Friday, October 28, 2005

Biological Warfare in the plant kingdom.

Did you know that some trees actively use biological and chemical warfare agents against other plants in the area to prevent competition? A recent article on the ABC news website tells how the beautiful colors that leaves turn in the Fall are part of a mechanism that trees use to actively discourage the growth of other plants near them.

It is lucky they are inanimate objects or they might be sending inspection teams to each others groves to ensure that there are no WPD (weapons of plant destruction) being stockpiled. Perhaps they would hire birds to do aerial reconnaissance or bombing to destroy production centers.

In human societies and government conspiracies it is always follow the money, in biology and nature and the rest of the universe it is follow the energy. This tenet, that living things do not waste energy and that everything is done for some sort of advantage demanded an explanation for why a tree would use energy to manufacture a red pigment in the Fall that didn't seem to be made at any other time of the year. Researchers to realized that the red color wasn't just because the green chlorophyll was gone and letting other colors shine through, but that the compound was a defense against other plants in the area and would be released into the soil as the falling leaves decomposed.

The application of good old thermodynamics to the issues of biology are highlighting the fact that we might not have a full grasp of business as usual in the plant kingdom. There ain't no such thing as a free lunch and the evolutionary pressure on organisms means that plants are producing these compounds because they derive some advantage from them, the pretty colors are our fringe benefit.

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