IP And Genetics: Genetic Copyleft?

"Suddenly, the free exchange of plant resources is in question as discoveries representing millions of dollars in profits are patented, potentially keeping poor farmers from using them." uncadonna writes "Here's a story (NYT; free reg. req.) about genetic scientists who want to maintain natural genetic diversity in food crops, resorting to defensive patents. Sounds like kindred spirits to me. Wonder if they've ever heard of copyleft."