This post originally appeared at: http://the-briefing.com/a-new-power-is-rising/
People always under-estimate the power of the fossil record. There has always been this stigma surrounding it that it is too poor, or too biased to read ‘properly’, and is consequently of no use. I still hear this quite a bit, and there are a couple of reasons for it.
Over the last ten years or so, there has been a substantial increase in the methods we can use to interpret the fossil record, based on an increased understanding of the interaction between large fossil data sets, the geological record, and the way in which we as humans have sampled these archives. This has dramatically changed the way in which we think of, and use, the fossil record – we see its imperfections, but we also know how to compensate for them, making the fossil record a new rising power for understanding biological patterns in deep time.
However, this has not really been picked up in the media. Nor has it really been utilised by other related branches of science. Molecular systematists still hail the ‘DNA revolution’ as making the fossil record obsolete, when in fact the truth couldn’t be further away. Molecular systematists need fossils to calibrate their evolutionary trees, and make them, well, useful. DNA tells us little about extinction, and nor does it give is information on what animals of the past were actually like. Without fossils, we would know little about evolutionary rates, or the timing of origins of major groups of animals, such as those around us today.
Feathered dinosaurs are the bane of many a palaeontologist. Nine times out of ten, when asked what we do, the response is either ‘like Ross from Friends?’, or ‘Dinosaurs?’ The media are the sole perpetrators of this misconception – every time a new feathered dinosaur is found, it makes the front page headlines, when in fact scientifically, they actually tell us very little individually, and only then about a particular group of animals.
So why do these two points matter? Well, in a time of squeezed research budgets, many other fields of palaeontology that are developing mature applications that can be used in, for example, climate prediction or conservation efforts by telling us how animals respond in time to environment shifts, these are being dismissed in favour of perceived ‘news-worthy’ headlines. In fact, and scientific reality, things couldn’t be further from what we, as a field, would like.
We’d like to show people that we are doing relevant science, that their taxes are going towards something functional, something useful, and something important. Yeah, new dinosaurs are cool, but the representation that we have in popular society and the media is totally misleading. The over-sexifying of aspects of palaeontology is hurtful for our community. What needs to be communicated more are the important aspects of palaeontology, such as macroevolution, biostratigraphy, or palaoeclimatology.
So this new wave of palaeontology is actually more commonly being called palaeobiology – instead of grey-haired men sitting in labs doing taxonomy, much vigour is being pumped into new fields such as functional morphology, mass extinctions, or biomechanics. We now know more than ever thanks to new technologies, new thinking, and new methods to test questions we couldn’t even dream of asking 30 years ago.
Bringing this back to biodiversity, and the incomplete nature of the fossil record, we now know that historical trends of biodiversity are closely tracked by the availability of fossils in the geological record – we call these sampling biases. It makes sense to think that if we have more fossil-bearing rocks to sample from, we get more species, or more species’ occurrences, and in general this is what we see.
While some see this as a way to dismiss the value of the fossil record, it has, in fact, spurred on a new wave of understanding of fossils. For example, one modelling technique commonly used now creates a measure of biodiversity based on an assumed perfectly sampled record, which if we take away from an observed measure of biodiversity, we get what is called a residual diversity – the component of biodiversity which cannot be explained by sampling biases, and reflects biological patterns. This is but one of a host of methods currently being used to disentangle trends in biodiversity in deep history, and reveal much to us about the shifting dynamics of diversity, and its distinct coupling with the environment. Clearly, such discoveries are of considerable more worth, both to scientists, biologists, zoologists and conservationists in this rapidly changing world of ours.
I guess in some ways this is subjective – some might see the significance that a new dinosaur brings in terms of attention more valuable to the field, but all this does is perpetrate the misconception that palaeontologists just, well, dig dinosaurs.
This has, to a degree, reinvented the fossil wheel, and with this has its dissenters – but dissent is good, it helps us to strengthen our theories, and seek new ways to solve old problems. Palaeobiology has never been more dynamic as a field, and it’s time that we cracked out of the dinosaur-chrysalis and showed everyone what a colourful range we’ve been hiding. Of course, this involves more engagement between scientists and science reporters, which is probably something every field could ask for more of. I just know about palaeontology, and I hope this conveys why I think a paradigm shift is needed for us all.
