Max Planck famously said ‘science advances one funeral at a time’. Sadly there is still some truth to this: some scientists are incapable or unprepared to change their views despite overwhelming scientific evidence that they are wrong*. Outdated ideas often only die with their advocates. One thing I try to teach students is that it is alright to be wrong: many ideas turn out to be incorrect, lots of exciting hypotheses end up not being supported, and frequent promising avenues turn out to be cul-de-sacs. But that is how science progresses. We need to rule out some competing hypotheses in order to advance knowledge.
Years ago one of my colleagues was embroiled in a heated scientific argument with a collaborator over the interpretation of patterns in data he had published. My collaborator made an interesting point when she recounted the events to me. She felt that, in reality, the prize of winning the argument was small, as few people cared, and the argument had got heated for just that reason. As with any arguments that can be parodied as two bald men fighting over a comb, because the outcome will have little impact beyond the pride of the two protagonists, it can become bitter. But this argument got me thinking. It helps to have an enemy when making an argument, so perhaps the desire to cling to one’s misguided beliefs until death aids younger scientists in delivering a paradigm shift.
Paradigm shift is defined in the Oxford English Dictionary as a ‘conceptual or methodological change in the theory or practice of a particular science or discipline’. Most science, including ecology, advances incrementally rather than through major conceptual shifts. But there have been important breakthroughs in animal ecology in recent times, and most, to my knowledge, have not involved acrimonious debate.
Most of the major advances in ecology and evolution over the past decade or so have been methodological. The ability to assemble genomes is obviously one such exciting and important advance. This really has breathed new life into animal ecology. Some of the research is genomic natural history, with researchers reporting interesting facts about unusual aspects of a species’ genome. For example, it is fascinating that cod lack the MHC II genes, and identifying this surprising absence leads to the obvious, but thrilling, question: why? As we have begun to get a better understanding of the genomic differences between species, populations and individuals, we have begun to shed light onto how different speciation processes generate different genomic signatures. As the cost and ease with which genomes can be identified increases, it is clear that our understanding of the processes underpinning evolution, and the mechanisms that convert them into patterns written in the genome will exponentially increase.
Another remarkable methodological breakthrough is the advent of wearable tech for animals. This has provided important insights into animal behaviour, including detailed information of the routes animals use to migrate, how they use space, and how they interact with one another. In addition, technological advances now allow us to measure heart rate and metabolic rates in free-living animals, as well as accurately determining their diet. Such advances are important from both an ecological and conservation perspective. Clearly understanding how animals behave is useful when planning conservation strategies. From an ecological and evolutionary perspective it is remarkable quite how much variation there is at all levels of biological organization – from between individuals to between populations. Understanding how this variation is generated, maintained and its consequences for ecological and evolutionary dynamics is currently at the heart of animal ecology.
One of my first papers introduced what I thought of as a methodological advance. My coauthors and I developed a statistic we called mean d2 based on the squared difference between microsatellite allele repeat lengths at a locus. We proposed that the measure captured two processes: recent inbreeding as well as mating patterns from deeper in the pedigree. It got widely used, often incorrectly as just a measure of inbreeding. The measure is at best very noisy, and it is quite challenging to interpret what it really captures. Subsequent, much better, measures of inbreeding from marker data have been developed, and I now consider mean d2 as an idea that didn’t quite work. In retrospect, I should have realized issues with the measure when I wrote the papers, and should have devised a more useful metric. So I made a mistake, and am happy to admit it. But hopefully the science didn’t set the field back for more than a couple of minutes.
Inbreeding started featuring in my thoughts again recently (no, I haven’t married a cousin). I have just finished reading Will Provine’s book ‘The ‘Random Genetic Drift’ Fallacy”. In this book he argues that in simplifying population genetics down to a single, neutral locus on a chromosome, Fisher set population genetics on the wrong course. Fisher’s motivation for working with a single locus was to use developments in statistical physics to understand evolution, and some sort of simplification like this was, and still is, absolutely necessary. However, Provine argues that ignoring chromosomes and recombination led to Fisher – and nearly every population geneticist afterwards, including Wright – to confuse random genetic drift and inbreeding. If Provine is right, population genetics theory needs a major overhaul. And a consequence of that might be to revisit Wright’s shifting balance theory that has fallen from favour in recent years. If Provine is right, that really would be a paradigm shift in our field. But I’d be somewhat surprised – I still have a lot of respect for Fisher’s science.
So what happened to my colleague and her protagonist? It turned out she was right. She rose through the ranks, and is now a highly respected epidemiologist. Her meteoritic rise had nothing to do with the spat that she now chuckles about. But her protagonist remained bitter about the whole debacle and didn’t experience the successes my colleague did. For many years he apparently felt that she undermined his greatest scientific achievement, and that this prevented him achieving his true potential. Fortunately time is a great healer and I hear that he rarely mentions her name in anger now. And I suspect no one cares: certainly I can no longer remember what the issue was they were arguing over.
Senior Editor, Journal of Animal Ecology
* the urge to mention the government and badger culls is just too strong