Okay, I know all I am doing is fueling the perpetuation of this kind of crap on TV.
That said, I was bored, and one of the few cool things about The History Channel is that it allows folks to watch their shows online.
The latest one was called: Bloodiest Battle; the story of the Cleveland Lloyd Quarry.
Well, the JFC version of what happens.
Anyway, there were, as usual, a host of annoying offenses in the show. Besides the ever annoying “loud dinosaurs” (i.e. all the dinosaurs couldn’t stop roaring), there was also the requisite rampant speculation on the social life of Allosaurus, the ecological relationship between Allosaurus and Ceratosaurus, and various anatomical flubs that continue to send out the message that The History Channel only hires the “talking heads” so they can appear scientifically legitimate.
Anyway, the only reason I am bringing this one up is because the most egregious error in the entire program (in my mind, at least) was the absolute statement from “Dinosaur George” Blasing that “all the evidence points to these animals being warm-blooded.”
That is bull-shit with a capital B.
Er…Bull-Shit.
There is no, I reiterate NO consensus on the thermophysiology of dinosaurs. That is true for all dinosaurs. All the evidence used so far has been ambiguous at best.
Furthermore, a “cold-blooded”Allosaurus is going to have the same overheating problem as a “warm-blooded” Allosaurus.
The problem has nothing to do with thermophysiology. It has to do with big animals over-exerting themselves in a hot environment. Dinosaurs were reptiles, and like all reptiles, they had a very limited means of removing heat. No sweat glands, and no real bare skin.
One thing that Allosaurus and other saurischian dinosaurs may have used to keep cool is their air sac system. Air sacs in birds do not lead to their high aerobic capacity. That is accomplished through the flow through system that the air sacs created, where oxygen is sent only one way (vs. the dead end bellows way that mammals and reptiles use). The perfusion of extra air sacs all over the body does nothing to add to endurance in birds. What it does do, though, is lighten the body and provide a spot for heat to dump from deep in the body. It is honestly quite likely that this is was the main impetus for air sac evolution in dinosaurs, and its consequent exploitation by their avian descendants.
This explanation would certainly have been a more scientific answer to how Allosaurus kept cool instead of pulling that antorbital fenestra radiator idea out of wherever “Dinosaur George” found it.
I don’t like absolutism in science programs anyway, but this type of absolutism is what lead to the general public thinking, erroneously, that scientists have discovered dinosaurs to have been warm-blooded. All this winds up doing is creating a false concept of dinosaurs that winds up getting shot down when new students enter the field and find that dinosaurs weren’t the super hot-blooded beasts they thought they were.
Plus, it’s just annoying when some fanboy says that being “warm-blooded” is one of the fundamental differences between dinosaurs and other reptiles.
Okay, I’m done venting.
Next episode involves some mythical beast called a “megalodon” (they must mean Carcharocles/Carcharodon megalodon). I hear that, at 15 meters (50ft) in length, it was the size of a jumbo jet and had to eat a tonne of meat a day to keep going.
Yeah, definitely sounds like something worth missing!
A few weeks ago the History Channel aired their first in a twelve part series on prehistoric creatures.
Now, being the History Channel – a subsidiary of Discovery ChannelA&E Networks – one would expect this series to detail some aspect of prehistoric life. Well that it does…sort of.
The series is called: Jurassic Fight Club. Many of you have probably already watched the first three, or four episodes, but for the uninitiated the premise is as follows:
Imagine all 4.6 billion years of prehistory as being one planet wide cage match somewhat akin to Primal Rage. Each week two animals (usually dinosaurs, but there are the occasional mammals) are pitted against one another.
Each hour long show is supposedly based off of a real fossil site. For instance the first episode was about a Majungasaurus skeleton that was found with bite marks of another Majungasaurus (erroneously referred to as “Majungatholus” despite paleo-consultant disapproval). One of the recent ones involved the infamous Tenontosaurus tilletti / Deinonychus antirrhopus fossils (a find with one large, dead T.tilletti and a few dead D.antirrhopus nearby. One of the first bits of evidence in favour of pack hunting behaviour in some theropods).
The show sets the “battle premise” and then seeks to justify its reasoning by cutting to various paleontologists for their take. The paleo crew is fairly diverse and include: Dr. Thomas Holtz Jr.Dr. Larry Witmer and Dr. Phillip J. Currie.
Okay, so maybe all that doesn’t sound so bad to some of you, but what may seem okay in theory has turned into an utter failure in execution.
