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' sciencenews.orgbob9.aspOpen ↗
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.
Posted by Robert Karl Stonjek.