- Buy Haiti’s Francis mangoes!
- The Muge dog was, in fact, a dog.
- Looking at the grapevine in its center of origin.
- Need to fence lavender populations in Tunisia to protect them.
- More Mediterranean stuff. History of the mastic trade in an Aegean island.
- Making “drunken rice” in Korea. Sign me up.
- Nutella to come with warning label? Jeremy says: We don’t need no nanny state!
- Bluish mozzarella balls confiscated. Jeremy says: Ok, maybe we do after all.
- EU makes itself useful and protects bacon pig of choice, with built-in apple sauce to boot.
- “…finding how the physical and chemical composition of different cowpea varieties influence human health, reduce obesity and prevent diseases like cancer, hypertension and heart related ailments.”
Saving crops through mechanization on three continents
While irrigation and market improvements could help, it would be reduction of processing time from hours to minutes made possible by mechanical hullers that might achieve most, “allowing women to take advantage of both their preferences for reduced labour loads and for the taste of millets in their everyday diets.”
I’ve quoted this before. It comes from a study looking at how so-called “minor” millets could be revitalized in India. A similar story of rescue of a traditional crop through the mechanization of processing is unfolding on another continent for quinoa. I was reminded of both by reading about the recent history of maize processing in Mexico on Rachel Laudan’s blog, which we have also blogged about.
…in Mexico, right up until about twenty years ago, large numbers of Mexican women were spending five hours a day grinding. Just imagine Mexico City: every household had somebody grinding tortillas. The landscape of Mexico City up until fifty years ago, and in many ways even later, is one of bakeries that make wheat breads for the upper class or perhaps for breakfast or the evening meal, and then in every household, somewhere in a back room, somebody grinding maize to make tortillas for the main meal of the day.
This has been completely changed, of course, by the wet-grinding mill, the tortilla-making machine, and finally, quite recently, the dehydration and packaging of wet-ground maize. One wonders whether bread would have made more of an inroad into Mexican cuisine, culture or no culture, if it hadn’t been for this revolution in processing. The resulting tortillas don’t taste as nice as home-made, but that’s a price most are willing to pay.
Mexican women that I have talked to are very explicit about this trade-off. They know it doesn’t taste as good; they don’t care. Because if they want to have time, if they want to work, if they want to send their kids to school, then taste is less important than having that bit of extra money, and moving into the middle class. They have very self-consciously made this decision. In the last ten years, the number of women working in Mexico has gone up from about thirty-three percent to nearly fifty percent. One reason for that—it’s not the only reason, but it is a very important reason—is that we’ve had a revolution in the processing of maize for tortillas.
Is a similar trade-off to be expected for those Indian millets and quinoa? And if so, can anything be done about it? In Mexico, they are already coming up with better tortilla machines “that rotate and flip the tortillas like you do on the comal, so they’re much closer to the taste of the handmade ones.” So says Rachel Laudan, adding: “…I think there will be a movement for good tortillas.” What I want to know is whether these tortilla machines will come to East Africa, so that we can eat maize meal in forms other than the very dull ugali.
Nibbles: Maize, Millets, Pollinators, Ungulates, Drugs, Orchids
- Long article on the politics (and more) of maize in Mexico.
- Yet more on the slow comeback of millets in (parts of) India.
- International Conference on Pollinator Biology, Health and Policy on July 24-28, 2010 at Penn State.
- Hunted ungulates are semi-domesticated.
- “…psychoactive plant toxins were a mundane occurrence in the environments of hominid evolution, and our ancestors may have been exploiting plant drugs for very long periods of time.”
- “I was confronted with centrefolds showing downy, smooth petals and moistened, hot-pink lips that pouted in the direction of tautly curved shafts and heavily veined pouches.”
Nibbles: Protected areas, Sturgeon, Geographic indications, Ugandan yams, Tomato controversy, Maya agriculture, Alternatives to slash-and-burn, Asian veggies, Food composition
- Bird people say: Critical migratory waterbird sites need urgent protection. Tomato and potato crop wild relative people say: What, only the critical ones? You’re lucky, mate!
- Toffs everywhere start stocking up on caviar.
- Tequila and cheese geographically indicated. Foie gras says: Been there, done that, got the t-shirt.
- Uganda Government minister says yams cause cancer. Oh, come now, steady on.
- Are Tomatoes Fruits or Vegetables? Asks mental_floss. Oh no, I’m not going there, says me.
