Limits to animal timekeeping

[Danijel Gorupec]

Without looking at my watch and checking other clues, I am fairly incapable to keep the record of time accurately - I close my eyes, cover my ears and then try to guesstimate when one minute passes... I usually miss a lot, but probably not much more than an average human. I am not sure if this is a skill that can be learned?

 

But, maybe there are animals that are much better at this. Is there any reason why some animal could not have a really good innate timekeeping abilities (without looking at outside clues)? I would be kinda disappointed if evolution found no better solution - is timekeeping a useless trait or is this just a hard problem?

 

Is there any research how good are animals at 'internal' timekeeping? Is an accuracy of 5 minutes per day at all achievable for an organism?

 

 

(I was reading about homing pigeons and was thinking how useful it would be for a pigeon to have a good inside-head-clock so that it roughly knows the longitude... But I am not asking about pigeons.)

[Delta1212]

Well, the question is really whether such precise time-keeping in the absence of external cues is all that useful for most animals.

 

 

How often does anything really need to know that 5 minutes have passed to within a second with no external input?

[swansont]

By and large our timekeeping "needs" are driven by artificial social constraints, rather than evolutionary ones. What animals need to be at work on time, or anything like that? What timekeeping is required, especially without visual cues?

[Danijel Gorupec]

Hmm.. except to assist navigation during migrations, which would probably require keeping time for week(s) within one hour, I must admit that I can't really point out some obvious advantage.

 

However, I have a vague feeling that having 'absolute' sense of time is just better than not having it - an animal could better synchronize with others in the pack and thus better use its own time (less checking outs:... my pack leader 'commanded' 1 hour resting time, so I sleep for one hour and wake up just on time... that female was fertile exactly 48.3 days ago, so I don't need to bother sniffing her but because 'it' is not going to happen).

 

So the actual question, IMO, is: is it so 'expensive' to have a clock? Why?

[Delta1212]

Evolution doesn't really care what's "better" though, only what is advantageous. If it doesn't confer a reproductive advantage, it's not going to evolve except by pure random chance, and the chances of randomly evolving a mechanism for keeping track of time at a finely granular level add very, very low.

 

Everything costs something, even if the cost isn't very high. If you're not using it for anything, there's no reason to have it, better or not.

 

Evolution works a bit like a NASA mission in that regard. Yes, there are plenty of things that it might be "better" to have onboard than not, but even small things ultimately do at to the weight, and therefore the fuel requirements and ultimately the expense. If you can't justify why it's getting shot into space other than "why not?" it's not going into space, and, especially for complex mechanisms like a hyper-fine time-sense, if there's no use for it, it's not going to happen.

[Danijel Gorupec]

Was thinking a bit... Accurate clocks did not exist in human society for long time. But once we got them into our possession, we quickly adopted them and are now using them extensively. I have no doubt that this is because clocks proved useful to us - to synchronize us and thus make our time and energy usage more efficient. Therefore, I see Swansont's claim that our timekeeping needs are result of artificial social constrains only as a part of the whole truth. Timekeeping truly can be innately beneficial to social animals and might be essential to create very complex (global) society.

 

One might argue that humans are exceptions and that other social animals could never benefit from accurate timekeeping because, say, their brain power is limited. I agree, but I think that a social animal would still benefit to some small degree. Taking in account that only miniscule amount of energy is needed to run an accurate clock (increase in clock accuracy does not require proportional increase in energy usage) I must conclude that energy expenses is not the reason to not have this feature.

 

As Delta1212 mentioned, it is the unlikelihood of the "pure random chance" of creating a clock that I see as the main reason for animals not having accurate timekeeping mechanisms. As I understand, a clock is complex and if just one part is removed, it becomes useless. It therefore cannot be created in a simple-step-by-simple-step manner where every further steps is increasingly beneficial to the animal... This reminds me to the "flagellar motor" controversy that was popular some years ago, if I understood the controversy correctly.

 

Flagellar motors exist... and this makes me wonder does accurate time keeping also exists. I noticed that we always suppose that there is no such thing, but I am not aware of any research on this topic. Of course I expect that some animals will be much better timekeepers than humans are - this would be not surprise. But I am thinking are there animals that are several orders of magnitude better timekeepers.... Ok, now I am heading toward speculation.

 

Still, an experimental research on the topic might be a valid idea (if not done already).

[John Cuthber]

I see the cows lined up in the field waiting for the farmer to come and take them for milking.

I guess that's an accuracy of about 15 to 30 minutes a day.

[Acme]

Biological clocks

...

The physiological mechanism which directs internal clocks is unknown.

...

II. DO ENDOGENOUS CLOCKS REALLY EXIST?

 

For years after the discovery of zeitgebers*, some argued that there is really no such thing as a truly endogenous biological clock; that all apparently endogenous rhythms are in fact exogenous, resulting from zeitgebers that are too subtle for us to detect.

 

But two lines of evidence, one of which we have already discussed briefly, strongly suggest the existence of endogenous clocks:

 

1) Individuals under similar conditions exhibit slightly different, but consistent rhythms, suggesting they are not being entrained by the same cue; in some cases these different rhythms are known to be heritable.

 

2) Animals and cell cultures in orbit continue to show circadian rhythms.

 

A few years ago, cell cultures exhibiting a 24 hour growth rhythm were sent up on board the space shuttle. The cultures' internal clocks continued to keep 24 hour time in space, in spite of the fact that obvious cues were controlled and any conceivable hidden zeitgebers, such as fluctuations in cosmic ray intensity, were now cycling at the rate of the shuttle's orbit.

