Over at Archosaur Musings, Dave Hone has been publishing Academics on Archosaurs in which various palaeontologists are asked the same five questions about palaeontological research – past, present and future. One of these featured Jerry Harris and Jerry made a wonderful observation regarding something that has been a continual bane of contention in palaeontology – the use of extant analogies.
When a dinosaur has been discovered, and has gone through the long process of excavation, preparation and description, then the palaeontologist quite often reaches an impasse when it comes to suggesting physiological and anatomical adaptions and especially behavioural patterns. Faced with this degree of uncertainty palaeontologists’ often make inferences based on similarities in animals that they are familiar with today – the extant analogy (EA).
When the EA demonstrates adaptions that the fossil taxon does not then these missing properties in the fossil taxon can then be the object of an inferred analogy. The problem with this, however, is that analogical inferences are often guided by established constraints that allow the palaeontologist to make selected inferences – and herein lays the problem. Just what these constraints are is a matter of conjecture.
This suggests that more palaeontologists are likely to make confident assumptions when they recognise the EA and fossil taxon as similar as they are to disregard them. Of course this is a natural thing to do and we have all done it – we want to see the similarities so that we can envisage our fossil specimens as living breathing animals. This is because common characteristics increase the recognised similarity of two species whereas different traits reduce the recognised similarity. And the more characters shared between the two species, the stronger both our inferences become and similarity appears to be.
Of course, this is not a criticism of, for example, the extant phylogenetic bracket – not by a long way but it does not hurt to be always questioning ourselves when we make perceived assumptions because of similarity. We can hypothesise about various inferences based upon characters found in the EA which are not preserved in the extinct taxon but this must always be quantified by additional phylogenetic, morphological and osteological analysis and, even then, there must be a further rigorous reappraisal of data before drawing any reasonable conclusion. And, even after all this, there will still be a degree of speculation.
Behavioural inferences are speculative in the extreme. Similar physical adaptions and characteristics may appear to suggest a similar lifestyle for an extinct taxon – take the heron-like analogy for Spinosaurus in Planet Dinosaur. But this is completely untestable speculation and, as Jerry Harris stated, non-avian dinosaurs are a totally unique group of animals with no real extant analogues and so the challenge is to concentrate on what made the dinosaurs unique within a much bigger framework that includes everything from the animals themselves to the environment they lived in.
Moving on and Jon Tennant over at Green Tea and Velociraptors recently made a critical appraisal of the very well publicised paper that suggested that methane produced by sauropods could have contributed to a global temperature increase in the Mesozoic. Plenty of other people have made their feelings clear regarding this paper and I’m not about to review it further but Jon made the following observation:
“The amount of times statements are preceded by ‘could have’ ‘suggests’, ‘estimates’, ‘likely’, etc. is an immediate trigger for concern. There’s nothing actually concrete in the paper.”
And yet these words and phrases are universally used in the world of paleontology and with good reason. I suspect that no matter how solid your research may be, how thorough the data analysis is, even how testable a hypothesis may be , it is natural for authors to quantify any statement they make – especially when it is presented to an ever growing audience that has an insatiable need for more and more knowledge. An ever more critical audience too it has to be said.
As a blogger I have become very aware of this phenomenon. So when I review a paper or discuss a conference I do indeed tend to use the words “suggest”, “hypothesise” or “likely” purely because to state anything as fact is guaranteed to set you up for a grilling from a very discerning audience. I still have the odd lapse but I can rely on my readership to point it out - that’s for sure.
Even when I feel certain that a theory is probably correct, and ascribe to it with confidence, I will still describe it as likely or possible. For me, if some research appears correct in my eyes and I can see how the theory was arrived at, I am very likely to subscribe to the premise of the paper and be confident in its testability. However, if a subsequent theory by another palaeontologist is able to disprove the first paper and I am satisfied with the data analysis presented, then I am happy to ascribe to it from that moment on. This does not mean that the previous paper suddenly becomes insignificant or useless but further research has built on the original findings presented and the new paper often uses this data to formulate a new premise. This is the very crux of good science and long may it continue.
It is also another reason not to use those words which state theory and hypotheses as fact and it makes sense to be neutral and impartial. I am, on occasion, shocked by the aggression shown by some paleontologists’ to another’s research when it is published. I’m not talking about these odd papers that crop up from time to time that we all know are full of, how shall we say, dubious information but those papers that are from reputable researchers, which have gone through the peer review process and published in entirely legitimate journals. This is unfortunate and, in my eyes, entirely unnecessary. Constructive criticism yes but when it degenerates into a slanging match in the palaeontological public eye then I’m not interested - what’s the point in that?
Which brings me to my final thought for now and it directly relates to the previous point. I have been asked a couple of times why I do tend to sit on the fence and that I never actually criticise anyone. Well that’s not strictly true and I learnt my lesson a few years back when I opened my mouth a bit too freely on a couple of occasions and was promptly reprimanded by a couple of seasoned palaeontologists – and rightly so (thanks for that guys – you know who you are).
When I took a step back and thought about it I soon realised the truth. Who am I to openly criticise someone’s research that, in all probability, took years to produce? These researchers had endured years of sacrifice, toil and expense to get where they are today and produce the literature that I love to read. Not for me to criticise anything these palaeontologists’ do and more power to them I say, even if I do not necessarily agree with the data presented – they have my utmost respect. I am reminded of the old saying “I do not agree with what you say but I will defend your right to say it”.
However, that does not mean there are those papers which, in my humble opinion, are pretty average and where, again in my opinion, the data provided does not necessarily add up. But this paper is still a valid and peer reviewed contribution to the literature and must be respected as such. There are exceptions and I have no qualms about savaging those so called publications such as the notorious kraken and aquatic dinosaur debacles. But then, in these extreme circumstances, we all do don’t we?