Plant balances sex ratio, according to a report in New Scientist, 10 January 2004, p16. A South American herb named Begonia gracilis uses the amount of pollen it receives to determine the number of male flowers nearby. If it perceives an abundance of males it produces more female flowers. Scientists at the Independent National University of New Mexico gave plants varying amounts of pollen and found that plants given extra pollen produced 20 percent more female flowers than those receiving low or medium amounts of pollen. Many animals and birds are known to manipulate the sex ratio of their offspring. This is the first plant found to do this. Results were originally published in the Journal of Evolutionary Biology, vol 16, p1177.
Editorial Comment In spite of the fact this study was published in a journal devoted to evolution, the behaviour of this plant provides no evidence for evolution. There is a growing trend to label all biological processes “evolution,” especially those involved in reproduction. However, most processes described as evolution are really just descriptions of how animals and plants behave as a result of their pre-programed DNA code. Such behaviour is evidence of thought design. (Ref. plant, reproduction, evolution)