Let me state up front that I immediately left this series for suck back when I first heard the title. It sounded like just another useless “documentary” that is little more than an excuse to watch two CG animals fight each other in order to satisfy some sophomoric need to watch things fight.
Still, there were proponents of the series (namely the paleo folks that worked on it) that urged the most skeptical of us to give the show a shot. As such, I refrained from commenting on it until now.
Four episodes in and now even the scientists who helped on it are starting to back away.
Honestly who could blame them. The show uses minimal information from the actual scientists. The shot of Dr. Witmer comparing theropod maxillae is continuously reused, and I could swear the show spends more time on the non-professional guys than they do the actual scientists.
This is a problem because it is the non-professional crowd (one fellow in particular) who really bring the show down.
The show features the likeness of one Dinosaur George Blasing. A quick perusal of his qualifications finds him to be little more than a particularly successful dinosaur fanboy. He apparently makes his living by talking about how cool dinosaurs are, to elementary school children. In effect, he is little different from Dinosaur Don Lessem, who writes books about dinosaurs for children.
Now don’t get me wrong. There’s nothing wrong with being an amateur, or a big, but non-professional, dinosaur fan. The problem I have is with History Channel essentially letting the fanboys run the show. This is supposed to be an educational program. History Channel is supposed to be the repository for all things historical. As such, it should be held to a higher standard than, say ABC, or Fox. Yet, here we get to witness the production of another terrible program that only seeks to snatch eyeballs. It offers practically no educational value.
Frankly that just ticks me off. Jurassic Fight Club is about as terrible as Animal Face Off was (another Discovery Channel property that not only embarrassed the subject matter, but also the scientists involved with it, by forcing them to give trash talk to one another).
The question that shows like JFC leave me asking is: what audience is it meant for? By seeking out professional paleontologists for their input, one would assume that the makers were looking for scientific accuracy. This, in turn, suggests that the goal is to pass knowledge on to their viewers. Yet, if one can slog through the first episode they will find themselves assaulted with absolutes left and right, tonnes of MTV style quick takes and replays, and a metric tonne of speculation. Each episode ends with Dinosaur George giving “his take” on how the whole story unfolded (complete with the CG animation). Now this sounds like nothing more than Godzilla style popcorn entertainment.
So which is it? Is JFC trying to be a documentary, or a popcorn flick?
By trying to do double duty, it comes off as more of mockumentary. A documentary that seeks to mock the subject material in which it presents. When done right, mockumentaries can be great (e.g. This is Spinal Tap), but in cases like this, where the parody does not appear intentional, the result is more of a slap in the face to those of us who do work in the field. To ask for professional advice and then completely ignore it, is a huge insult to both professions. The History Channel people should know better.
One question that is left from all this is: must we sacrifice scientific accuracy for entertainment, in order to get the knowledge across to the viewers?
As one person had mentioned on another forum: if scientists were to get the documentary that they wanted, no one would watch it.
Pardon me if I decide to call bullshit on this one. If one wants to see a documentary that is designed in a way respectful of the subject matter, one need only look at PBS’s NOVA series. Rarely does NOVA falter in their presentation style. Because of this consistent high quality the series tends to be lauded by many in the fields of science.
Okay, so maybe NOVA is a fluke. Besides, it’s on PBS and we all know how small and concentrated the PBS demographic tends to be. Are there any other examples?
Plenty.
David Attenborough – King of great documentaries
If one really wants to see how to make a series of successful and scientifically sound documentaries, one need only to look over to the UK, and the BBC. In the realm of documentaries, the David Attenborough docs reside in the upper echelon of quality. Not only are Attenborough’s documentaries well done, and accurate, but they are also popular. Planet Earth, one of the latest Attenborough docs, was the most watched cable show of all time. Discovery Channel pulled in 100 million viewers when it first aired in the United States. That is huge for a major network, much less a cable network (Discovery’s average prime time ratings are around 5 million viewers).
So not only does a scientifically sound documentary bring in the audience, but it can bring them in droves. When BBC released “Life in Cold Blood,” it was an event in England, bringing in more viewers that the average drama.
If we head back to the states, we can look at an old staple of children growing up in the 1990s; Bill Nye the Science Guy was a show that garnered a large and devoted fan following. Bill Nye was not only a great presenter and funny comedian, but he was/is also a real scientist. Though the show did its best to avoid using large words (for its young demographic), the show repeatedly and successfully showed off how awesome science was and how amazing the real world is.
