This study claims that the plants changed their genetic make-up in response to a warm-spell. This is exactly what doesn’t happen, and it smacks of Lamarckian genetics-changing-to-fit-environment thought that preceded Charles Darwin. Some plants happen to have a different genetic make-up that responds well to warmer weather, these would appear gradually over a long long period of time.

What Mr. Weis was observing was a plant that could behave in different ways, much like a human could don a coat, or not. Carry water in a container, or not. There is no genetic change here, simply a clarification of the versatility a mustard seed.