You may have heard about that odd hothead mutation in Arabidopsis that seemed to be violating a few principles of basic genetics—there was an unexpectedly high frequency of revertants that suggested there might be a reservoir of conserved genetic information outside the genome. Reed Cartwright proposed an alternative explanation, that gamete selection could skew the results. Now the latest reports suggest that the bias was an artifact of foreign pollenization (which I think is interesting in itself. Life is damned good at sneaking its genes in wherever it can.)
Anyway, if that’s all gobbledygook to you, Scientific American has put up a lucid summary of the hothead affair. It’s an example of good science, where the observations and hypotheses are hammered out and refined to get a best explanation.