Bill Nye – Champion of science education
You know why I think these shows did as well as they did? Because they didn’t dumb stuff down. There was no push to show the flashy stuff in order to maintain audience attention (equivalent to showing something shiny to distract a cat). The BBC documentaries, Bill Nye and NOVA all respected the intelligence of their audience, and the audience reciprocated by showing up in droves. People from all walks of life enjoy a good challenge. Today’s current documentarians would benefit from remembering this.
So for all those scientists who are asked to participate in the next big Sci Fi/Discovery Channel/ABC show/ whatever documentary; I say don’t fear speaking your mind on the importance of keeping the science up to snuff. If the filmmakers start bitching about having to “keep things simple” or removing the science for the sake of “the story,” just tell them:
That’s not how David Attenborough would do it.
~ Jura – who will probably never get a consulting job on one of these shows.
A new paper in Nature has discovered that at least one known virus strain can get sick.
The virus in question has been dubbed: mamavirus. The name stems from the giant size of the virus. Mamavirus is bigger than some of the smallest bacteria, with more than 900 genes. The neat thing, though, was not so much its large size, but the presence of a smaller “satellite” virus deemed Sputnik. Under “normal” circumstances when a mamavirus infects a cell it uses the proteins its genes encode, to hijack the cell’s metabolism and thus create more viruses. When Sputnik is around, though, the rules change. Sputnik hijacks the hijacked machinery, resulting in malformed versions of the mamavirus.
In human world terms, Sputnik gets mamavirus sick. Sputnik is, thus, the first example of a virophage – a virus that infects other viruses.
All in all a fascinating find; but what of the broader implications of the article. If mamavirus can get sick, then does it qualify for life?
There are, or used to be (more on that later) five criteria for life. They were:
Movement (internal, and/or external)
Reproduction
Growth
Metabolism
Adaptation
In order to be alive, a candidate must satisfy all five criteria. So plants, animals, fungi, protists and bacteria all passed with flying colours. Rocks fail, as they neither metabolize, adapt, or reproduce (they can grow and do evolve though).
Biochemists in the crowd might point to prions. They do reproduce, but they don’t grow, adapt (resist, but not adapt), metabolize or do anything else like life. For the most part, prions are just malformed proteins. They reproduce by infecting nearby proteins; a case more similar to limb rot, free radicals, or erosion than true reproduction.
Viruses, on the other hand, get real close. They reproduce, grow, move and adapt. The one thing that they don’t do, is metabolize. In order to metabolize, a virus must steal the metabolic “machinery” of another living organism. Because viruses lack this fundamental requisite, many biologists and biology textbooks place them just outside of life.
Think about this though. A virus acts just like other living things. It just needs a little help to do some parts. Viruses are not self sufficient, but that shouldn’t relegate them from the status of alive. There are lots of animals today that must steal the resources of others in order to survive. We call them parasites. One of the evolutionary hallmarks of parasitism is a streamlined genome. Depending on the degree of parasitism going on, a parasite could remove limbs, sensory organs, digestive processes, and even some reproductive material. In effect, a highly evolved parasite can easily be mistaken for a primitive relic.
Tapeworms: primitive, or advanced?
So too with viruses. What if they were cells that reduced their extraneous evolutionary baggage so much that they now fall outside of the traditional criteria for life? There is currently no way of knowing if this is true, but at the very least it would seem that viruses should warrant an honourary placement within the realm of life.
The argument oscillates back and forth between life and non-life. This is good as it forces us to look harder at the criteria for life.
However, there is another group out there that tends to poo poo all this semantic talk. They are the same group that thinks the arguments over Pluto’s status as a planet are useless (because they think the concept of planet is useless), or that species are a pointless arbitration. In this case the argument is that the criteria for life are all arbitrarily chosen. That life is a continuum from non-living to living, with no real demarcation, and thus no real value in being defined.
I disagree wholeheartedly. There is an obvious turning point between what is alive and what is not. If viruses are skating the edge of this line then all the better for us. Defining what constitutes life is extremely important. If we don’t know where this line lies, then we are unable to determine what makes something alive to begin with. What is it about a cell that is so unique compared to a small rock? What is so special about this particular chemical makeup?
From a deep philosophical view, the definition of life would seem all the more important. If one wants to find out what makes humans unique, then it would help to know what it is that determines their life in the first place. For bioengineers, knowing the criteria for life, gives one a chance to actually create life. Abiogenesis scientists (those who study the origin of life) would be lost without some kind of definition for what it means to be alive.
I just don’t understand how some scientists, of all people, can make these arguments about the uselessness of arbitrary definitions. How do they expect people to talk about these things if there is no way to name, or categorize them? Conceptual terms might come with baggage, but the instant definitions and criteria that they come with, more than make up for it.
