Could ancient bacteria show us how to adapt to climate change in the near future?
Scientists at the John Innes Centre in Norwich are working with bacteria that appears to anticipate and adapt to the seasons. This quickly evolving organism could be used to predict how more complex organisms might adapt to rapid global changes in climate.
“Progress is made by young scientists who carry out experiments that old scientists said wouldn’t work – F. Westheimer” reads the quote on Prof Carl Johnson’s office at Vanderbilt University. Clearly a believer in the power of curiosity, Prof Johnson encouraged Dr Luísa Jabbur, his PhD student at the time, to run an experiment even though he was quite certain it would fail. That experiment led to a new discovery.
Image credit: Dr Luísa Jabbur
Dr Jabbur’s far-fetched idea was that an organism as simple and short-lived as cyanobacteria may be able to anticipate seasons. Although they don’t even have a proper nucleus, cyanobacteria have internal timekeepers, somewhat like the internal clocks which give humans our circadian rhythms. Amazingly, it seems that their timekeepers can work to anticipate seasons, driving the bacteria to make changes that will enable them to survive colder conditions, even if they have never experienced those conditions before. These bacteria appear to use their circadian clocks to measure day length and then pass on this information from one generation to another. If they experience enough short days, they modify their cell membranes to make them more fluid and prevent freezing when temperatures drop.
It has long been known that complex organisms respond to the change in seasons by detecting changes in day length – this phenomenon is called photoperiodism. Photoperiodism is widespread, from plants that time their flowering to maximise pollination, to mammals that time reproduction to ensure new-borns emerge into an optimal environment. Photoperiodism is an ancient, intelligent response that synchronises organisms living in an ecosystem and aids survival. However, it relies on the assumption that what has come before will come again. A growingly erroneous assumption in an era of unprecedentedly quick climate change. There is no doubt at this point that many species will not adapt quickly enough- entire ecosystems are already in disarray. Now, humans find themselves in the unsettling situation of not knowing exactly what will happen next: Will organisms adapt to climate change in time? How will they do this? Is there anything we can do to reduce the already catastrophic loss of biodiversity?
Unfortunately, artificial intelligence models are not so sophisticated yet as to be able to tell us how organisms might evolve in response to climate change. Bacteria might be though. By exposing cyanobacteria to varying climate conditions, Dr Jabbur may soon be able to see how cyanobacteria (and, arguably, more complex organisms) could adapt their photoperiodism to climate change. The results—potentially prescient. Extensive work goes into making the future a little more predictable, but perhaps the more is known, the more can be done.
Jabbur has also written a beautiful and illuminating review on the past, present and future of biological clock evolution.
Lorena Rosen, edited by Luísa Jabbur
21 November 2024