[jivatmanx]

A species, the lowest taxonomic classification on the tree of life, is defined by the ability to crossbreed. [0]

Previously, any crossbreeding between plants, by necessity had to belong to the same species. Since this is the lowest taxonomic classification, the vast majority of the genome was shared.

Now, a plant can be crossed with any other species on the tree of life. That's a significant difference.

[0]https://en.wikipedia.org/wiki/Species

[maxerickson]

All you need to say is that without modern methods of direct gene alteration (and perhaps mutagens), organisms had to be able to breed to have their genes crossed (fertile offspring make the cross more interesting). Talking about species just muddies it up.

Of course, GMOs can also pass the tests of successfully maturing and reproducing.