Take the planet example. If two astronomers were talking about finding some new planet, I would immediately be thinking of a massive celestial body orbiting a star, and being large enough to be round. If, on the other hand, they were talking about finding some new dwarf planet, then I would imagine a smaller object that may, or may not be completely round and is probably not orbiting a star (at least not very close). Having a definition in place already, removes the necessity of figuring out how big, or how erratic the orbit will be. If the goal is to look for life, I can probably skip the dwarf planets and focus on the real planets.
From: Mike Keefe’s Denver Post comic
If we removed the term planet altogether, then what would astronomers talk about finding? They found an object. How big is it? What kind of orbit does it have? Is there an atmosphere, or a star? Many of these questions can be answered quicker by having the definitions that we currently have.
All the more reason why this urge to purge useful arbitrary definitions from the scientific lexicon, is disturbing. I would like to know what proponents of these ideas suggest we use in place of these names. To date I have heard no alternative brought forth.
Dr. Pausch, and all those who followed him, knew that this day would come. Though many had hoped it would be much further in the future, the outcome was no less inevitable. While it is sad to see him slough this mortal coil, it is more important to remember how he lived and the lessons that he taught us along the way. Dr. Pausch may be gone, but he has left his mark in history, and shown us all the importance of living a good life, and following our passions.
“…we don’t beat the Reaper by living longer. We beat the Reaper by living well.” – Randy Pausch
The Telegraph had a report today on a unique event in Africa. Hal Brindley, an American Wildlife photographer, happened to be in the right place in the right time for this to happen. The shots come from Kruger national park.
Photo taken by Hal Brindley and destributed by Solo Syndication
The photos show a leopard (Panther pardus) taking out a Nile crocodile (Crocodylus niloticus). The croc is smaller than the leopard, but the results are no less shocking.
Leopards, and most big cats in general, don’t go after crocodiles as a normal routine. Not only do the felines run the risk of becoming the hunted, but even if they do win (like this leopard did), there is really not a lot of meat to go around. Much of it is locked away by the bony osteoderms.
The only time I have seen a leopard take out a crocodile, was in a case where both animals were slowly starving and dehydrating. The crocodile died first, and the leopard took advantage of the free meal.
As one can see in the photo, this leopard wasn’t exactly starving, so it is hard to imagine desperation being the cause of this attack. The article also mentioned that the leopard attacked the croc on its own turf. Both situations are very unique, and make the fact that the leopard won, all the more amazing.
There was no run time given for the battle, so I’m not sure how long it lasted. Judging from some of the shots though, it must have been intense.
Oh hey look. An image that didn’t get its formatting messed up by WordPress.
So to speak. If you haven’t seen all 3 acts yet, make sure to head on over to the official site and watch them. They’ll only be there until July 20th. After that, they will be pulled off the (non-bittorrent) net, for work into a DVD.
Overall I had a positive experience with Dr. Horrible’s sing along blog. The songs were catchy and the story was on par with something from The Tick. The final act does take a hard downswing into the realm of drama. This is rather typical for a Joss Whedon series. If one was a fan of Buffy, Angel, or Firefly, then this wont’ be too surprising. Unfortunately the short runtime of the show made the dramatic shift a jarring one.
Early reviews seem to be polarized. Some people liked it, while others felt Joss dropped the ball. Personally I enjoyed it. I like these types of endings more than the more typical “Disney” endings that permeate our current pop culture. I wish that the acts were a little longer though.
Some favourite moments from the show include Captain Hammer explaining “the hammer.”
Dr. Horrible getting all megalomaniacal before signing off from his webcam in act II, only to sign on a second later after finding out who some of his audience members are.
The sneak peak of the league of evil, including the reveal of bad horse (very reminiscent of The Tick).
All the actors did a fantastic job with their roles. It’s always a blast to see the actual actors doing the singing. I did feel that Felicia “The Guild” Day, was underutilized in the show. For the most part, she just played the girl in the middle. It would have been nice if her part was a bit more fleshed out.
Still, I’m sure that most of these folks got to add one more talent to their resumes.
Bonus win points to Joss for included former Buffy writers: Marti Noxon and David Fury (whose last onscreen singing was the Buffy musical).
In the end, it was a neat story. I’ll be curious to see where Whedon and his crew take it from here.
For all those playing the home game, here is the story thus far:
Reptilia, the group, was created back in the early days of taxonomy. Its coiner, Carolus Linneaus (upon whom we get the dominant form of classification today), created the group to house all the critters that were neither mammalian, nor avian. Reptilia was originally a wastebin that housed all extant reptiles, as well as spiders and sharks.
