Stephen Brush | University of California, Davis (original) (raw)

Papers by Stephen Brush

Revue d’ethnoécologie, 2021

Scientific Reports, 2020

Olive tree is a vector of cultural heritage in Mediterranean. This study explored the biocultural... more Olive tree is a vector of cultural heritage in Mediterranean. This study explored the biocultural geography of extra virgin olive oil (EVOO) from the cultivar Ogliarola campana in Campania region, Italy. Here, the rich cultural elements related to olive tree and oil represent a suitable case study for a biocultural analysis. We joined analytical techniques, based on stable isotopes and trace elements of EVOOs, with humanistic analyses, based on toponymy and historical data. In order to provide a science-based assessment of the terroir concept, we set up a new method of data analysis that inputs heterogeneous data from analytical and anthropic variables and outputs an original global evaluation score, named terroir score, as a measure of biocultural distinctiveness of the production areas. The analysis highlighted two distinct cultural sub-regions in the production area of Ogliarola campana: a continental cluster in the inner area of Irpinia and a coastal one around Salerno province....

Click here if your download doesn"t start automatically Comparative Farming Systems Comparative F... more Click here if your download doesn"t start automatically Comparative Farming Systems Comparative Farming Systems Through a series of 12 original case studies, prepared by 19 international, multidisciplinary experts, this volume offers a comprehensive comparative examination of world agriculture. The 12 farming systems explored here encompass the broad array of environmental, demographic, and socioeconomic conditions in which agriculture exists-from Amazonian swidden to Hungarian cooperative farms. B.L. Turner II and Stephen B. Brush have provided a three-part classification of the systems based on output intensity, technology employed, and production goals. The contributors bring to their case studies the perspectives of anthropology, economics, geography, and rural sociology. Farming Systems will be a valuable reference work on individual farming systems, a rich source of comparative data for researchers, and a text for advanced courses in farming systems and world agriculture. Download Comparative Farming Systems ...pdf Read Online Comparative Farming Systems ...pdf Online Comparative Farming Systems ebook PDF download Comparative Farming Systems Doc Comparative Farming Systems Mobipocket Comparative Farming Systems EPub

While prevailing theories of crop evolution suggest that crop diversity and cultural diversity sh... more While prevailing theories of crop evolution suggest that crop diversity and cultural diversity should be linked, empirical evidence for such a link remains inconclusive. In particular, few studies have investigated such patterns on a local scale. Here, we address this issue by examining the determinants of maize diversity in a local region of high cultural and biological richness in Southern Mexico. We collected maize samples from villages at low and mid elevations in two adjacent municipalities of differing ethnicity: Mixtec or Chatino. Although morphological traits show few patterns of population structure, we see clear genetic differentiation among villages, with municipality explaining a larger proportion of the differentiation than altitude. Consistent with an important role of social origin in patterning seed exchange, metapopulation model-based estimates of differentiation match the genetic data within village and ethnically distinct municipalities, but underestimate differen...

New Phytologist

Crop diversity underpins the productivity, resilience, and adaptive capacity of agriculture. Loss... more Crop diversity underpins the productivity, resilience, and adaptive capacity of agriculture. Loss of this diversity, termed crop genetic erosion, is therefore concerning. While alarms regarding evident declines in crop diversity have been raised for over a century, the magnitude, trajectory, drivers, and significance of these losses remain insufficiently understood. We outline the various definitions, measurements, scales, and sources of information on crop genetic erosion. We then provide a synthesis of evidence regarding changes in the diversity of traditional crop landraces on farms, modern crop cultivars in agriculture, crop wild relatives in their natural habitats, and crop genetic resources held in conservation repositories. This evidence indicates that marked losses, but also maintenance and increases in diversity, have occurred in all these contexts, the extent depending on species, taxonomic and geographic scale, and region, as well as analytical approach. We discuss steps needed to further advance knowledge around the agricultural and societal significance, as well as conservation implications, of crop genetic erosion. Finally, we propose actions to mitigate, stem, and reverse further losses of crop diversity.

Human Organization

... That base emphasizes four aspects of anthro-pology: 1 ) the role of cultural factors in deter... more ... That base emphasizes four aspects of anthro-pology: 1 ) the role of cultural factors in determining social phenomena (the holistic aspect), 2) the importance of un-derstanding the local perspectives (the "ernie" view), 3) the value of case studies, and 4) the utility of participant ...

Society & Natural Resources, 1990

... Department of Applied Behavioral Sciences University of California Davis, CA 95616 CAROLYN PI... more ... Department of Applied Behavioral Sciences University of California Davis, CA 95616 CAROLYN PICKEL University of California Cooperative Extension Watsonville, CA 95076 FRANK G. ZALOM ... 1983; Glass 1975; Pimentel and Perkins 1980; Smith and Pimentel 1978). ...

