Category: Genetic erosion

Posted on

Indications of failure

ResearchBlogging.orgA group of over 20 biodiversity experts from a slew of international conservation agencies have a paper out in Science bemoaning the state of the biodiversity indicators agreed in 2006. ((Walpole, M., Almond, R., Besancon, C., Butchart, S., Campbell-Lendrum, D., Carr, G., Collen, B., Collette, L., Davidson, N., Dulloo, E., Fazel, A., Galloway, J., Gill, M., Goverse, T., Hockings, M., Leaman, D., Morgan, D., Revenga, C., Rickwood, C., Schutyser, F., Simons, S., Stattersfield, A., Tyrrell, T., Vie, J., & Zimsky, M. (2009). Tracking Progress Toward the 2010 Biodiversity Target and Beyond Science, 325 (5947), 1503-1504 DOI: 10.1126/science.1175466)) These indicators are important because they are supposed to be used to track progress towards fulfillment of the promise made by Parties under the Convention on Biological Diversity to reduce the rate of biodiversity loss by 2010. They have also been incorporated into the Millennium Development Goals.

The authors point to problems with the “availability, consistency, and relevance” of data on even the indicators that are reasonably well-developed at the global scale. Some indicators — 5 of the 22 — “are not being developed at a global scale” at all, such as the one on access and benefit sharing. ((It occurs to me that, with the International Treaty in place, at least the agricultural biodiversity community has a pretty solid, ready-made indicator for ABS. But consider that “are not being developed” for a minute. Aren’t the authors’ organizations supposed to be leading the development of these indicators? What am I missing here? Is the paper a coded plea for less political interference?)) The next Conference of the Parties of the CBD (which meets in Japan in October 2010) “will review progress and agree on a new set of targets and a revised indicator framework.”

I hope one of the things it will consider in the new set of targets is crop genetic erosion. There are currently two indicators under the “Trends in genetic erosion” rubric, covering ex situ crop collections and livestock diversity respectively. Here’s what the indicators website has to say about the ex situ collections indicator:

Currently, studies are being undertaken to measure the dynamics of genetic diversity of collections from selected genebanks (EURISCO, USDA, SINGER, ICRISAT and CIAT), in order to develop a model to be applied more systematically worldwide. Based on data from these sources, the evolution over time in quantitative and qualitative terms (number of species; number of accessions/species; geographic origin and distribution of newly added accession versus existing ones) of collected samples was investigated.

I’m ashamed to say I know no more about it than that, but will try to find out the latest. Or maybe someone out there can bring us up to date. Anyway, there is no indicator that I can see on trend of genetic diversity in farmers’ fields, although there is one on sustainable management of agroecosystems.

We all know this is a fraught subject, not least politically, and we should perhaps be grateful that there is anything at all on agrobiodiversity among the indicators ((A tribute to our friends at Bioversity International and FAO, no doubt.)), but we cannot go on quoting at best anecdotal, at worst dubious, figures on loss of crop diversity and expect to be taken seriously. To say, as the authors of the Science paper do, that

…indicators of genetic biodiversity are slowly being compiled for domesticated and cultivated varieties but not yet for wild relatives.

is frankly not hugely reassuring.

Posted on

Nibbles: Légumes oubliés, Mazes, Poultry, Business, Roquefort, Herb, Evolution, Benin, Egyptian pigs, New York food, Cabbage pest control, Cider making

Posted on

Mapping banana diseases by phone

…Grameen Foundation, the International Institute for Tropical Agriculture (IITA) and Uganda’s National Agriculture Research Organization (NARO) designed a pilot project to test if data collection and transmission through the use of mobile phones (and GPS units) is a viable alternative to tradition[al] agriculture extension. The project team used identifying, mapping, monitoring and controlling banana disease as a case study to model this new agriculture extension system.

Interesting, no? And, it seems, quite effective. You can read about some of the results at AGCommons. Who’s going to be the first to use mobile phones to map and monitor crop (or crop wild relatives) diversity?

LATER: The BBC has a piece on software for mobiles that will support this kind of application.

Posted on

Twice as much conserved, or about the same extinct?

Ask how much crop diversity has been lost in the past century or so and one answer is bound to come up. “[A]pproximately 97 percent of the varieties given on the old USDA lists are now extinct. Only 3 percent have survived the last eighty years.” That’s how it appeared in the 1990 book Shattering: Food, Politics, and the loss of genetic diversity, and that’s one of the numbers that has become accepted as a scary measure of genetic erosion.

Pat Roy Mooney and Cary Fowler took a list of vegetable varieties available from US seed catalogues in 1903 and asked how many of them were still held in the USDA National Seed Storage Laboratory in 1983. Their answer: 597 out of 8045, or 3%.

Except that, as is now obvious, 597 out of 8045 is not 3%.

A new paper by Paul Heald and Susannah Chapman at the University of Georgia in the USA says that the figure is wrong, on two counts. First, there’s the little matter of a mathematical error in the original analysis, as presented in Shattering. Rather than 3% — the headline figure — the true survival rate is 7.8%. Or actually, if you count bits of a subsequent analysis by W.W. Tracy, the bloke who compiled the original 1903 list, 7.4%. Tracy noted, as many others have done before and since, that a single variety may go under more than one name. Thus of 578 garden bean varieties listed in the original study, only 185 represented distinct varieties. That difference is essentially trivial.

The other sense in which Heald and Chapman claim that the 3% (or 7.4%, or 7.8% — it really doesn’t matter) figure is wrong is that while 93% of varieties may have disappeared, they have been replaced by other varieties. In their survey of 2004 catalogues, Heald and Chapman count 7100 varieties, “only 2 percent fewer than one hundred years earlier. By this measure, consumers of seeds have seen almost no loss of overall varietal diversity”.

True, as far as it goes. But having berated Fowler and Mooney for not paying sufficient attention to multiple names, it would behoove Heald and Chapman to consider whether, among those 7100 varieties, the amount of genetic diversity is as great as it was in 1903, and whether gardeners are actually getting what they want.

This is certainly not the case in the UK and many other places in Europe, where, for example, there may be many more pea varieties available today, but none of them are the tall-growing varieties with an extended picking season that many gardeners say they would prefer. ((A fresh study of the losses associated with the UK’s National List and the EU Common Catalogue would be a good idea, come to think of it. Defra, are you listening?)) If I were a betting man, I’d bet that the same is true, though to a lesser extent, in the US.

Heald and Chapman recognize the problem of “how much diversity has been lost” in their summary:

If the meaning of diversity is linked to the survival of ancient varieties, then the lessons of the twentieth century are grim. If it refers instead to the multiplicity of present choices available to breeders, then the story is more hopeful. Perhaps the most accurate measure of diversity would be found in a comparative DNA analysis of equal random samples of old and new varieties, work that remains to be done.

Available to breeders? That’s hardly the point. In any case, I’m not sure the story is more hopeful. I agree that a DNA study would be interesting. Would it, though, change anyone’s perception?

Posted on

BBC Radio discovers African Leafy Vegetables

BBC Radio 4 has one of the longest-lived series devoted to all aspects of food: The Food Programme. Today’s broadcast looked at the importance of traditional African vegetables and fruits in nutrition, health, and offering farmers additional options for earning a better living. The programme rounded up many of the usual suspects from among our friends at Bioversity International, to very good effect. At least, that’s our opinion, and we’re sticking with it. Programme details are available at the Food Programme’s web site, which also has links that let you listen online. We’re hoping the episode will go into the archive, in which case we’ll post a link to that here. If not, well, there are other options …