It’s not just scientists that get old. Scientific fields have their own lifetimes, just like people.

Stage 1: Gestation and childhood
Arguably the most mysterious of all the life stages of a scientific field, and just as with mammals, a lot of it takes place out of sight. At this point there isn’t a field, or at least, it’s not recognised as such. There are disparate experiments that may not be obviously connected, quite possibly being conducted in different organisms and by labs in different parts of the world. There will be methodological development, but a field’s true birth may need to wait until the right technology comes along (just as the advent of next-generation sequencing ushered in modern epigenetics). These early observations may point to something significant, but broader recognition generally takes a while. 

Regrettably, and unlike human development, the gestation of fields tends to be poorly-documented, and foundational contributions can easily be overlooked when the field achieves later prominence. One notable exception is the area of CRISPR/Cas9-mediated virus defence, whose gestation was documented in unusual depth owing to the ongoing patent dispute over CRISPR genome editing.  The early observations of interspersed repeat units long preceded the realisation that it was a means of bacterial defence against viruses, and that realisation itself preceded the reconfiguration of CRISPR-Cas9 into a genome editing tool.

The scientists involved in this period will be eclectic – a mix of pioneers interested in esoteric areas of research, who may not even see themselves as a community as such and will not necessarily be in contact with one another. The field will not yet have coalesced around a set of consensus questions that will be tackled in a future research agenda.

Towards the end of the gestation and childhood period might come difficult teenage years – by now there will be an acknowledged community of labs working in the field, but  possibly also disputes between results obtained in different model organisms and problems of conflicting data.

 

Stage 2: Youth and prime
The field has now matured and is growing rapidly. There will be youthful enthusiasm aplenty, lots of new findings, and a general sense of heat and light being emitted. Big strides forward will be made in single publications, and conceptual and mechanistic breakthroughs will be common and deservedly recognised as such. The main theoretical models underpinning the field will now be defined, with the key questions and concomitant research avenues well-delineated. As in the teenage years, there might still be outstanding differences and rival camps cleaving to one model or another, but the lines separating these factions are now well-drawn (e.g. the factions supporting either cisternal maturation or vesicular transport as models of Golgi function). 

Reviews will begin to be written, the field will receive dedicated congress sessions and maybe even dedicated conferences in its own right. The field itself may be profiled in journal feature articles, the best work will get published in prestige journals (prestige journals may even be jostling to publish papers from the field at this time), and in time the field may even get its own dedicated journals. 

There will be a concerted effort to define links to human disease or some big societal problem, if such links do not already and automatically exist. Money will now be flowing into the field, and other scientists may begin switching or re-orientating their research programmes to try and get a piece of the action. By now there is an established community of scientists who know each other, with the relationships between them (whether collaborative or antagonistic) understood. The main figures will be early- and mid-career group leaders on a fast track to professorships, bullish and confident in their relevance. 

Stage 3: Middle-age, and maybe midlife crisis
When a field reaches middle age, there will be a sense that most of the big discoveries have already been made. A programme of consolidation will be underway, as the resolution and detail of its answers to its foundational questions continue to be refined (endocytosis research has arguably been at this stage for a while). 

Funding for research in the area remains relatively easy to come by, as the field is so established, but it is harder and harder to make significant contributions with that funding; this can result in unseemly squabbles over publications and status. The earlier influx of new researchers eager for a piece of the pie will have resulted in a squeeze at the community level, and the publication of papers may get increasingly rushed with knock-on effects on data quality and reproducibility. Key concepts may be misunderstood by dilettantes (the phase separation field appears to be at this stage right now), and the field’s founding custodians may struggle to maintain influence. 

There will be fragmentation into smaller sub-communities who are focused on increasingly small aspects of the field, and an overview of the area as a whole may begin to weaken as the volume of data makes it harder and harder to keep sight of the big picture. 

If the field has nonetheless been successful at keeping itself in the spotlight, its leading figures may now begin to win prizes and the field may even receive the ultimate accolade of a Nobel. Difficult midlife years can also lie ahead though, with retractions of some papers, and possibly also a sense that the field has not delivered on its early hype. By now, there will be fewer young scientists starting their own labs in the area. People begin migrating out of the field and into newer areas that are opening up.

Stage 4: Old age…and rebirth?
The field has now reached a comfortable old age. Its members are still active, but the research spotlight has moved on and work no longer gets published in prestige journals. There may even be a degree of crotchety old age, with bad-tempered arguments over small disagreements that have been going on forever (see again cisternal maturation and vesicular transport models of Golgi function, lipid rafts, and many more). The community has now reduced in size, and is mostly composed of lifers who’ve been there since they started their own labs. Some begin to retire. 

But in old age can also be the seeds of rebirth. New technology or new conceptual models can allow the field to get a fresh breath of life. Curious younger scientists revisiting the early days of the field may rediscover some of the old observations and questions that never got intensively pursued, and use these to start new research directions. Sometimes, a field may even be reincarnated with a new name – Synthetic biology might be a good candidate, emerging as it did from classical biochemistry and enzymology.

Obviously this sketch is focused on biology, but it probably applies more generally, and there’s a debt to Thomas Kuhn’s “The structure of scientific revolutions” which examines the same phenomena on a more serious and conceptual level. 

What stage do you think your scientific field is at?