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• 1 2021-04-25T16:21:30-07:00 The Chronobiology of Plants: A Note 7 The time-telling mimosa pudica plain 2021-04-25T19:01:28-07:00 This commentary on floral electric fields reminds me of another, seemingly magical property of plants: their ability to tell time. In 1972, a French astronomer by the name of Jean-Jacques d’Ortous de Mairan discovered that plants have internal clocks. The astronomer had noticed that the flowering mimosa pudica would expose its leaves during the day and tucks them away in the evening.
  
  He assumed the plant did this in response to light or a lack of light. To test the theory, he placed the mimosa in a cupboard for a number of days, checking it at different times (without letting any light into the cupboard) to observe his results. What he found was that, regardless of whether the plant was exposed to light, it would still open its leaves at the same time each day, and hide them at the same time each night. This suggested something extraordinary: that plants had their own way of telling time, independent of environmental stimuli, and this launched the field of chronobiology.
  
  Animals (human included) also possess an internal clock. In humans this is our circadian rhythm which uses chemicals in the brain to signal when it's time to sleep and when it's time to wake. The internal clocks of animals can also assist them in the beneficial timing of activities such as foraging, migration and reproduction.
  
  An understanding of time was once thought to be a human property—one of the things that separated us from animals, plants and non-living matter—but is turns out that the ability to tell time is woven into the DNA all living beings. 
  
  
  
  Further Reading
  • Society for Research on Biological Rhythms: The birth of chronobiology: a botanical observation: https://srbr.org/the-birth-of-chronobiology-a-botanical-observation/
  • Walker, Matthew. “Chapter 2: Caffeine, Jet Lag, and Melatonin: Losing and Gaining Control of Your Sleep Rhythm.” Why We Sleep, Penguin, 2017.
  • Kronfeld-Schor, Noga, et al. “Chronobiology of Interspecific Interactions in a Changing World.” Philosophical Transactions: Biological Sciences, vol. 372, no. 1734, 2017, pp. 1–13. JSTOR, www.jstor.org/stable/44679423.