
Plants do sums to get through the night, researchers show - llambda
http://m.phys.org/news/2013-06-sums-night.html
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jbri
It would seem to me that no explicit arithmetic is being done - it's simply a
consequence of natural behaviour.

Consider the case of a starch channel, the size of which is governed by two
factors - the quantity of stored starch, and the time since nightfall. (Other
factors may also affect the size, but are irrelevant to this discussion). This
seems like a construct that could quite feasibly appear in a plant. No
arithmetic is being performed by the plant, but simply these two factors
working in concert cause the rate of starch consumption to appear to be based
on whatever the starch level was when night fell.

The fact that the observed rate of consumption is such that nearly all the
starch is consumed by morning is easily explained by natural selection -
plants that consume starch too fast obviously starve overnight, while plants
that consume it too sparingly are using their resources inefficiently and so
would tend to be out-competed by plants that make better use of them. Over
many generations, the base rate of consumption would become tuned to how long
nights last in that region.

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seanalltogether
> Over many generations, the base rate of consumption would become tuned to
> how long nights last in that region.

From the article - "the starch store lasts until dawn even if the night comes
unexpectedly early or the size of the starch store varies."

The point is that the plants can handle 2 changing variables

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jbri
Night coming unexpectedly early is just one thing that could cause the amount
of starch stored to vary.

There's only factor changing here.

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personalcompute
Sensationalist title. You could also argue that physics performs sophisticated
calculus every moment to determine exactly where it should place your moving
vehicle.

Math was created to model the world - it does not create the world itself.

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rosser
The difference is that this seems more _predictive_ than merely _descriptive_.
A more apt analogy might be a car that calculates the rate at which it must
consume fuel in order to arrive at the next service station just as its tank
empties.

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apalmer
is this not basic metabolism regulation? really dont know kind of always
assumed this just worked in living things

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anigbrowl
If it was that simple you'd never be hungry or feel too full.

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esolyt
Non-mobile page: [http://phys.org/news/2013-06-sums-
night.html](http://phys.org/news/2013-06-sums-night.html)

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gaius
As my friend Bazza said when he read this, in the same sense that the number
of sheep in a field is determined by the field doing addition and subtraction.

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learc83
No, it would be like the field forcing sheep to leave at a constant rate
during the night so that it was very close to empty by (but not before)
morning.

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stiff
I would love to read a review of this article by the good old Djikstra...

