Nikolai Vavilov Quotes

In the early 1900s, Soviet agronomist Nikolai Ivanovich Vavilov discovered a strange phenomenon: weeds in crop fields sometimes begin to look like the crop themselves. Original rye plants, he realized, looked nothing like the plump grain that by then was a staple crop in Russia. It was a scraggly, inedible weed. Rye, he realized, had performed an incredible trick of mimicry. Early wheat farmers, weeding by hand, pulled out and discarded the rye-weed to keep their planted crops healthy. So, to survive, a few rye plants took on a form more similar to wheat. Farmers still extricated the pesky rye, when they could spot it. This selective pressure molded the rye to evolve to trick a farmer’s discerning eye. In this case, only the best impressionists survived. Eventually, the rye became so excellent a mimic that it became a crop itself. “Vavilovian mimicry” is now a basic fact of agriculture.* Oats are a product of the same process; they also got their start mimicking wheat. In rice paddies, the weed known as barnyard grass is indistinguishable from the rice at the seedling stage. Recent genetic analysis found that this weed began to change its architecture to match the rice about a thousand years ago, when rice cultivation in Asia was well underway. In lentil fields, common vetch is a ubiquitous weed that masterfully redesigned its previously spherical seeds to be the same flat, round disc shape as lentils themselves. In that case, the plant needed not to trick a farmer’s eye but rather make itself impossible to eliminate from the mechanical threshing process. Winnowing machines simply could not tell the difference between a vetch and a lentil. Weed genomicist Scott McElroy argues that modern herbicide-resistant plants are actually just engaging in Vavilovian mimicry at the biochemical level; they are mimicking the crop plants that have been conveniently engineered to tolerate the herbicide.