Catching up after the holidays, I finally got around to reading Scott Gilbert‘s recently published essay in PloS Biology. In case you haven’t seen it yet, the essay proposes that developmental biology is ‘the stem cell of biological disciplines’, and that many other areas of biology – such as cell biology, genetics, immunology, oncology and neurobiology – all grew out of developmental biology (or embryology, as it was more commonly known back then). He also discusses why it is that our field isn’t as well regarded as it should be – why, in words from former SDB president Blanche Capel reproduced in the essay, “…developmental biology does not get the credit it deserves for its contributions to understanding the natural world”. I found Gilbert’s essay fascinating and illuminating, particularly in terms of learning more about how embryologists of the 19th and 20th centuries were instrumental in the birth or growth of so many fields. While many of us are familiar with the fact that Thomas Hunt Morgan, one of the founding fathers of modern genetics, was first an embryologist, and with Haeckel’s ideas of the parallels between ontogeny and phylogeny, the idea that – for example – immunology was born out of developmental biology was new to me.
Gilbert concludes his essay with three take-home messages. He makes the case for the continued importance of developmental biology as a ‘vital generative science’ that is entering ‘a new golden age’ as the field expands in new and fascinating directions (echoing Daniel St Johnston‘s essay ‘The renaissance of developmental biology‘, also published in PLoS Biology). And he argues that ‘many of the disciplines that had come from developmental biology are returning to a developmental framework’. Both these messages resonate strongly with me and, I’m sure, with many members of our community. But his first take-home message doesn’t seem quite so straightforward. Gilbert states that ‘…developmental biology is not a confined, specified discipline – such as genetics, cell biology, immunology, oncology, neurobiology and so forth’ and that ‘the descendants of developmental biology … are more differentiated and their potency much more restricted’. Now, I don’t like to challenge someone who’s promoting the importance of developmental biology (and of course I personally think it’s by far the most fascinating field of biology!), and I’ll admit to feeling somewhat uncomfortable questioning the conclusions of someone of Gilbert’s stature. But sitting in an office with the Journal of Cell Science team, I’ve always seen developmental biology as a more confined field than cell biology, and looking through the tables of contents of genetics journals, I generally feel that they span a broader area than Development. So I find this message somewhat counter-intuitive.
I largely agree with Gilbert that developmental biology is ‘not confined to any level of organization’ and ‘can be studied in any species, organ system, or biome’. And I would make the case that it goes beyond embryology, encompassing the fields of homeostasis, regeneration and ageing to span the entire life of an organism. But does this really make it ‘undifferentiated’ as Gilbert states? I won’t argue against the analogy between developmental biology and stem cells when it comes to its history of budding off new disciplines (I’m not a historian of science so I don’t have the knowledge either way!). But I do feel that he perhaps takes the analogy one step too far by saying that this makes the field ‘pluripotent’. Sure, developmental biology is a broad research area, with important interdisciplinary crossovers spanning biochemistry to behaviour, but it does have its limits – there are lots of questions in biology where the links to development are tenuous at best. And while I like the idea that developmental biology ‘regenerates itself constantly as new techniques and hypotheses become available’, I suspect you’d find many cell biologists, geneticists and others who would say the same about their fields. From my reading, Gilbert’s essay seems to be trying to make the claim that developmental biology is more creative than other fields, and I find this a little harder to swallow.
Gilbert’s essay has – quite rightly – received a fair bit of positive praise on social media, and I hope that it will help to raise the profile of developmental biology among the wider scientific community, educators and funders (in this context, I’m particularly taken by Gilbert’s Competing interests statement!). But I’m writing this post because I’m intrigued to know if my reservations chime with other readers, and to find out what other people think about this: does it really make sense to make the case for developmental biology as ‘the stem cell of biological disciplines’?
I’d love to hear your thoughts in the comments below!