He replied, “Close to zero to put it precisely.”

“Researchers had planted thirty-one thousand petunia plants during the field trial, which was carried out during the summer of 1990. The petunias were naturally white, but researchers had inserted a foreign gene which they expected to turn almost all the plants brick red. The plants grew and produced the anticipated red flowers, although some of the flowers, as they grew older, tended to fade in color. Then, after a midsummer heat wave, practically all the flowers turned shockingly white, and later in the summer the plants produced a mixture of red and white flowers. None of these results had been anticipated. Further research showed that heat had chemically disrupted the structure of the 35S promoter, which controlled the inserted gene. The white petunias became a powerful image illustrating the gaping holes in science’s understanding of genetic processes within plants.”

“A vicious cycle exists between physical inactivity and muscle strength. Weaker and smaller skeletal muscles with aging engender reduced physical activity, the diminished physical activity further decreases the size of skeletal muscle, and the downward spiral continues.”