August 22, 2006 — By James Gorman, NYTimes
As humans age, so I’m told, they tend not to sleep as well as they once did. There are all sorts of reasons — aches and pains, worries about work, and lifelong accumulations of sins that pretty much rule out the sweet sleep of innocence.
But what about fruit flies?
Not as a cause of insomnia. What about the problems fruit flies have sleeping? Yes, Drosophila melanogaster also suffer sleep disruption when they get older. And a report on the troubled sleep of drosophila is being published in The Proceedings of the National Academy of Sciences.
This is the kind of science that makes you wonder. For instance, are the female flies suffering from hot flashes? Are the male flies getting up to go to the bathroom three or four times a night? Of course not. Fruit flies don’t have bathrooms.
Or you may wonder what troubles are keeping the flies up. They don’t have to worry about family values, illegal immigration or debt. They don’t have families or money.
And given the ubiquity of fruit and of scientific research, I’m guessing drosophila, bless their little genomes, must benefit from something close to full employment.
What I wonder is why people waste time worrying about whether we evolved from animals. But they do.
As reported over and over again, a disconcerting number of Americans doubt the fact of evolution. The country seems almost evenly divided on the matter, according to a recent report in Science. Some of the worriers concentrate on apelike ancestors, showing a lack of vision. There are stranger connections to agonize over, like drosophila and beyond. We share sleep problems with fruit flies. We have a huge amount of DNA in common with yeast.
Those are our distant cousins we consume in leavened bread, our fellow multicelled organisms undergoing dreadful experiments in the drosophila lab.
For instance, scientists have heated up the ambient temperature in fruit flies environments to see what happens. At 64 degrees Fahrenheit they live twice as long as at 84 degrees. Live hot, die young.
What does that mean for us? We really do share a lot with drosophila. As the article in the Proceedings reports, fruit flies have sleep-wake cycles that become fragmented as they age, suffering a “loss of sleep consolidation, namely increased daytime sleep and increased nighttime wakefulness in the elderly,” as Kyunghee Koh at the Howard Hughes Medical Institute and three colleagues describe it.
Sound familiar? It should. Some of the same genes related to circadian rhythms occur in humans and in flies. Mutations in some of these shared clock genes can cause sleep disorders in people.
We also share genes related to learning and alcohol sensitivity. But even these commonalities are not worth worrying about. The genes are just details. We have the same basic cell machinery — DNA, for example — with everything living. Broccoli rabe for instance, is known to have DNA. You may find it bitter, but you still share an evolutionary history with it.
The bacteria in my gut accounts for more genes than I have in my chromosomes. We not only have a lot in common with microbes, in a way that is only beginning to be understood, we are microbes.
This is fine with me. I’m delighted to be related to flies, yeast, frogs, chimps and blue-green algae. I find the serenity of algae restful and the ambition of yeast admirable. Frogs are great jumpers. Chimps have hands at the end of their feet, sort of. And fruit flies, well, I never met a fruit fly that I was ashamed to share genes with, and I certainly can’t say that about human beings.
Watch the news. Read history. Be honest, if you could pick your relatives, would you choose this species?
By the way, Dr. Koh and colleagues don’t have a cure for age-related sleep disturbance — in flies or people. But I, for one, will rest easier knowing I’m not the only one lying awake at night. My drosophila cousins are probably up too.
I wonder what flies count when they can’t sleep — paramecia?
No comments:
Post a Comment