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Scientists Describe Internal Clocks That Don't Follow Day and Night Cycles

Posted by samzenpus on from the up-all-night dept.

sciencehabit writes "Almost all organisms, from bacteria to mammals, have a circadian clock—a mechanism in their cells which keeps them in sync with Earth's day-and-night cycle. But many organisms follow other rhythms as well. Now, new research provides the first evidence that animals have molecular cycles independent of the circadian rhythm. They include a sea louse whose swimming patterns sync up with the tides, and a marine worm that matures and spawns in concert with the phases of the moon. The discoveries suggest that noncircadian clocks might be common and could explain a variety of biological rhythms."

23 of 91 comments (clear)

  1. Lunar clocks? by ozmanjusri · · Score: 5, Interesting

    I wonder if they realise a significant proportion of humanity have internal clocks based on a lunar cycle?

    --
    "I've got more toys than Teruhisa Kitahara."
    1. Re:Lunar clocks? by Narcocide · · Score: 5, Funny

      My internal clock is based on a caffeine cycle.

    2. Re:Lunar clocks? by Maxo-Texas · · Score: 2

      After I retired, it became clear my "natural" cycle was about 26 hours.

      Annoying!

      --
      She was like chocolate when she drank... semi-sweet at first and then increasingly bitter.
    3. Re:Lunar clocks? by Anonymous Coward · · Score: 2, Interesting

      Well, "lunacy" is definitely a thing. People freaking out during full moons has happened since the dawn of man.

    4. Re:Lunar clocks? by jdbuz · · Score: 2

      Nope. Well, not unless you're really into surfing. But all that nonsense about hospital rooms visits and the like syncing with lunar cycles has been debunked time and time again. For example: Bad Astronomy Science Daily

    5. Re:Lunar clocks? by captainpanic · · Score: 3, Informative

      I think that the female cycle is close to the lunar cycle, but not exactly synchronized with it. It would be similar to people having a 22 hour day cycle instead of 24.

      The menstrual cycle can be anywhere from 25-35 days, with an average of 28 days.
      The lunar cycle is 29.5 days.

      On a sidenote, imagine the horror if all women of the world would have their period exactly synchronized!

      http://en.wikipedia.org/wiki/Menstrual_cycle
      http://en.wikipedia.org/wiki/Lunar_phase#Overview

    6. Re:Lunar clocks? by lennier · · Score: 5, Funny

      Warewolfs

      If bitten you have an irresistable urge to download cracked pirate copies of the latest games? Or just want to hang around large empty buildings filled with shipping goods in transit?

      The wearwolf, now that's far a more dangerous beast; it haunts the catwalks of Paris and Milan, possessed of an insatiable hunger and a suit with more dimensions than the eye can follow without watering.

      --
      You are not a brain: http://books.google.com/books?id=2oV61CeDx-YC
    7. Re:Lunar clocks? by Anonymous Coward · · Score: 2, Interesting

      It's even more annoying whilst in the midst of your career like I am. I have noticed I definitely do not operate on a 24 hour clock either and it is hell. Fortunately for me I telecommute. A few weeks ago I was going to bed at 4pm while waking up around 2am, and day after day it kept getting progressively later until I made my way all around the clock again. For the past few days I've been taking two 4~ hour naps. One around 3pm and one around 3am.

    8. Re:Lunar clocks? by formfeed · · Score: 5, Funny

      You forgot about the wherewolf. The poor thing gets constantly lost.

    9. Re:Lunar clocks? by Thanshin · · Score: 2

      My manic/depressive system works on a weekly cycle. Except when I'm on holidays.

    10. Re:Lunar clocks? by Cryacin · · Score: 2

      There are many out there whose clocks are based upon how often windows needs a restart.

      --
      Science advances one funeral at a time- Max Planck
    11. Re:Lunar clocks? by gigaherz · · Score: 4, Interesting

      Sleeping after lunch works well for a lot of people. I'm Spanish -- we know about our 'siesta'.

      There's evidence that we naturally used to sleep in two phases, and some people have suggested a similar pattern to yours.

    12. Re:Lunar clocks? by epine · · Score: 2

      On a sidenote, imagine the horror if all women of the world would have their period exactly synchronized!

      From what I've been reading lately—in recent books—about half of the crabbiness is due to women not eating enough to compensate for their increased metabolic rate during their periods. Men also get crabby when we don't eat enough to replenish our willpower reserves. It takes willpower to make the generous response rather than the first lizard response that enters our brain.

    13. Re:Lunar clocks? by ozmanjusri · · Score: 3, Funny

      That could explain a lot about both Parkinson's and Tourette's...

      --
      "I've got more toys than Teruhisa Kitahara."
    14. Re:Lunar clocks? by TapeCutter · · Score: 4, Interesting

      A quick check of WP says that the largest meta-study found no correlation, they found what they claimed to be "statistical errors" in the 20 studies that did find a correlation. To me that doesn't say "no", it says the evidence we have to date is weak (unless there's a much larger set of "error free" papers backing the "no correlation" side).

