Robert Hijmans’ third dispatch from Davis. Previous one here. Keep ’em coming, Robert!
Day 3 of the Harlan II symposium had another cornucopia of fine presentations. Farmed fish, genetic chips, fruits for the poor, improving desert crops, ecosystems services research, transgenic goats, selling diversity to the rich to name a few topics. One subject shared by several talks was on-going and future domestication.1 From conservation to innovation.
Dennis Hedgecock described the big wave of domestication in our time: aquaculture. Within a decade or so, there will be more fish produced on farms than caught in the oceans. The ocean catch won’t increase much any more (or worse); we have reached the limits. And how wild is caught fish anyway? Fish stocks in the ocean are increasingly being replenished with small fish from hatcheries. The majority of Japanese fish descends from hatchery fish. Whether this is good or bad for the genetic diversity of the fish depends how it is done. Guess how it is done.
Overfishing of oceans and the subsequent shift to farming is strikingly similar to the domestication pathways of some land animals that were also hunted before they were domesticated (discussed yesterday by Melinda Zeder). So what is all this fish farming about? Shrimp, salmon, tilapia? No. Number 1 is the Pacific Oyster and 60% of fish farming is carp production in China.
The breeders are at it too. They have developed a tetraploid Pacific Oyster. Crossing it with the normal diploids creates infertile, but larger, triploid offspring. They are not being commercially produced yet, but here aquaculture mimicks plant domestication.
Roger Leakey described a project of further or re-domestication of tree crops. Going into villages in West Africa, Leakey and colleagues asked farmers what trees they valued and would like to have more of. They then looked at the variation in the species, selected some with good fruits, and helped find a place for them in the farming system, e.g. as shade crop in cacao. Seems like fairly simple work, if labour intensive.
In some places the result was stunning, with very poor farmers earning an extra US$700 per year from a few trees in their field. Diversity can improve livelihoods of poor farmers. We will need to revise the agronomy curricula to make it happen on a large scale.
Meanwhile, in India, good old pigeonpea is being renewed. Landraces are perennial bushy plants. But Laxmipathi Gowda and collaborators at ICRISAT have produced many other types: short duration; determinate; daylength insensitive; and even hybrids. And in California there might be renewed attempts to use jojoba, now for bio-energy. Stephen Kaffka talked about some of the difficulties of domesticating a highly heterozygous, variable, and slow growing shrub. So far there is no evidence that we can use our new molecular biology prowess to reduce the domestication process from 1000(0) years to 10.
Food trends start in California, said Karen Caplan. Perhaps she is right. Perhaps most societies will go through an agrobiodiversity bottleneck when they urbanize; but then bounce back when they get rich enough. In a respectable farmers’ market here in Northern California there will — in the right season — always be a stand with only tomatoes, and a least twenty varieties of them. The weirder the shape the better, as long as they taste good. Guess what I had for dinner in my Best Western hotel. T-bone steak? No, a heirloom tomato salad.
Caplan discussed some of the inner workings of getting more agricultural biodiversity through the modern food-chain. Flavor is king. Ignore obstacles. Use influencers such as TV cooks and movie stars to rave about your new potato or brassica. Get it mentioned on a blog.
- Domestication in the not very strict sense of using more of relatively little exploited biological resources. [↩]