Now witness the power of this armed and fully-analytical fossil record!
Jordi Paps
Hey Jon,
Congratz for this post, I really enjoyed it! However, at the risk of being nit-picky, I completely disagree with some of the things said here.
“Molecular systematists need fossils to calibrate their evolutionary trees, and make them, well, useful.”
I think this statement it is completely misleading and inaccurate. Phylogenetic trees are hypothesis of evolutionary relationships between organisms, they have little to do with time calibrations or are made “useful” (ugh?) by them… some researchers choose to use trees to calibrate cladogenetic events, but it is not the aim of a phylogenetic tree.
“DNA tells us little about extinction…”
I disagree again, any phylogeny (molecular or not) can say many things about extinction, see for example http://www.cell.com/trends/ecology-evolution/abstract/S0169-5347(13)00230-9
“DNA … nor does it give is information on what animals of the past were actually like.”
Half-true, while not providing direct information on their exact appearance it can tell us many other things about past living beings. I have not the time now to go over the results from ancient DNA studies, comparative genomics to reconstruct ancient genomes that tell us what biological functions were available to the ancestors, the classification of diet components through DNA, and other DNA-based methods that fantastically complement paleobiological insights.
I hold Paleobiology in high esteem, and I have never heard any of my molecular colleagues saying the “fossil record is obsolete”; maybe there is a samplign bias and you have met the ones that were wrong, heheheh! I do not think there is any need to belittle other areas of research to make Paleobiology look important, I think it is a central area of evolutionary biology.
Finally, I completely understand your point about avoiding a “dino-centric” or “fossil-centric” depiction of Paleobiology to non-scientists. I agree that Paleobiology is more than that. However, I think some of findings in the field with the highest scientific impact come indeed from plain old school fossils (i.e. first stromatolites in Strolley Port Chert, Grypania spiralis as first eukaryote, Bangiomorpha pubescens as first multicellular, the Ediacaran biota, the Cambrian fauna). So while I agree with you that we should explain that Paleobiology is more than fossil hunting and “feathering” dinosaurs by men with grey hair, maybe we should also try to show people why old plain fossils are also very cool and important.
Keep the good work!
Jordi
Jon Tennant
Hey Jordi,
Wow – now that’s a comment and a half – thanks!
So when you consruct molecular phylogenies, you need fossils to calibrate higher level nodes, for example when using relaxed clock methods. For example, see this recent paper by a colleague: https://www.academia.edu/4115742/Arthropod_fossil_data_increase_congruence_of_morphological_and_molecular_phylogenies Fossils make molecular phylogenies considerably more precise, that’s just how it works in a logical and empirical sense.
Molecular phylogenies can tell us about hypothetical extinctions – yeah, you can simulate it as much as you want, but last occurrences (when acknowledging the Signor-Lipps effect) of fossils are the only real measures of extinction. Thanks for the paper though, will have a read.
Not sure about the next point really. There’s still a lot of room for research into molecular function, and obviously the majority of fossils we have, and fossil lineages, don’t have DNA, but we can still use these to infer functions such as feeding style or physiological factors.
Perhaps I may have been over-pedantic with the opinions of molecular systematists, but time after time I go to conferences where the fossil record is completely ignored in phylogenetic studies, despite its overwhelming value.
I don’t mean to belittle other areas of research either, I’m just saying these areas need to justify their real value, and that there are multiple other fields which, in my opinion, deserve more attention either along side of or instead of, you know, feathered dinosaurs. I’m sure (and know) many palaeontologists would agree!
And yeah, agree with your last point entirely. Think about this stuff from a funders perspective too.
Cheers,
Jon
Jordi Paps
Hey Jon,
Jordi Paps
Hey Jon,
I was going to reply here, but then I realized that my beef is about the misrepresentation of molecular phylogenetics in the post, nothing to do with the main theme of your post (biased outreach). I think this kind of concerns should be addressed in a public forum (I am complaining about the depiction made of an specific area of research, the same as you do), but I will send you a private email with my comments and then you can feel free to post them or not.
Cheers
Jordi
Cheers
Jordi
Jon Tennant
Aha, yes, that you may be right about. I’m only going off my limited experience hanging around molecular systematists, particularly at the NHM in London and with ECRs at conferences.