For much of the world, avoiding starvation is the principle goal, so for these areas, higher crop yields are beneficial despite lower nutrient density.
As Slicher Bath remarks in his book about the agricultural history of Western Europe, "Starving people do not eat less. On the contrary." They eat anything they can. It is the nutritional value that is the problem.
Actually, some of it just might be going on.
First, "Genetics" is a bit of an undefined term. There are Genes, which code for actions (in fact proteins to be made which perform actions), and transcription factors which guide when these genes are read and therefore activated.
For example, polar bears might make more stress hormones due to the heat, which might activate some genes which would otherwise not be active.
Apart from that, re-shuffling DNA does occur in some cases. In humans, this is one of the things that enable the immune system to react to new hazardous substances.
If you are interested, Professor Robert Sapolsky has a great introduction to genetics (part 4 and 5) as part of his college in behavioural biology.
It appears that PL/I (and its dialects) is, or will be, the most widely used higher level language for systems programming. -- J. Sammet