Re: [math-fun] Polynesian (Pacific Ocean) navigation pre-clocks, pre-GPS
Bees have an internal clock, and they also keep track of the sun. The combination gives them direction information adequate for their (short distance only) needs. I think some other animals track stars, but do not recall the details. (It would probably be long distance migrating birds or insects.) Some bacteria also have magnetic compasses, which they use to keep track of "up" versus "down." Question: How do plant seeds, when germinating deep, know which way is "up"?
Statocyte cells, at root tips and in vascular bundles, contain heavy statolith organelles, which fall to the bottom. The mechanism by which this causes directional growth isn't well understood, to my knowledge. On Thu, Mar 26, 2015 at 3:07 PM, Warren D Smith <warren.wds@gmail.com> wrote:
Bees have an internal clock, and they also keep track of the sun. The combination gives them direction information adequate for their (short distance only) needs.
I think some other animals track stars, but do not recall the details. (It would probably be long distance migrating birds or insects.)
Some bacteria also have magnetic compasses, which they use to keep track of "up" versus "down."
Question: How do plant seeds, when germinating deep, know which way is "up"?
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Warren D Smith