Let’s imagine a tiny micro-organism that lives in the soil. It has a short life-cycle, let’s say 1 week. So sometimes it’s born in the winter, and sometimes in the summer, and these different seasons call for different behaviors in various ways. In this situation…
I want to say, that bacteria:
have shorter lifecycles than that (like, less than a day)
and yet still have circadian rhythms, surprisingly
Prokaryotes were long thought to be incapable of expressing circadian (daily) rhythms. Research on nitrogen-fixing cyanobacteria in the 1980s squashed that dogma and showed that these bacteria could fulfill the criteria for circadian rhythmicity. Development of a luminescence reporter strain of Synechococcus elongatus PCC 7942 established a model system that ultimately led to the best characterized circadian clockwork at a molecular level. The conclusion of this chapter lists references to the seminal discoveries that have come from the study of cyanobacterial circadian clocks.
the genome encodes for (among other things) a “season sensor” that can trigger appropriate downstream behaviors.
So you can look into this and check for that. I’d expect a clock, which would switch things on and off. But, I don’t know how/if, say cyanobacteria do handle seasons. I’d first check circadian rhythms because that seems easier. (I want to say that day/night difference is stronger than season (and occurs everywhere) but it might depend on your location. Clearly stuff like polar extremes with month long ‘days’/‘nights’ might work differently. And the handling of day/night having to change around that being different, does seem like more of a reason for a sensor approach, though it’s not clear how much of a benefit that would add. I’d guess it’s still location dependent.)
I want to say, that bacteria:
have shorter lifecycles than that (like, less than a day)
and yet still have circadian rhythms, surprisingly
Searching ‘bacteria colony circadian rhythm’ turned up:
https://link.springer.com/chapter/10.1007/978-3-030-72158-9_1
abstract:
Okay, how long is the lifecycle of Cyanobacteria?
Searching ‘cyanobacteria lifespan’:
https://www.researchgate.net/post/What_is_the_average_life_span_of_Cyanobacteria
6-12 hours (depending on temperature).
So you can look into this and check for that. I’d expect a clock, which would switch things on and off. But, I don’t know how/if, say cyanobacteria do handle seasons. I’d first check circadian rhythms because that seems easier. (I want to say that day/night difference is stronger than season (and occurs everywhere) but it might depend on your location. Clearly stuff like polar extremes with month long ‘days’/‘nights’ might work differently. And the handling of day/night having to change around that being different, does seem like more of a reason for a sensor approach, though it’s not clear how much of a benefit that would add. I’d guess it’s still location dependent.)