환금작물의 종자다양성이 지난 100년에 걸쳐 크게 변하였다

The National Geographic Society presented a tree in their July 2011 issue that purports to describe a loss of biodiversity among vegetable seeds available to horticulturalists in the USA, based on a 1983 study by RAFI.


Their website currently says:

As we've come to depend on a handful of commercial varieties of fruits and vegetables, thousands of heirloom varieties have disappeared. It's hard to know exactly how many have been lost over the past century, but a study conducted in 1983 by the Rural Advancement Foundation International gave a clue to the scope of the problem. It compared USDA listings of seed varieties sold by commercial U.S. seed houses in 1903 with those in the U.S. National Seed Storage Laboratory in 1983. The survey, which included 66 crops, found that about 93 percent of the varieties had gone extinct. More up-to-date studies are needed.

Yes indeed, more up to date studies that those of 1983 are needed, and several are readily  available if you do some research. The tree based on the 1983 study (reproduced above) is only part of the story which has emerged in recent years, and fortunately the more complete and complex modern picture is much more hopeful. A table and a figure showing some the more up-to-date different findings, and reference to three relevant reports the National Geographic missed are presented below. one of the strongest is a recent peer-reviewed study de Wouw et al 2010 (see figure at the end of this post) that paints a very different story to the National Geographic article.

CROP DIVERSITY REPORT CARD FOR THE TWENTIETH CENTURY: DIVERSITY BUST OR DIVERSITY BOOM? 

Paul J. Heald Allen Post Professor of Law University of Georgia
Susannah Chapman Ph.D Student, Anthropology University of Georgia
August 27, 2009

 According to the conventional wisdom, the twentieth century was a disaster of monumental proportions for vegetable crop diversity. 1 The conventional wisdom is wrong. Our study of 2004 commercial seed catalogs shows twice as many 1903 crop varieties surviving as previously reported in the iconic 1983 study on vegetable crop diversity. More important, we find that growers in 2004 had as many varieties to choose from (approximately 7100 varieties among 48 crops) as did their predecessors in 1903 (approximately 7262 varieties among the same 48 crops). In addition, we cast doubt on the number of distinct varieties actually available in 1903 by examining historical sources that expose the systematic practice of multiple naming. Finally, by looking more closely at the six biggest diversity winners of the twentieth century (tomatoes, peppers, lettuce, garden beans, squash, and garlic), we suggest that patent law is virtually irrelevant.

By previewing this sub-section of a much larger study, we hope to initiate a debate on what scientists, economists, anthropologists, and the media should mean when they invoke a value-laden word like “diversity.”

By far the most influential study of vegetable crop diversity was conducted in 1983 by the Plant Genetic Resources Project of the Rural Advancement Fund. 2 Although it was unpublished, its findings were widely publicized and accepted. In 1990, Pat Mooney and Cary Fowler, who headed the International Conference and Programme on Plant Genetic Resources at the Food and Agriculture Organization of the United Nations, reprinted the study in its entirety in their influential book, Shattering: Food, Politics, and the Loss of Genetic Diversity. The 1983 study compared a comprehensive 1903 USDA inventory of seeds found in commercial seed catalogs with the 1983 holdings in the National Seed Storage Laboratory (NSSL). Fowler summarized the study as follows, “RAFI found that approximately 97 percent of the varieties given on the old USDA lists are now extinct. only 3 percent have survived the last eighty years.”3 The 3 percent survival rate is the iconic crop diversity statistic produced in the twentieth century.

Since the 1903 USDA inventory surveyed commercial availability in seed catalogs, we decided to update the 1983 RAFI study by measuring commercial availability in 2004 seed catalogs. Unlike RAFI’s, our approach parallels the USDA’s methodology, and it provides a snapshot of the market more than 25 years after RAFI’s landmark research. For 48 different vegetables,4 we report below the number of varieties listed in the 1903 USDA study, the 1903 varieties surviving in 1983 in the NSSL,5 the 1903 varieties surviving in 2004 commercial seed catalogs, and the total number of varieties available in 2004. We also report partial information on vegetable patents.