      Personally I think there is a grain of truth in it, and my ex-wide who worked in ER for several years (as a cleaner) swears by it. However the moon doesn't actually create freaks from otherwise normal people, rather it provides just enough light for existing freaks to wander about at night and hurt themselves/others. I wouldn't expect the effect to be noticeable in a modern city hospital because city lights outshine the moon anyway. Weather also plays a huge role in the number of freaks wandering around at night, like everyone else, they (mostly) have enough sense to get out of the rain and are much more active on warm nights than cold. According to my ex-wife and her co-workers, a full moon on a hot and humid Saturday night is the perfect freak storm in a rural (or beachside) ER, statistically you're more likely to be murdered on a hot humid day than any other day.

      There's a very good reason that virtually every ancient religion has a sun and/or a moon god, they were observed to rule the natural cycles around them. Modern city/urban life obscures most of those observations and people are left wondering why the hell stone age people went to the effort of building places like stone henge.

      I think it's pretty much the same reason our modern society went to the effort of building the LHC or the Hubble telescope, ultimately they were trying to understand the world around them. Knowing where and when to turn up for an "all you can eat" buffet is a very deep behaviour in evolutionary terms, creatures as diverse as apes, jellyfish, corals, bears, and crocodiles make good use of it.

      In most cases we are at a complete loss when it comes to explaining these things in detail. For example, how do crocodiles "know" to gather an hour or so before fish become trapped on a flooded river ford? - The brief event (filmed by Attenborough) only happens right at the peak of a king tide. AFAIK, nobody (including Attenborough) has a clue how the hell the crocs tell the difference between a high tide and a king tide BEFORE it arrives. In ancient times people just accepted that (say) the crocs inexplicable ability to predict king tides was due to "divine knowledge".

      Humans are the undisputed masters of observing and exploiting patterns, however the root cause of the pattern is often irrelevant to it's utility. Ancient people would have simply observed the crocs (a wise defence behaviour anyway) and been alerted to the imminent fish bounty by their behaviour, some would have been mauled/taken by crocs when they went after the fish, lucky escape stories would abound, semi-random rituals would rapidly emerge to appease and thank the crocs. Next thing you know everybody wants a row of granite crocodile gods adorning their pyramid's driveway, and virgins are feeling nervous.

      --
      And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
    15. Re:Lunar clocks? by ciderbrew · · Score: 5, Funny

      I keep falling off my beer cycle.

  2. Isn't the natural period of human clocks 27 hrs? by tlhIngan · · Score: 2

    ISTR that the period of the human body clock is not 24 hours, but 27.

    That is, if you remove the cues of time from someone, their natural sleep/wake cycle would rapidly approach 27 hours.

    Something about it being based on a relaxation oscillator which means the day/night rotation of the earth actually resets it constantly...

  3. Re:Isn't the natural period of human clocks 27 hrs by jdbuz · · Score: 2

    Everyone's different. Some go longer some shorter. There's been a few deep studies on this but I think the most accessible description I've found is in the book Sync by Steven Strogatz

  4. Different for me... by fahrbot-bot · · Score: 4, Interesting

    My biological clock seems to run around a 26-30 hour cycle, which often makes it difficult for me to maintain "normal" work hours. Trying to go to sleep early is often fruitless so, eventually, I simply stay up all night and drag myself through the next day and then go to bed at an appropriate time to force reset my cycle. I've been this way for as long as I can remember - and I'm now 50. On the up side, I can (still) work productively for 36+ hours straight - I'm a senior mostly-Unix-ish system programmer/administrator btw.

    --
    It must have been something you assimilated. . . .
    1. Re:Different for me... by wonkey_monkey · · Score: 5, Funny

      and I'm now 50.

      On the plus side, that's only 43 in "you" years.

      --
      systemd is Roko's Basilisk.
    2. Re:Different for me... by 0111+1110 · · Score: 2

      You've had this non-24 condition since birth? That's tough. I can't imagine having that problem as a kid while in school. Damn. It only started for me after a head injury, but now my normal cycle is also around 25-27 hours. It does make it extremely difficult to lead a normal life.

      I assume you've tried everything, but have you tried Dark Therapy? No artificial lighting after dark? It's kind of tough for me because it means I can't use a computer or read. I've sometimes listened to audio books though and a really boring audio book can be helpful for putting you to sleep as well.

      There are some theories that it is only necessary to eliminate the shorter wavelengths of light and that amber to red light is okay, but I think this is false based on my own experience and based on mouse studies where you have to get above 700nm for circadian rhythms to be unaffected and it's pretty hard to see that near infrared and only LED lighting could be that precise. One of these days I do plan to buy some 710-740 nm LEDs and test out whether I can read with them and whether it helps the non-24.

      --
      Quite an experience to live in fear, isn't it? That's what it is to be a slave.
  5. The most important cycle of all by stox · · Score: 4, Funny

    The paycheck cycle.

    --
    "To those who are overly cautious, everything is impossible. "
  6. Re:Useful, but not the first to test it by lubaciousd · · Score: 2

    Check out Dr. Takahashi's work at UT-Austin; a good one behind a paywall is Temperature as a Universal Resetting Cue for Mammalian Circadian Oscillators. Among other things, his group has investigated a variety of timing-dependent tissues(liver cells, neurons, stomach cells) and whether or not temperature could serve as a temporal resetting cue(the answer in many cases is yes).