Discover nature’s powerful clocks
There is much that we can learn from the mind of a simple fruit fly, and research on the tiny creatures has already facilitated progress in our understanding of the biological, internal clocks that govern so much of our lives, said Michael Rosbash, a keynote speaker for the TWAS 16th General Conference on 21 November.
Michael Rosbash is a neuroscientist and chronobiologist at Brandeis University in the United States, and in 2017 was among the winners of the Nobel Prize in Physiology or Medicine for discoveries of molecular mechanisms that control circadian rhythms. Circadian rhythms are the ways that biological organisms align their lives with 24-hour cycles from day to night, governing important processes such as sleep.
The word “circadian” comes from the Latin phrasing, “circa dies”, which means “about a day.” The rotation of the Earth is such a powerful environmental force that circadian rhythms have risen independently in evolution multiple times, in bacteria, in plants, and again in animals. This is because of the evolutionary advantage it provides, or, as Rosbash put it: “The early bird gets the worm, and the early worm also avoids getting eaten by the bird.” These biological clocks also help govern the internal coherency of a creature’s body, keeping processes separate that can’t happen simultaneously.
The reason that research on the circadian rhythms of fruit flies is important, is that the insects sleep much like humans do. And what scientists have learned about the circadian rhythms of fruit flies has turned out to reveal insights about human circadian rhythms, which then turned out to be important for human physiology. Our biological clocks regulate sleep-wake cycles, hormones, and even cancer.
“The big picture concept is that circadian rhythms are solved in the fly, and it turned out to be the same in mammals,” said Rosbash. “The concept that has not been solved is why do we sleep, and what is the function of sleep. If that problem can be solved in fruit flies, maybe that will also turn out to be insightful for human sleep.”
“And so that means other human health problems will be similarly impacted by research in basic science,” said Rosbash. “The point is you never know what is going to emerge from basic science research and how it’s going to impact human health.”
Basic science, he said in his keynote lecture, is driven by two factors: curiosity and doubt. He said people are familiar with curiosity, but doubt can be more elusive. And what it means to doubt, is that people shouldn’t believe something to be true simply because of history, tradition or authority. The real key, he explained, is the evidence; this is why he teaches his students that, when someone offers up a fact, they should always ask what the evidence is, and how they arrived at that conclusion.
“Scientists are no better than any other group of people. They’re not more ethical, and not more honest,” said Rosbash. “But arguably, our ecosystem—publications, vigorous debate—probably keeps science more honest than other areas of the modern world we inhabit.”
He also emphasised the importance of internationalism, pointing out that global threats such as pandemics and climate change do not respect national borders, and so science must stress across borders, too.
Illustrating this point, he detailed some recent research by a Chinese postdoctoral student in his lab, Dylan Ma, whose work is helping illustrate the rich diversity of timekeeping brain cells in the fruit fly’s brain. He said he has had 15 Chinese PhD students and postdoctoral researchers in his lab over the course of his career and he believes he owes them a great deal.
“(Internationalism) is important beyond science,” he said. “We learn from other cultures in human ways.”