Scale, rotate, translate: on moving between fields of biology

I'm currently writing up abstracts for our lab to submit to a clinical meeting. Writing abstracts for a clinical meeting, especially as we work on an animal model, is a very different thing that writing abstracts for a basic science meeting. It's reminded me that my background is unusual compared to the people at this meeting (which I will be attending for the first time). As it turns out, the most active people I follow on twitter are also more clinically oriented, and in a discussion yesterday about animal models, the differences in our scientific backgrounds became stark. To put it simply, I think sea slugs are probably just as interesting and worth studying as humans. If you don't agree, go and read up on how they co-opt the poisonous organs of sea anemones for their own defence. Furthermore, as a evolutionary biologist, the answer to "does knowing about sea slugs help us understand humans" is "of course it does!"
In fact, until I started this postdoc, I'd never worked with live animals. My undergraduate research had involved a little collection of ecological field data (staring at birds through a telescope). My masters and PhD work, however, were all palaeontology. My research was collections based, meaning I spent my time in dusty museums rummaging through drawers pulling out fossilized bones and measuring them. The questions I was interested covered increasingly large time spans (several thousand years for my masters, several million for my PhD). Taxonomically, I looked at the European wide distribution of an entire species for my masters, and several entire orders of mammal for my PhD. It is big questions that excite me. Questions like: how do entire faunas respond to major episodes of environmental change? What is the role of functional specialization in the evolution of goups? How does variation in shape change through time? And, for me, the big one: how does variation in shape of body parts (mostly teeth and bones) relate to how animals function in their environments? I've spent a lot of the past five years thinking about these questions. They are, to me, fundamental to biology, and relevant to understanding organism function at any level. After all, every thing we observe in any organism (yeast, mouse, sea slug, hairless bipedal ape) is a product of evolution. Yet I now find myself writing for an audience that not only doesn't think about things this way, but actually views such thinking as suspect or frivolous. I am not saying they are wrong to think that way (I would only do that after a couple of pints). However, it does require that I learn a new way of talking and thinking about research, about organismal function, about biology, about science.
Given the above, you might reasonably ask what the hell I am doing in my current position. Well that brings us right back to the question of the relationship between organism shape and function. Most paleontological work doesn't test this relationship experimentally. Instead, we establish correlations between variations in shape and differences in ecology, often broadly categorized. A complex and elaborate suite of techniques for quantifying shape variation, correlating it with ecology, accounting for confounding variables such as shared evolutionary history and body size exist to look at this problem. Initially, this approach seemed very promising, allowing me to reconstruct functionally important behavior in fossils, and use it to understand evolutionary change on a macro (millions of years or more) scale.
Ultimately though, this approach became frustrating, because the fundamental premise remained untested. Specifically, I was looking at joints. Although I established that mammals that live in certain habitats have joints of a certain shape, I had no real data on why that might be. This is a major limitation of the comparative approach. And I realised that to fill that missing gap, I had to get data on how animals actually work. I would have to become an experimentalist. So, when through a stroke of luck, I was offered a postdoc in a lab that did just that, even though it was in a different system to what I was initially interested in, and was more clinically oriented than my previous research (admittedly, not difficult), I jumped at the chance.
The transition hasn't been hard, exactly, but it has been challenging. I have met people who are experimental biologists studying evolutionary questions who openly scoff at methods I have used and considered gold standard in my old field. Researchers who express serious misgivings about the validity of methods used to ask those big questions I was so interested in. I've had to learn that big questions can be different types of questions. Questions about complex systems, questions about organismal function, questions about disease etiology.
Ultimately, the research program I would like to pursue requires me to learn to think about questions at both these levels, and hopefully integrate them meaningfully. I've already lost my naivety with regard to many of the questions I wanted to ask about mammalian evolution. Answers will be partial, clues gleaned from the fossil record illuminating clues gleaned from detailed experimental work illuminating clues gleaned from broad comparative studies of living mammals. And many researchers are studying these systems with very different end goals in mind, to do with human health, that make them suspicious of my intentions and my seriousness if I harp on about the shared evolutionary history of all living mammals. It is a valuable experience I think to learn the complex languages of biological research, for all that it is uncomfortable at times.
But I assure you, as animals, humans are not special.