Darwinian Agriculture: How Understanding Evolution Can Improve Agriculture

by R. Ford Denison

As human populations grow and resources are depleted, agriculture will need to use land, water, and other resources more efficiently and without sacrificing long-term sustainability. Darwinian Agriculture presents an entirely new approach to these challenges, one that draws on the principles of evolution and natural selection.R. Ford Denison shows how both biotechnology and traditional plant breeding can use Darwinian insights to identify promising routes for crop genetic improvement and avoid costly dead ends. Denison explains why plant traits that have been genetically optimized by individual selection--such as photosynthesis and drought tolerance--are bad candidates for genetic improvement. Traits like plant height and leaf angle, which determine the collective performance of plant communities, offer more room for improvement. Agriculturalists can also benefit from more sophisticated comparisons among natural communities and from the study of wild species in the landscapes
where they evolved.Darwinian Agriculture reveals why it is sometimes better to slow or even reverse evolutionary trends when they are inconsistent with our present goals, and how we can glean new ideas from natural selection's marvelous innovations in wild species.

Genres: Agriculture, Science, Nonfiction, Evolution, Popular Science

272 pages, Hardcover

First published July 2, 2012

Reviews

[Sarah · Rating 4 out of 5]

This book was much more "big picture" than a lot of other agricultural books (which is probably evident from the title). Instead of focusing on traditional, biotech-focused methods for increasing yields, the author discusses ways to reorganize the way we do things, and to think about "improvements" in terms of tradeoffs and complexities. As he states multiple times, natural selection would not likely have missed simple, tradeoff-free improvements in yield. For example, if a plant produces more grain, it cannot allocate as much energy to growing taller, which may affect its ability to get enough sunlight. Biotechnologists cannot assume that there is a simple way to fix certain aspects of a plant -- e.g. rubisco is a "terrible" enzyme, but it has had millions of years of selective pressure applied to it, and "fixing" it is not going to be practical or maybe even possible without negatively affecting some other aspect of the plant. In addition, mimicking natural settings may not be the way to go about doing things, although it is the initial response many people have when faced with the desire to improve agriculture.

While the first few chapters were fairly pessimistic about the future of agriculture, the final few chapters were much more optimistic and insightful. The author emphasizes a reversal of the build up of "arms race" adaptations. Traits that were selected for when plants were in natural settings, having to compete with other individuals, are not necessarily applicable in an agricultural setting, where humans eliminate most competitors. In addition, applying group selection (favoring cooperation between plants, between animals, between plants and animals) to agricultural practices appears to have great potential.

Very interesting, and a refreshing perspective on agriculture.

[Geoffrey Benn · Rating 4 out of 5]

I strongly recommend this book to anyone involved in or interested in plant breeding, biotechnology, or agriculture generally. Denison takes an evolutionary perspective on current efforts to improve agriculture. He is equally critical of both biotechnology-based and organic approaches (a refreshing change in a highly polarized field) and tries to use evolutionary ideas to suggest which approaches are likely to be successful. While I don't agree with all of his conclusions, he lays out an invaluable framework for thinking about crop improvement that I think could be beneficial to anyone in the field.

[Philipp · Rating 4 out of 5]

A very interesting take on agriculture with a focus on plants and their future - the author applies Dawkin's selfish gene concept to explain and hypothesize about various concepts floating around agriculture right now.
He's got three basic ideas on which the book is based on - the first is that natural selection doesn't miss easy ror tradeoff-free improvements; in these chapters there's disappointment in the promises of GM-advocates, as the "low hanging fruits" of plant improvement may not exist. I don't fully agree with this - after all, evolution hasn't stopped and given us perfect species, and without the fitting natural selection, the low hanging fruit may still be there - but I can see what he means.

The second point is that competitive success is better than success by persisting - for example, forests or ecosystems usually don't compete against each other, so there is no telling whether their actual composition is "ideal" or not - maybe yes, maybe no, the point is that the blind copying of this abundance can either help or hurt, we have no clue as to what outside pressures these compositions developed. Just because they have persisted doesn't mean that should blindly copy them.

In these chapters are the best (and most science-fiction-ish) ideas - for example, wheat grows larger because of inter-individual competition for light, which isn't good for us humans since then yield is lower, the plant has to put resources into growing instead of into our food. Borlaug reversed this process by introducing dwarf wheat with a much higher yield. Denison propose that we create plants that actually cooperate each other, for example, by making sure that plants in the vicinity get enough light, while the plants grow in such a way that harmful weeds are shaded. Quite outlandish, but doable! There's also a very interesting discussion on assisting plants in selecting for "helpful" rhizobia in varying nodules.