Over the decades, classification schemes became more refined and the definition of Reptilia became more restricted until it eventually resulted in the definition we have today. Namely that group that incorporates snakes, lizards, turtles, crocodylians, and tuataras. A group defined (or once defined depending on ones systematic leanings) as a collection of animals all sharing epidermal scales, being bradymetabolic (or more erroneously, ectothermic), and sharing a series of skeletal affinities such as a small, or absent tabular, a large post-temporal fenestra, a suborbital foramen and a supraoccipital plate that is narrow.
This definition worked and served herpetologists and paleontologists well for decades. Then in the 70’s a new classification scheme came along. Deemed cladistics, it focused less on shared characteristics and more on shared, derived characters.
For example: Humans have hair and five fingers. The five fingers are a shared character with all other tetrapods (terrestrial vertebrates and their secondarily aquatic descendants). Meanwhile the hair is a shared, derived character with mammals.
Obviously the terms shared and shared derived (or plesiomorphy and synapomorphy, in the technical sense) are going to depend on one’s frame of reference. For instance if one was going to look for a synapamorphic trait for humans compared to rats, then hair wouldn’t work. Fingernails and tailessness would. Compare humans to other apes and now these last two characters don’t work either, so one must look for something else.
So on and so on.
Cladistics had a rocky start, but was eventually accepted as the main means of determining evolutionary relationships. Though there are still a few staunch detractors, the overall view on cladistics is that it is the most true way of expressing evolution.
Since cladistics groups creatures by their shared derived characters, once one is on a branch of the cladistic tree, one stays there. Creatures can split from this branch, but they will always be retained.
See the following figure for an example:
Note how even though sharks, crocodiles and rabbits have all split from the vertebrate branch, they are still retained on it.? Since branches can infinitely split, there is no trouble with showing evolutionary relationships this way. It creates a view of evolution as a very thick bush; which is a fairly accurate representation of the results of this process.
In terms of phylogenetics, this is just fine.? Cladistics kicks butt.
Unfortunately, some ardent supporters of cladistics thought that this method might work well in terms of classification.
Now some of you might be shaking your head right now thinking that phylogeny and classification are the same thing. They are not.
Classification is the act of categorization. It is an arbitrary way for humans to order what they see in the world around them. We classify everything!
Cars are broken down into their manufacturer and their model. That’s classification.
Clothing is broken down into seasons, body type and general design. Once again, classification.
Google breaks search results into web, images, shopping, scholarly texts, etc. That is classification.
Now there are those liberal arts types out there that like to think that classification only limits our perceptions and creates unwanted stereotypes. While this is partly true, the alternative is a world without order. If our brains worked differently this might be fine, but our current neurological makeup is such that a chaotic hodgepodge of things without names and categories, only results in confusion.
Like it or not, we will always need to classify things. The trick is not to let the classification completely colour our perceptions.
Coming back on track, certain systematists felt that the all inclusive nature of cladistics would work well with classification. So new rules were implemented. From now on a group could no longer be defined by its characters. Rather, its definition would now be dependent on a completely arbitrary association of members.
For instance snakes are no longer classified based off of being limbless, and lacking both temporal bars among other things. Instead they are now defined as being the group that contains all members that evolved between boas and blindsnakes. To put it in a more exaggerated sense: boas are snakes because snakes include boas. This classification is completely circular and meaningless.
However it is also stable. 20 years from now, the definition of snake will remain the same. For some systematists the stability of the name outweighs its lack of substance.
Another rule enacted was that only groups that contain an ancestor and all its descendants would be considered a “natural” or “real group.”
On the outset this might not seem a problem. Humans are hominids. Hominidae includes us and a few other apes. No big deal. Birds, as neornithines, include every single bird you see flying around today. Again no problem.
But what about larger groups. Especially groups like Reptilia, that were originally believed to have given rise to numerous other groups (birds and mammals). What of Osteichthys, the group that gave rise to every land vertebrate today.
Starting to see the problem yet?
The old definition of Reptilia no longer held up. Reptiles excluded one of their descendants; the birds. This made Reptilia paraphyletic (ancestor and some of its descendants). In order to “fix” this alleged problem, birds would need to be incorporated into the meaning. The result: birds are now reptiles.
Well, in some circles.
This kind of all inclusive naming scheme has been met with intense resistance. So much so, in fact, that 30 years after its inception, dinosaur paleontology seems to be the only branch of biology that actually follows these rules. Every other field seems perfectly content with paraphyletic groups.
