Arkansawyer

Yes. RoundUp is just like antibiotics.

Soon RU will be used sparingly. Just like TB strains/staff are
resistant to antibiotics, Johnson grass, cocklebur,
pigweed will be coming back.

As well as some virulent cornworms and boll weevils.

Wired Magazine ran an article in their November 2004 issue about the appearance of a coca plant in Colombia that showed resistance to glyphosate (the RoundUp pesticide):

http://www.wired.com/wired/archive/12.11/columbia.html

The U.S./Colombia authorities have never publicly acknowledged its existence, but according to the article, all the growers in Colombia have switched to "Boliviana negra" -- the "Roundup-Ready" coca. Apparently, the original plant was discovered in a sprayed field, and cuttings were made from it, and were grown out like crazy. Seems it was a naturally-occurring mutation -- no signs of genetic manipulation. So much for Plan Colombia...

planned obsolescence by evolution.