Was at the allotment the other day, and my son Frederick asked how the seeds we plant could ever survive when it took so much work and preparation to plant and support them. I said it was because they’ve been selected (by breeding) to produce high yield, and that tends to make them less robust (in comparison to e.g. weeds). So he asked why don’t we breed in robustness. I instinctively said that you can’t do that, because breeding involves selecting for a characteristic, whereas (I think) robustness implies performance under a range of different conditions, some of which will not even be known to us. Of course, I agree you can breed in resistance to a particular circumstance, but I think robustness is about resistance to many circumstances. I think a robust population will include wide variation in characteristics, whereas selection by breeding tends to refine the characteristics, reducing variation. My reply was instinctive, but I think it’s broadly speaking correct, although it would be nice to find some counter examples!