 

Take-home message is that organisms have endogenous clocks that are free-running in the absence of zeitgebers. When zeitgebers are present, however, they entrain the clocks or keep them in synchrony with environment. Why hasn't natural selection resulted in perfect endogenous clocks?

 

1. Variability allows for adjustment to new or cyclical conditions--when might this be important?

 

2. There may be biological constraints as to how precise clocks can be.

...

*Zeitgeber @Wiki

A zeitgeber is any external or environmental cue that entrains or synchronizes, an organism's biological rhythms to the Earth's 24-hour light/dark cycle and 12 month cycle.

[Endy0816]

Provided you have reasonably set rates of production/reduction of something you can keep track of time that way.

[Acme]

Provided you have reasonably set rates of production/reduction of something you can keep track of time that way.

For instance...?

[swansont]

Was thinking a bit... Accurate clocks did not exist in human society for long time.

 

The sun has existed for longer than humans have. The earth's rotation is only inaccurate relative to the best 20th century clocks

[Endy0816]

For instance...?

 

Less a for instance and more an observation of how an internal clock could work within range of what cells can manage.

 

You check the present quantity of what you've been producing and that will be equivalent to the amount of time that has passed.

[Acme]

Less a for instance and more an observation of how an internal clock could work within range of what cells can manage.

 

You check the present quantity of what you've been producing and that will be equivalent to the amount of time that has passed.

That's pretty much circular though. I was hoping you had something more concrete. No worries; as I cited above, the biological clock mechanism remains unknown even by the experts. Time will tell?

[Danijel Gorupec]

Thanks Acme for your 'biological clock' article find. Nice examples... The question "why hasn't natural selection resulted in perfect endogenous clock" is just the question I was asking (because higher accuracy does not mean higher energy 'expenses')... The article doesn't mention, though, if there are some experimental research on limits how accurate these clocks might be.

 

(Speculations: There might be several different types of 'clockwork mechanisms' developed by natural selection that have very different accuracies. Also, animals might have very different level of awareness of such clocking. For example, a pigeon might have almost perfect clock in its head and use it to accurately determine longitude. And while it might be aware of the longitude, it might still be unable to access the time directly.)

 

@John Cuthber... One should be careful to exclude immediate external cues - cows might just be observant about sun position or human activity around. But if genuine, and if last time-sync event was, say, the sunrise, then the precision of 15-30 minutes after, say, 5 hours would be much better than I would expect from a human. (I always suspected cows might be supreme beings, lol).

 

There is a counter-example in city of Zagreb (Croatia) where, by tradition, a cannon is fired every day exactly at noon. This always surprises pigeons on the city square. Either these pigeons cannot predict the noon precisely, or have no control over their reaction. (And this clearly disqualifies pigeons as supreme beings )

 

@Swansont... You are right, humans (and all the life) have this perfect clock. Still, it seems that humans benefit from artificial higher-resolution clocks, so I suspects other social animals might also benefit from the same.

[Delta1212]

If I set my alarm to the same time every day for a week, I will start very consistently waking up a few minutes before the alarm.

 

That's precision within five minutes with the last "sync" being five to eight hours earlier (I pretty consistently get up before dawn), and I do it in my sleep.

 

There's more to time sense than being able to consciously mark off the exact moment that 5 minutes has passed.

 

It's like how I can tap my finger an arbitrary number of times on a table, and then repeat the action with the exact same number of taps even if I have no idea what that number actually is.

 

You seem to be looking for a fully conscious time-sense, but most things it gets used for in the natural world don't really require that much conscious input.

[swansont]

 

@Swansont... You are right, humans (and all the life) have this perfect clock. Still, it seems that humans benefit from artificial higher-resolution clocks, so I suspects other social animals might also benefit from the same.

 

Unless they are working or conducting some other form of commerce, I can't think of what the benefit might be.

[Roamer]

is this discussion still about whether/which animals have better time-keeping then us(hint:without clocks/intelligence there would be plenty)

 

That's pretty much circular though. I was hoping you had something more concrete. No worries; as I cited above, the biological clock mechanism remains unknown even by the experts. Time will tell?

 

Most things in life are circular.

[Danijel Gorupec]

You seem to be looking for a fully conscious time-sense, but most things it gets used for in the natural world don't really require that much conscious input.

Yes, you are right - probably most biological clocks are disconnected from higher brain functions. If this is also the case with humans (as you suggest) then it is a shame - I spent hours of my life sitting in my car at the same intersection, looking at the traffic light (not to miss it when it goes green) instead of watching girls passing by.

 

I also noticed the fact that I can wake up just a minute before my alarm clock turns on. This accuracy is so high that I find it hard to believe it is a result of an internal body timekeeping. I suspect it might be by some external cues. But if yes, if such precision clock exists somewhere in my body, then really is the shame that it is not accessible to my consciousness.

 

 

@Roamer... sure. But imo, the question is not so much if there are better timekeepers, but are there seriously better timekeepers (2-3 orders of magnitude or more) suggesting a different clockwork mechanism. If there are none, why not - because a precise clock does not need more energy than a lousy clock.

[Roamer]

 

 

but are there seriously better timekeepers (2-3 orders of magnitude or more

Well, you could look at insects and other small creatures;

some have a lifespan of a day or less, so IF they have an internal clock, it 'd be quite accurate.