- “…where there is a market, the Maya will work to develop supply capability; where there is no market, traditional subsistence methods are better than the introductions.”
- Building a better slash-and-burn agriculture.
- Nice Asian greens. I’m hungry already.
- Crop Composition Database gets facelift.
The return of ex situ
Although some have emphasized the need to breed crops for future climatic conditions, much of the world’s farming population relies on landrace populations, not formal breeding networks.
Undeniable, of course, and a good reason to not forget landraces (farmers’ local varieties) when thinking about how agriculture will (or will not) adapt to climate change. The new paper by Kristin Mercer and Hugo Perales in Evolutionary Applications from which the above quotation is taken (minus the references for clarity, as with all subsequent quotes) won’t let you forget. ((Mercer, K., & Perales, H. (2010). Evolutionary response of landraces to climate change in centers of crop diversity Evolutionary Applications DOI: 10.1111/j.1752-4571.2010.00137.x))
The authors look in some detail at each of the possible responses that landraces may have to climate change. They could simply “adjust their phenotype” (plasticity). Or they could adjust their genotype, otherwise known as evolution, and thus “keep up” with the climate. They could also migrate to more hospitable places. And, finally, they could die out (extinction).
What will determine which of these routes any particular landrace follows? Mercer and Perales think two main factors need to be considered: the level and pattern of adaptive genetic variation in the landrace, and the details of how climate, and therefore selection pressures, will actually change. They say they recognize that what farmers do will also determine the outcome, but somewhat disappointingly leave a discussion of that to a later date. They list about a dozen quite specific research questions that would need to be tackled to “understand how landraces in crop centres of diversity may respond to climate change,” which I’ll reproduce in full for those who don’t have access to the paper (they’re in Box 1).
Genetic structure
• Is available genetic variation appropriate for evolutionary response to climate change, especially for selfing or clonal crops?
• At what rate will evolution proceed given heritability of traits and strength of selection?
• Might there be constraints on evolution to multiple environmental changes given the genetic correlations among traits?
• Is there capacity for evolution of plasticity?
• Might populations be plastic in response to climate change, especially for selfing or clonal crops?
• Will different types within a species, or landraces from different regions, respond differently?
• Will adaptive or novel variation be available to populations for evolution based on patterns of gene flow and mutation rates?
• Would gene flow from improved varieties improve or reduce the evolutionary potential or plastic response of landrace populations?Climate change patterns
• What aspects of climate change will impose directional, disruptive, or fluctuating selection?
• Could selection be strong enough to reduce genetic variation within or among populations?
• Could it reduce effective population size or cause major mortality, which should reduce genetic variation?
• Would yearly variability in selection reduce genetic variation or lead to greater plasticity?
That’s a nice research agenda to be getting on with. I was particularly interested in three specific observations made by the authors. The first is that “[f]armer-mediated selection may … contradict natural selection.”
…farmers could select for seed characteristics, such as grain size, which, if negatively correlated with the tolerance to heat during the grain filling stage, could reduce the populations’ productivity in high temperatures.
The second is that
Migration or gene flow could facilitate adaptation and maintenance of productivity with climate change because gene flow can introduce novel variation into landrace populations on which selection can act. (Mutation can also introduce novel and potentially adaptive variation, which could be selected upon as climate shifts.) In contrast, gene flow could constrain adaptation if there is repeated introduction of alleles from maladapted landrace populations.
Where would such non-maladapted material come from? The authors don’t really discuss this question, but we suggested in a recent paper that in many situations the source may well be a different country.
Finally, the authors point out that “since climate change is promised to introduce new extremes in temperature,” the resulting “strong bouts of selection” are quite likely to cause extreme narrowing of genetic diversity in landraces when they don’t cause their extinction.
These points, and indeed others, could only lead to one conclusion as far as I was concerned, and I read on anxiously to see whether the authors would agree. Finally, on the penultimate paragraph, the money quote arrived:
Ex situ conservation could regain primary importance despite the fact that it is an already over-taxed system. Yet climate change promises to complicate the decisions of which locations are most appropriate for grow-outs.
Remember that the paper is written very much from the perspective of in situ conservation. To see the importance of genebanks extolled so clearly in such a context, and the complexity of their operations highlighted to boot, was very welcome, and I must say somewhat unexpected. Are we beginning to move back towards a recognition of the essential complementarity and inter-dependence of ex situ and on farm conservation?