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« As if winning a Nobel Prize wasn't enough... | Main | The Goal of Causal Inference »
23 January 2007
So it's finally getting cold in Boston after some days that resembled Spring more than anything. Outside the buildings, smokers in T-shirts and flip-flops? The first flowers blooming?? But it's not all lost: I was just reading that an early Spring or a short interval of warm temperatures doesn't really matter for plants and animals. Plants just grow new buds or skip a year. Animals adjust their sleep patterns. But maybe Mother Nature is also smart about predicting when it's the right time to wake up. Are plants and animals Bayesians and have learned to give more weight to a signal that is a better predictor of changes in seasons than temperature?
Apparently plans and animals have an internal clock that measures the length of day and night by using length of sunlight exposure as proxy. Having been around a couple of hundred years they might know that relying on the length of day is a safer bet than relying much temperature. I wonder whether there is evidence of Mother Nature changing those weights over time, as one of the signals becomes more reliable? Maybe temperature was a better predictor when the Little Ice Age began? It wouldn't be so great to wake up when it's well below zero in late May. This would be a good example for Amy's post on Bayesian inference and natural selection (see here).
Here in the computer lab of an unnamed basement in Cambridge, MA, yours faithful won't be fooled by the temperatures either. I'll take a nap now.
Posted by Sebastian Bauhoff at January 23, 2007 12:00 PM
"I was just reading that an early Spring or a short interval of warm temperatures doesn't really matter for plants and animals."
Do you have a link for that?
Posted by: son1 at January 23, 2007 12:34 PM
Some plants or seeds "react" after cumulative value for temperature exceeds certain threshold.
Length of the day is usually related to breeding season i.e. when the day shortens some wild animals mate so that the offspring will have enough food in late spring. This however is dependent on how far from equator animals live.
Posted by: Gregor Gorjanc at January 23, 2007 5:55 PM
Here the link to the article I read. Unfortunately it's in German and now costs 50 Euro-cents to download. Sorry for that, I imagine there might be English-language material somewhere. Let us know if you find anything.
http://service.spiegel.de/digas/servlet/find/DID=50186322
Thanks Gregor for your comments. So the cumulative temperature is another measure that nature can use. I'm curious about the relation of length of day and breeding behavior. It's been quite warm and is now getting cold -- does that mean the offspring might arrive before Spring really arrives?
Posted by: Sebastian Bauhoff at January 24, 2007 1:22 PM