A Gene That Makes You Need Less Sleep? | Hacker News Reader

A Gene That Makes You Need Less Sleep?

newyorker.com

47 pointsdanso14 comments

"Of course, as Pack himself is quick to point out, even combined with Fu’s data the mutation sample remains miniscule. So now, in an international collaboration with existing sleep-study cohorts spanning the U.K., South Korea, and China, Pack is in the process of gaining access to somewhere between half a million and a million participants. The next step is to sequence the twenty or so CLOCK genes (the genes that are involved in regulating circadian rhythms) that have been identified, to look for both the mutations Fu and Pack have found and any new variants that may affect sleep physiology."

Prediction: like all other human behavioral traits, sleep length will turn out to be influenced by multiple genes, each with small effect. That is the consistent finding of all human behavior genetics research in the genome-wide-association-study era.[1]

[1] http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3778125/

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3498585/

http://www.pnas.org/content/early/2014/01/16/1322563111

> Prediction: like all other human behavioral traits, sleep length will turn out to be influenced by multiple genes, each with small effect. That is the consistent finding of all human behavior genetics research in the genome-wide-association-study era.

You are 100% correct. I cannot think of a single behavioral attribute that has any correlation with only a single gene. Physical traits and diseases, absolutely, many are associated with just a single gene.

However! Your comment comes across to me like because it won't be just a single gene what's the point? Well because science is an incredibly iterative process and finding the first gene then leads to the second, and the third, and so on. As such, patience is a virtue for unlocking these complex puzzles.

Regardless, the way most science is reported by the media - even sources who ought to now better - is insulting to science as a whole.

You're right re: large numbers of small-effect variants - and it's also true for other genetically determined traits (such as cholesterol levels). Now, there are some high-impact, low-frequency variants in the non-behavioral sciences, but so long as they work additively (and generally are not recessive traits) they usually get picked up in the GWAS anyway.

Obliquely, this leads me to argue that you may well find great drug targets among the behavioral genetics GWAS hits (for certain traits).

I wonder what are the drawback for such a gene since I would think the evolutionary pressure for it should be pretty strong. Or maybe there wasn't really much to be done at certain times and resting was the best strategy some 10000's of years ago.

It wouldn't surprise me at all - sleep preserves energy, does it not? And since food has been a scarce resource for the majority of human history, there must have been a pressure to sleep longer to preserve energy on one hand, and shorter to have waking time available to find more food (and do other things that ensure survival and reproduction).

One proposed reason for the evolution of sleep is facilitating neural plasticity (growth and change). These studies merely show benefits in the short-term. An interesting hypothesis to test is if people with this mutation, over the long-term, have the same cognitive skills as those without, assuming both parties get the amount sleep they naturally need.

I imagine this is it. What would you do at night if there wasn't technology enabling you to keep yourself preoccupied? The list of things we can do takes a pretty big hit when we can't see well.

> What would you do at night if there wasn't technology enabling you to keep yourself preoccupied?

I can't imagine boredom to be a major evolutionary force back in the day.

There's lots you can do in the dark. And the night isn't all dark, either. There's the moon and stars. We have other senses, too. Just keeping watch and defending against lions seems like a good use of time already.

"If this was such a beneficial mutation, why isn’t it more common?"

Based on natural selection it would only necessarily be more common if it affected reproduction. It may begin to affect reproduction now that people are sleeping less and those that don't cope well (like those that don't have the gene) may die before they reproduce; but until recently when sleep deprivation has become a larger issue, I doubt it ever affected reproduction enough for natural selection to do its job.

I think if people who need to sleep more is at a competitive disadvantage compared to other people, they will be less able to provide for the next generation, which will allow natural selection to slowly weed out those who don't have the gene.

I do know a startup CEO with this exact condition. The guy is wicked smart and a lot is in his capacity on not needing sleep. I wish sometimes I could get by 4 hours and feel near-to-normal. Instead I live with approx 5 1/2 a day, plenty of caffeine and I struggle.

Why shold I sleep less?

Golly, there's a gene for everything!

One of my relatives has been sleeping on average 5-6 hours a day for past 10-15 years. She would sleep 3-4 hours a night with short naps during the day and then would have have a full 7-9 night sleep every few days. No health problems, absolutely functional person. Though she is still majorily concerned about her "lack of sleep" and thinks it's something that needs to be "fixed".

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