FINDINGS:
Rate of Varietal Loss Since 1903: Of the 7262 varieties listed in the 1903 USDA inventory, only 430 are still available in commercial seed catalogs, a 6 percent survival rate. In other words, 94 percent of the old varieties are no longer available from the most common commercial sources. By this measure, the twentieth century witnessed a significant loss of diversity.
Rate of Varietal Replacement Since 1903: In 1903, buyers of seeds had the choice of 7262 varieties of the 48 vegetable crops studied. In 2004, buyers had the choice of 7100 varieties of the same set of vegetables, only 2 percent fewer than one hundred years earlier. By this measure, consumers of seeds have seen almost no loss of overall varietal diversity.
Diversity Winners and Losers: Growers of garden beans, garlic, lettuce, peppers, squash, and tomatoes, have many more choices in 2004 than they did in 1903. For beans, the number of varieties increased from 1858 to 771, for garlic from 3 to 274, for lettuce from 1079 to 520, for peppers from 126 to 674, and for tomatoes from 408 to 1518. on the other hand, growers of sugar beets (only 11 varieties compared to 178), cabbage (81 varieties compared to 544), field corn (177 compared to 474), radishes (138 varieties compared to 463), and rutabaga (168 varieties compared to 29) have vastly fewer choices.
Sources of Varietal Replacement: Although our research is incomplete on this issue, a casual review of 2004 varieties suggests that the large number of available varieties is due to the combined efforts of preservationists who have identified and maintained many old varieties not for sale in 1903, importers who have brought new varieties into the United States, and innovators who have bred new varieties....

SUMMARY: The primary argument for maintaining crop diversity is based on the need to maintain a safety net of genetic diversity, to have a broad supply of genes available to breeders who can create more productive, weather-hardy, insect resistant, fungus resistant, and better-tasting crops. We hope our findings stimulate a discussion about the proper measure for that diversity. 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.

Table comparing commercially available seed variety numbers in 1903 versus 2004, from Heald and Chapman 2011

See also

Veggie Tales: Pernicious Myths About Patents, Innovation, and Crop Diversity in the Twentieth Century
Paul J. Heald
University of Illinois College of Law; Bournemouth University - Centre for Intellectual Property Policy & Management (CIPPM)
Susannah Chapman
University of Georgia Department of Anthropology
September 16, 2011
Illinois Program in Law, Behavior and Social Science Paper No. LBSS11-34
Illinois Public Law Research Paper No. 11-03

Abstract:     
The conventional wisdom, as illustrated for millions of readers in the July 2011 issue of National Geographic, holds that the twentieth century was a disaster for crop diversity. In the popular press, this position is so entrenched that it no longer needs a citation. We conduct a study of all vegetable and apple varieties commercially available in 1903 and compare them with all varieties commercially available in 1981 and 2004. We question the conventional wisdom and cast serious doubt on the 1983 study that previous commentators have taken as gospel. We also enter the debate between economists and social scientists on the role that patent law might play in destroying or enhancing crop diversity. Both sides may be wrong. Our data suggest that patent law has not reduced crop diversity, nor has it likely significantly contributed to the introduction of new vegetable varieties. The diversity loss thesis espoused by ethnobotanists is as suspect as the incentive-to-invent story told by patent economists, at least as regards the most common vegetable crops. Finally, we provide one of the first analyses of innovation in any comprehensive technology market by identifying the source of all products in the market and current commercialization rates for all patented innovations. This paper goes significantly beyond our prior three related postings of preliminary data.



 Genetic diversity trends in twentieth century crop cultivars: a meta analysis. 
van de Wouw, M., van Hintum, T., Kik, C., van Treuren, R., & Visser, B. (2010) TAG Theoretical and Applied Genetics, 120, 6, pp  1241-1252 (Free Access)

Abstract In recent years, an increasing number of papers has been published on the genetic diversity trends in crop cultivars released in the last century using a variety of molecular techniques. No clear general trends in diversity have emerged from these studies. Meta analytical techniques, using a study weight adapted for use with diversity indices, were applied to analyze these studies. In the meta analysis, 44 published papers were used, addressing diversity trends in released crop varieties in the twentieth century for eight different field crops, wheat being the most represented. The meta analysis demonstrated that overall in the long run no substantial reduction in the regional diversity of crop varieties released by plant breeders has taken place. A significant reduction of 6% in diversity in the 1960s as compared with the diversity in the 1950s was observed. Indications are that after the 1960s and 1970s breeders have been able to again increase the diversity in released varieties.
Thus, a gradual narrowing of the genetic base of the varieties released by breeders could not be observed. Separate analyses for wheat and the group of other field crops and separate analyses on the basis of regions all showed similar trends in diversity.

Figure from De Wouw et al 2010

H/T. Klaus Ammann

Also, kindly thanks to Jeremy from the comments:
Brothers in farms
by LUIGI GUARINO on MAY 25, 2012

and other more developed discussions at Agricultural Biodiversity Blog