In a recent tweet, Bill Gates worried that the “world is facing a crisis at the dinner table” — I agree that food shortages (relative to demand) are a looming problem — and that research the Gates Foundation is funding to improve photosynthesis will help.  I’m not so sure about the latter claim.  Although the RIPE project has an impressive list of publications — it must be great to have so much funding, or even a little! — I’ve previously explained my doubts about one paper Bill Gates highlighted, which claimed to have improved on photosynthetic mechanisms shaped by millions of years of evolution.  See also a brief reference to this claimed advance in Tony Fischer’s essay on “Expensive Distractions” in the abstracts of last year’s meeting on “Making Science Useful in Agriculture.”

I was delighted that responses to Bill Gate’s tweet from Karl Schmid and Detlef Weigel referred to Jacob Weiner’s recent, insightful essay, “Looking in the Wrong Direction for Higher-Yielding Crop Genotypes” and my book, Darwinian Agriculture.   Weiner and I  both argue that fundamental processes like photosynthesis have already been improved so much by past natural selection that further improvements will be very difficult.  Instead,  improvements in crop yield are more likely to come from exploiting tradeoffs between individual-plant fitness (often at the expense of neighbors) and the collective performance of plant communities.  These tradeoffs were key to the doubling of wheat and rice yields during the Green Revolution — specifically, tradeoffs linked to plant height — a feat never approached since.  Radical innovations never tested by past natural selection may be possible, but betting so much of our research portfolio on that dream seems very risky.

For some new ideas, watch for my essay in the December issue of American Journal of Botany.