And hey, why not? Paraphyly makes perfect sense in terms of classification. It is much easier to grasp the concept that whales evolved from cows, rather than calling whales cows.
Alas this battle appears to be far from over. For whatever reason, Reptilia seems to be at the heart of the argument. Many herpetologists, ornithologists and paleontologists are perfectly happy with leaving birds out of reptiles. Other paleontologists are not, and continue to do away with the old definition. Some have even gone so far as to try and remove Reptilia altogether from classification.
So back and forth it goes. This continuous arguing has made things a little confusing for students of evolutionary theory. When it comes to classification the bickering between both sides can be enough to turn students away, or at least give them a headache.
Idealistic to be sure (I like the idea of a crocodylian and chelonian class), but controversial. CNAH decided that the most accepted version of reptile is one that doesn’t include either turtles or crocodiles.
As most web savvy “web 2.0” folks out there, I’m a huge fan of Joss Whedon.
The man gave us the incredible Buffy the Vampire Slayer series, as well as the equally impressive Angel, and the short lived (but well loved) series: Firefly.
Joss Whedon also has a hefty comic book following, with season 8 of Buffy, and the “spin off” series: Fray.
Currently there is only a trailer up through vimeo, but the mini-series is set to air on July 15th.
As a card carrying geek and Whedonphile, I am doing my duty and passing the word on to all other Joss Whedon fans.
Dollhouse is still a few months away. Till then, let’s help Joss stick it to the man (of course, he sort of is the man, but no matter), and support Dr. Horrible.
Actually, I’ve never thought that sauropods were grey. Mammals in general tend to be rather bland in their colour schemes. Reptiles don’t have that problem. With xanthaphores (yellow pigmented cells), erythrophores (red pigmented cells) iridophores (iridescent cells) and melanophores (dark pigmented cells), the range of colour available to reptiles, and by extension – dinosaurs, is quite vast.
That said, I always pictured sauropods as either a brownish green colour, or maybe a very pale blue (blue is generally rare in tetrapods, hence the thought of it being a weak blue).
But I digress.
I grew up during an interesting time for dinosaur research. Unlike the majority of paleontologists working right now I didn’t grow up learning about dinosaurs being slow and sluggish mistakes of nature. I also didn’t grow up with the “hummingbirds on crack” version of dinosaurs that is currently pervading popular culture. Rather, I grew up during that strange transitory phase of the Dinosaur Renaissance where dinosaurs were sometimes viewed as sluggish beasts and other times as racecars of the Mesozoic.
The result, I think, has been a slightly detached and objective look at how perceptions of dinosaurs have changed over time.
A “Brontosaurus” getting attacked by Allosaurus during a sojourn on land to lay her eggs. Ah, the classics.
One book I remember fondly was the Golden Book of Dinosaurs (shown above). It featured these beautiful drawings of dinosaurs living life as best we thought at the time. One picture that really stuck in my head, was a shot of two Brachiosaurus; one on land and the other so deep in a lake that one could only make out the crest on the head. I found that page to be so immersive and atmospheric. My knowledge of physics was not so good at the time, so it never dawned on me that this poor sauropod was basically breathing through a straw with its lungs separated by at least 2 atmospheres from the air entering (as best it could) the nostrils.
Then around the early nineties when Jurassic Park the book came out I started to note a distinct change in how dinosaurs were being portrayed. No longer were sauropods swamp bound behemoths. Now they were fully terrestrial titans that could not only support their weight on all four legs, but could even do so on 2 (well 3 if one counts the tail). It was around this time that Robert Bakker’s infamous “Dinosaur Heresies” started making the rounds.
Now, admittedly, Heresies came out in 1986 and the changing view of dinosaurs actually started in the seventies. However, it wasn’t until the early nineties that the full effects of Bakker’s work could truly be appreciated. If anything this gives one an idea of the kind of inertia one must deal when it comes to getting scientific ideas out into the public.
Again I digress.
It was around the early nineties when I first read The Dinosaur Heresies. The first few chapters were amazing. I had never seen dinosaurs portrayed this way. They walked better and were more active. In many ways they better fit the concept I had in my head all along.
Then I came up to the end of chapter 3. The thesis of this chapter was to explain why reptiles should not be viewed as inferior to mammals. In order to do so Bakker explained all the various ways in which extant reptiles outshine extant mammals. The end of the chapter features a beautifully drawn shot of the “panzer croc” Pristichampsus snatching a Hyracotherium (formerly Eohippus). The caption read:
Pristichampsus hunted during the Eocene Epoch, about 49 million years ago, but it was very rare, much rarer than big mammalian predators, proof that cold-bloodedness was a great disadvantage.