Right now our only successes in plant modification is that they express toxins, which is relatively easy, it's just a single gene that isn't particularly part of any system. If you start to modify salinity resistance, for example, the image gets bleaker - we've had some success by introducing ion pumps from salinity-resistant species, but these systems are still too unknown to drastically improve yield. Changing species so that they cooperate, that's still far, far away.

The third point is a relatively obvious one - we should always hedge bets and not bet on just one approach, this chapter is a bit more political as it includes various taxing schemes (an interesting Nitrogen-tax is proposed where farmers pay per kg of Nitrogen used, but get a tax bonus for every kg that is actually used - for example, 1000kg of wheat use 23kg of Nitrogen, so these 23kg would receive a bonus).

I don't always agree with his ideas, for example, he's a bit disappointed that so much money is being poured into the various -omics approaches while the "classic" fields of ecology and agronomy are being underfunded, he's disappointed that so many people work with Arabidopsis while there are so many alternative plants to work at, but I think that the omics stuff is still so early, and we still know so little about other, more complicated plants that it makes sense to keep on working with the relatively simple Arabidopsis.. For now. Some people try to model the human brain, but more people are working on the simple C. elegans with its exactly 302 neurons.

Bonus quote:

Do legumes, like the farm-owners in The Grapes of Wrath, advertise more openings than actually exist, to attract a surplus of applicants?

Recommended for: Plant biologists, breeders, interested laymen, people interested in the future of agriculture, people interested in the big picture

[John · Rating 3 out of 5]

"Darwinian Agriculture" is insightful. It focuses significant field experience and a literature review into a clear point of view clearly supported by a small core of scientific principles of Darwinian evolution, focusing on exactly where selective pressure is applied. This point of view allows for a number of really good ideas, as well as some powerful criticism.

It's not a fun book as a whole; it's a book of a person whose generosity has been seriously taxed by seeing the same misconceptions over and over, and seeing those misconceptions get funding instead of a broader range of ideas. It leads the author to some really troubling points, such as suspecting methodological problems in some contrary research results. (In particular, he suspect polycultural overyielding is overreported, as the monocultural controls are often not handled optimally, and monocultural successes might be underreported as all null hypothesis results can be.) On one hand, I definitely agree that this particular research potentially has this problem, but on the other hand, it's troubling to present potential research biases only from one's ideological enemies.

Despite this, the book holds a lot of fun moments, particularly in the second half. I particularly enjoyed the cleverness of "push-pull" pest-management strategies, which leave enough land unguarded by a particular set of chemicals as to not create too strong a selective pressure for resistance. I'd also like to highlight great ideas about group selection of more cooperative soil biota.

I can't help wonder what the author would think of Mark Shepard's "Restoration Agriculture" and the research into these practices being undertaken at UIUC and elsewhere, which uses ecological approaches to agriculture in a way both similar and very different from agroecological framings he criticizes. He would probably raise the same questions I do, which is whether the broad-spectrum nutritional advantages would still hold up amortized over multiple acres. However, I like to imagine he would see this as one of may approaches to hedging our bets through a variety of strategies.

Having said that, this is still the book of a person who makes a very strong distinction between cultivated, settled, and natural landscapes, and there are a number of arguments that hinge on multi-function solutions not being acceptable. That makes some amount of sense, as over the short term this does likely mean greater human intervention into wilderness. Still, if we want broader ecosystem service support, we have to consider this potential range of bets.

In the last chapter, the book had some very positive things to say about bet-hedging and trying a variety of strategies at the cost of optimization on the basis of what we know. I think if the book had been given a framework on the basis of articulating different strategies from the beginning, weighing the trade-offs of different designs and hedging between them, it might have been presented a more cohesive vision, indeed a more designed, generous, and engaging vision, for the future of agriculture. As it stands, there are a lot of well-motivated ideas for future agricultural research, and that's still a great contribution.

[Angela · Rating 5 out of 5]

A delightful and refreshing read. Thoughtful, thought-provoking, measured, and compassionate. A subtle hint of playfulness (“Egypt reportedly found a seven-year supply [of grain] to be adequate.”) and wordplay (“Where Does Nature’s Wisdom Lie?”) bubbles up throughout the text. A well curated list of references. Big picture in a good way—substantiated by specific examples. Takes both a historical view and a multi-disciplinary view. A balanced discussion of the tradeoffs inherent in every agricultural choice. Overall, a compelling case for understanding and harnessing the principles of natural selection in agricultural research.

[Donato Colangelo · Rating 5 out of 5]

I'd pay gold to have Denison as professor, really.
There is no amount of words that can describe just how good and inspiring this book is. And how down to Earth the discussion of the topics really is.
A book worth of translating in all languages given the importance of the subject in the face of the challenges that awaits us in the future.

I suggest this title to everyone. E-v-e-r-y-o-n-e. Seriously.