““It is also worth considering how time can be related to the soul; and why time is thought to be in everything” -Aristotle, Physics (330 BCE)

”...one may be inclined to state that researchers are actually clueless concerning the question of how the brain processes time.” -Marc Wittmann, The inner sense of time, Nature Reviews Neuroscience (2013)

”What, then, is time? If no one asks me, I know what it is. If I wish to explain it to him who asks me, I do not know.” -Augustine of Hippo, Confessions (400 AD)”

Everything happens in time, but only a few reliable processes (e.g. the rotation of the earth or the transition between the two hyperfine levels of the ground state of cesium 133) have been selected by society as the timers that organize civilization. Timing mechanisms would seem to be useful for the nervous system, but none have been identified (aside from circadian timing) and their potential existence is often doubted. We show that the quick onset and slow decay of CaMKII’s kinase activity is used by the male fly to know when he’s been mating long enough to transfer sperm to the female. Are flies the only animals that use this ubiquitous and highly conserved enzyme to organize their behavior? A quick review of the history of discoveries in Drosophila suggests not.

Here’s a story about the paper from Harvard.