Warm-Blooded Plants?
OK, there's no blood, but they do make their own heat
Susan Milius

"The dead-horse arum of Corsica looks and smells like the south end of a
horse that died going north," says Roger Seymour. He's actually talking
about a plant, and a more prosaic soul might add that it belongs to the same
family as calla lilies and jack-in-the-pulpits. Seymour is a zoologist, and
the plants he studies show an animalistic feature: They can generate body
heat. Most plants, including calla lilies and jack-in-the-pulpits, simply
assume the ambient temperature because their metabolic reactions hum along
so gently that they don't give off bursts of heat. The dead-horse arum,
however, belongs to the group of several-hundred plant species scattered
among some 10 families that can rev up their own furnaces. That heat can
launch strong odors, like those of a dumpster in August. In winter, warm
flowers can melt snow.

The dead-horse arum outdoes all the others, says Seymour, who's at the
University of Adelaide in Australia. The plant's flesh-pink blooms produce
more heat than does any other known plant or any animal considered in its
entirety. Scientists have measured higher rates of bodily heat production
only in the flight muscles of some insects and, possibly, the brown fat of
hamsters.

Descriptions of remarkable heat-making plant species date back more than 200
years, but scientists are still discovering new facets of the phenomenon,
sometimes hidden in plain sight. Current research about the biochemistry
behind plant heat may someday change the way people deal with heat. The
pattern of heating power in the botanical family tree intrigues
evolutionists searching for traits of ancient flowering plants. And, this
winter, two research teams have presented new research on what good this
heating does for a plant.

Read the rest at 'Science News'
http://www.sciencenews.org/20031213/bob9.asp

Worried to Death: Lifelong inhibitions hasten rodents' deaths
Bruce Bower

Some animals shy away from novel settings all their lives, preferring the
predictability of familiar surroundings. Although this can be a safe
strategy in the short run, it may have a fatal drawback down the line.

A new study finds that novelty-averse laboratory rats, after reaching
maturity, died at markedly younger ages than did their more adventurous
comrades. Heightened hormone responses to mildly stressful events throughout
life ultimately undermined the capacity of the inhibited rats to resist
tumors and other health threats, contend Sonia A. Cavigelli and Martha K.
McClintock, both psychologists at the University of Chicago.

In essence, stress responses cause the inhibited rats to age prematurely,
the researchers conclude in an upcoming Proceedings of the National Academy
of Sciences. These animals exhibit a 20 percent reduction in maximum life
span compared with that of their bolder brethren.

http://www.sciencenews.org/20031213/fob5.asp

Posted by
Robert Karl Stonjek.
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