Predatory Dinosaurs of the World. Available on Amazon
That’s when the real thesis of the book hit me. The argument wasn’t: “Dinosaurs weren’t slow and stupid, because of the following.”
Rather the argument was: “Dinosaurs weren’t cold-blooded because the facts show the following.”
In order to pull dinosaurs out of the mire, Bakker had to change their fundamental thermophysiology. The general concept, that cold-bloodedness is inferior to warm-bloodedness, remained the same. This despite Bakker’s initial attempt to explain how “cold-blooded” reptiles outshine “warm-blooded” mammals.
Bakker’s book was just the start. From there, we had Adrian Desmond’s “The Hot Blooded Dinosaurs” (okay, technically Desmond was first by 7 years, but he largely stole Bakker’s work to make the book so it evens out) and Gregory S. Paul’s infamous: “Predatory Dinosaurs of the World.” Each new book taking the “dinosaurs can’t be cold-blooded” argument a little further. By the time we hit Predatory Dinosaurs of the World, Tyrannosaurus rex was running along at 40mph, dromaeosaurs were practically flapping around and every species of dinosaur was reaching adult size by between 4-10 years of age.
Sadly it was at this point that Jurassic Park was written. As hardcore fans know it was Greg Paul’s erroneous sinking of Deinonychus antirrhopus into Velociraptor that gave us the JP “raptors.” It was also at this point that the pendulum of dinosaur physiology officially swung the other way.
The thing that had always bugged me about this view of dinosaurs was the sheer lack of supporting data for it. The assumption was always that dinosaurs were so vastly different from “typical reptiles” that they had to have been doing something different. Yet when one looked at the actual data dinosaurs came out looking slightly odd at best. For the most part dinosaurs fit the reptile mold quite well. It was these elusive “classic reptiles” that didn’t appear to exist.
Most reptiles don’t fit the “typical reptile” mold at all. Yet despite numerous papers over the past 30 years depicting reptiles doing things normally thought un-reptile like (e.g. caring for their young, competing with large mammals, etc), most of this was dutifully ignored in favour of an older, more outdated view.
It was a problem that Neil Greenberg (1980) aptly called: The “endothermocentric fallacy.” Basically, the assumption that being an endotherm is inherently superior to being an ectotherm. Part of that superiority included the ability of endotherms to do everything faster and “better” than similar sized ectotherms. This problems with this way of thinking warrants an entire blog post to itself. So rather than get bogged down with this particular I’ll touch more on the endothermocentric fallacy at a later date. For now all that one needs to keep in mind is that the thinking of the time was that if dinosaurs were going to be active at all then they had to be endotherms.
By the late nineties we had the first evidence of feathers in a small branch of the theropods (Maniraptora). Birds were officially adopted into the dinosaur family tree and the fully endothermic concept of Dinosauria was completely entrenched.
The funny thing, of course, is that this dogmatic view of dinosaur metabolism was just as bad as the early 20th century’s “cold-blooded” swamp bound view. Sure dinosaurs were more active now, but the data supporting it was just as nebulous as the stuff that was used to keep dinos in the swamp.
Enter the 21st century, and the late…um, 0’s (does anyone have a name for this decade yet?). Biomechanic work on dinosaurs has started to reveal amazing insights into the physical limits of what dinosaurs could do, and the results have started to pull the pendulum back again.
Work by John Hutchinson and Mariano Garcia (2002) on T. rex showed that not only could T. rex not hit 40mph, but it technically couldn’t run either. A biomechanical assessment of theropod forelimbs by Ken Carpenter (2002) has shown that the “bird-like” dromaeosaurs could not fold their arms up like birds after all.
Work by Rothschild and Molnar (2005) on sauropod stress fractures showed no signs of rearing activity in sauropods, while work by Kent Stevens and J. Michael Parrish (2005) pulled the swan-like curve out of sauropod necks, placing things far more horizontally.
Work by Gregory Erickson and others (2001) on micro-slices of dinosaur bone has indicated that very few dinosaurs hit adult size in less than 15 years.
Now we have a new study by Lehman and Woodward (2008) which follows up on Erickson et al’s work and actually shows that even this toned down version of dinosaur growth is probably too fast as well. Lehman and Woodward focused on sauropods and studies on their bone microstructure. What they did was compare bone growth data to a well used equation for growth in animals.
Deemed the Bertalanffy equation; it states that the mass at any given age is an exponential function limited by the asymptote of adult body mass. This equation has been used extensively in studies on bird and elephant growth among others. An example of the equation is given to the right for fish.
