remember Sagan stating “lack of evidence is not evidence of absence.” Yet what is commonly neglected is the context in which the statement was made. His statement referred to the fact that until someone looked for evidence, one could not say a priori that it did not exist. However, once that task was completed, lack of evidence does indeed mean evidence of absence. Thus, more correctly, we should be saying that IF no one has looked, lack of evidence is not evidence of absence. However, IF after a thorough search and still no evidence appears, THEN we can conclude absence of evidence is indeed evidence of absence. This does not mean that at some later date evidence will not be found. It simply means that as of this point, no evidence exists to support the claim, so it is considered unfounded. It is then incumbent on those who continue to believe the hypothesis to find evidence that will convince their peers. But to simply regurgitate “lack of evidence is not evidence of absence” is intellectually disingenuous and scientifically without merit; in short, a cheat to avoid accepting the logical alternative until evidence can be found.
“Lack of evidence is not evidence of absence.” This is one of the most commonly stated axioms in science that is obviously a fallacy yet taken as gospel in many circles. Virtually all scientists work under the assumption of its very antithesis. Bigfoot, the Loch Ness Monster, UFOs, and many other things relegated to “fringe science” and fantasy are dismissed precisely because there is a lack of sufficient evidence for most scientists to deem them credible. Scientists in typical practice do not accept hypotheses without having some evidence to lend them credence. Therefore, it follows that a lack of evidence does indeed constitute sufficient evidence of absence for most scientists to withhold support for a hypothesis. Secondly, if absence of evidence does not constitute evidence of absence, what then would qualify? If one looks for evidence to support a hypothesis and finds none, it is usually taken to mean the hypothesis is not true, until such a time that evidence turns up.
Therein lies the essential qualifier for the axiom that is commonly forgotten. Many people remember Sagan stating “lack of evidence is not evidence of absence.” Yet what is commonly neglected is the context in which the statement was made. His statement referred to the fact that until someone looked for evidence, one could not say a priori that it did not exist. However, once that task was completed, lack of evidence does indeed mean evidence of absence. Thus, more correctly, we should be saying that IF no one has looked, lack of evidence is not evidence of absence. However, IF after a thorough search and still no evidence appears, THEN we can conclude absence of evidence is indeed evidence of absence. This does not mean that at some later date evidence will not be found. It simply means that as of this point, no evidence exists to support the claim, so it is considered unfounded. It is then incumbent on those who continue to believe the hypothesis to find evidence that will convince their peers. But to simply regurgitate “lack of evidence is not evidence of absence” is intellectually disingenuous and scientifically without merit; in short, a cheat to avoid accepting the logical alternative until evidence can be found.
Greetings
Greetings to one and all.
The purpose of this blog is mainly as a crutch for me, but hopefully it will be of use to others as well. To begin with, I am a terribly unmotivated writer, so by forcing myself to write frequently, I hope to spur myself to be more productive in the writing that comes with being a scientist.
Secondly, there is a lot of research that says that passing information repeatedly through one's brain (i.e. repetition) is the best way to remember something, so if I write about science that I find interesting, the more likely I am to remember it later, as opposed to saying, "Oh, that's interesting," and then tossing the paper on the mountain of other papers to be forgotten.
Thirdly, it is easy to get caught up in the daily grind of research and classes and the daily living of life and forget to read as much as one should. So, by having a forum that is impatiently waiting for me to say something, I will thereby shame myself into searching out information to talk about. This actually isn't that hard as there is ample cool science stuff coming out all the time and this gives me a place to say, "Wow, this is so cool, look at this!"
Be warned that my science interests are hardly limited to my own research (which only a very few other people besides myself would be particularly interested in, most people just think "gross" and walk quickly the other way), so topics here will cover a wide range of topics. There will be lots of paleontology stuff, but I will be ranging rather far afield. Think of it as an opportunity to broaden your horizons.
The purpose of this blog is mainly as a crutch for me, but hopefully it will be of use to others as well. To begin with, I am a terribly unmotivated writer, so by forcing myself to write frequently, I hope to spur myself to be more productive in the writing that comes with being a scientist.
Secondly, there is a lot of research that says that passing information repeatedly through one's brain (i.e. repetition) is the best way to remember something, so if I write about science that I find interesting, the more likely I am to remember it later, as opposed to saying, "Oh, that's interesting," and then tossing the paper on the mountain of other papers to be forgotten.
Thirdly, it is easy to get caught up in the daily grind of research and classes and the daily living of life and forget to read as much as one should. So, by having a forum that is impatiently waiting for me to say something, I will thereby shame myself into searching out information to talk about. This actually isn't that hard as there is ample cool science stuff coming out all the time and this gives me a place to say, "Wow, this is so cool, look at this!"
Be warned that my science interests are hardly limited to my own research (which only a very few other people besides myself would be particularly interested in, most people just think "gross" and walk quickly the other way), so topics here will cover a wide range of topics. There will be lots of paleontology stuff, but I will be ranging rather far afield. Think of it as an opportunity to broaden your horizons.
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