When the authors did this they discovered something quite interesting. Instead of taking 15 years to reach adult mass, sauropods like Apatosaurus excelsus took closer to 70 years!!
Other sauropods measured took between 40 and 80 years! This is a substantial decrease in growth rate estimated before. Mind you this is data taken, in some cases, from the same piece of bone that Erickson et al had used. So one can’t suggest anomalous bones being used as the reason behind the surprising results. The authors also went to great lengths to take into account differences in mass estimations as well as allometric growth of body parts. In each case the changes had little affect on the overall outcome (in many cases, it made growth go even slower).
Now keep in mind we are talking about the time it took sauropods to reach full adult size. This is not the time taken to reach sexual maturity. Earlier studies by Erickson et al (2007) had already discovered that dinosaurs didn’t wait to grow up before engaging in sex, so there is no issue here of 80 year old sauropods finally “doing the nasty.”
What this does show is that growth in dinosaurs might not be as determinate as initially thought. An 80 year old sauropod might just have been close to the edge of its lifespan at this point (though the possibility of bicentennial sauropods does still exist). It also shows that dinosaurs had growth rates far closer to the realm of reality (before it was hard to imagine how an Apatosaurus excelsus was able to pound down enough food daily to add 13.6 kg of new mass a day. Especially given their small mouths).
Thermophysiologically what does this all mean? Were dinosaurs “cold-blooded” after all?
That’s one of those questions that will never be fully answered (short of a time machine). What this does do is pull dinosaurs ever further away from the “definitely warm-blooded” category and push them right back into the middle again. When/if the dust settles on this metabolism debate I suspect that dinosaurs will probably remain in the middle somewhere.
Of course while all of this is going on with dinosaurs we have other studies, like those from Tumarkin-Deratzian (2007) showing the existence of fibrolamellar bone growth in wild alligators, that are finally moving the rusty pendulum of reptile metabolism out of the “classic reptile” category and much closer to the middle.
So in the end dinosaurs will still probably wind up being “good reptiles.” Thankfully the exact definition of what that entails will have probably changed by then.
~ Jura
References
Bakker, R. 1986. The Dinosaur Heresies: New Theories Unlocking the Mystery of the Dinosaurs and their Extinction. William Morrow. New York.
Carpenter, K. 2002. Forelimb Biomechanics of Nonavian Theropod Dinosaurs in Predation. Concepts of Functional Engineering and Constructional Morphology. Vol. 82(1): 59-76.
Desmond, A. 1976. The Hot Blooded Dinosaurs: A Revolution in Paleontology. Dial Press.
Erickson, G.M., Curry Rogers, K., Varricchio, D.J., Norell, M.A., Xu, X. 2007. Growth Patterns in Brooding Dinosaurs Reveals the Timing of Sexual Maturity in Non-Avian Dinosaurs and Genesis of the Avian Condition. Biology Letters Published Online. doi: 10.1098/rsbl.2007.0254
Erickson, G.M., K. C. Rogers, and S.A. Yerby. 2001. Dinosaurian Growth Patterns and Rapid Avian Growth Rates. Nature 412: 429?433.
Greenberg, N., III. 1980. “Physiological and Behavioral Thermoregulation in Living Reptiles” in: A Cold Look at the Warm-Blooded Dinosaurs (R.D.K. Thomas and E.C. Olson Eds.), pp. 141-166, AAAS, Washington, DC
Hutchinson, J.R., Garcia, M. 2002. Tyrannosaurus was not a fast runner. Nature 415: 1018-1021.
Lehman, T.M., and Woodward, H.N. 2008. Modeling Growth Rates for Sauropod Dinosaurs. Paleobiology. Vol. 34(2): 264-281.
Rothschild, B.M., and Molnar, R.E. 2005. Sauropod Stress Fractures as Clues to Activity. In Thunder Lizards: The Sauropodomorph Dinosaurs. (Virginia Tidwell and Kenneth Carpenter eds). Indiana University Press. pp 381-394.
Stevens, K.A., and Parrish, J.M. 2005. neck Posture, Dentition, and Feeding Strategies in Jurassic Sauropod Dinosaurs. In In Thunder Lizards: The Sauropodomorph Dinosaurs. (Virginia Tidwell and Kenneth Carpenter eds). Indiana University Press. pp 212-232.
Tumarkin-Deratzian, A.R. 2007. Fibrolamellar bone in adult Alligator mississippiensis. Journal of Herpetology. Vol. 41. No.2:341-345.