Conservation Biology, Oct 1, 1995

Potato Diversity in the Andean Center of Crop Domestication STEPHEN BRUSH,* RICK KESSELI,f RAMIRO... more Potato Diversity in the Andean Center of Crop Domestication STEPHEN BRUSH,* RICK KESSELI,f RAMIRO ORTEGA,* PEDRO CISNEROS,§ KARL ... la conservación de germoplasma en cultivos amenazados por la erosión genética, teniendo en cuenta que los métodos de ...

Conservation Biology, Oct 1, 1995

Potato Diversity in the Andean Center of Crop Domestication STEPHEN BRUSH,* RICK KESSELI,f RAMIRO... more Potato Diversity in the Andean Center of Crop Domestication STEPHEN BRUSH,* RICK KESSELI,f RAMIRO ORTEGA,* PEDRO CISNEROS,§ KARL ... la conservación de germoplasma en cultivos amenazados por la erosión genética, teniendo en cuenta que los métodos de ...

Situ, 2000

This manual is intended for national programmes interested in supporting in situ conservation of ... more This manual is intended for national programmes interested in supporting in situ conservation of agricultural biodiversity maintained on-farm by farmers. It was written to provide a range of actors, including Ministries of Agriculture and the Environment, universities, research and extension institutions, non-government organizations (NGOs), and community based groups, with a comprehensive view of factors involved in designing and implementing a programme to support the in situ conservation of crop genetic ...

American Anthropologist, 1977

Journal of the Royal Anthropological Institute, 2016

Domestication, Evolution, and Sustainability, 2012

Some 15,000 to 10,000 years ago, humans started seeding and harvesting plants and maintaining ani... more Some 15,000 to 10,000 years ago, humans started seeding and harvesting plants and maintaining animals in order to augment the food they obtained from wild-growing plants and hunting. These seemingly simple activities set in motion a long-term process that has led to the dominance of agriculture as we know it today. With the exception of a few remaining hunter-gatherer groups, agriculture has now become the most important source of food for most people. Agriculture is also a major source of feed for animals and of fiber. This transition from hunting-gathering to agriculture was without a doubt one of the most significant eras in the evolution of humans. It allowed food production on a more intensive and efficient scale than ever before, eventually leading to population increases, labor specialization (and especially a nonagricultural sector), the formation of villages, cities, and states, and the rise of more hierarchical societies and states (MacNeish 1991, Barker 2006). The late Professor J. R. Harlan (1917-1998) understood that the complexity of the biological, societal, and environmental changes involved in the transition to agriculture, as well as their antiquity of up to 10,000 years, necessitated a multidisciplinary approach if one is to understand the factors and processes that have led to the "neolithic revolution." Anthropologists, archaeologists, climatologists, ethnobiologists, geneticists, geographers, linguists, physiologists, and other practitioners all contribute to the field of crop evolution studies. J. R. Harlan also expressed concerns that the very development and spread of improved crop varieties were leading to losses in crop biodiversity, well before concerns about biodiversity became common knowledge. He made clear how the knowledge of evolutionary processes in crops facilitated the conservation of biodiversity and its use in the development of improved crop varieties. The vision of Professor Harlan was the inspiration for the first Harlan Symposium, which took place in 1997 in Aleppo, Syria, at the International Center for Agricultural Research in the Dry Areas (ICARDA). That symposium was remarkable because it brought together plant scientists and archaeologists

The Journal of Environment & Development, 1996

Economic Botany, 1990

ISQzvme markers were u cd 10 Sllrw'Y Ih" gen"lIC mria!)/!llyofnon-blller pow/OC\ in 10 subsistenc... more ISQzvme markers were u cd 10 Sllrw'Y Ih" gen"lIC mria!)/!llyofnon-blller pow/OC\ in 10 subsistence./iRlds of Andeanfarmers al 3600-3850 In above sea level. Sixty Si'\"en percent oflhe "'{JnelJe.~ were /elrapfOtds corresponding 10 the 'pCClCX Solanum tuberosum ssp. andigcna, ! 4% Iv",rc /nplolds. probably corr;;spondllJg 10 /he speCies S. x ehaueha. and I JW) It'ere diploids corresponding 10 Ihc specics S. Slenotomum. S. phureja. and S gOD.ocalyx. The isozymc 111!ormall0I1 served to de/ermine Ihe consistency oflhe folk naming sySIi?m, We found a high degree ofcorrespondence bcllvecn farmer idcl1/1jicQIIO!1 and efectrophore/lc phenolypes. The consiSli!ncy 0/ Ihe ji)lk syslO:m In deurophoreric /errns depended on Ihe farmer who was In/ef l'icII'cd. The mosl common Incongruity COI1SISled ofcallmg dlj}erent deClrophor~lIc phUlo/ypes by Ihe sume \'(11'1('1.1' name. leadmg 10 a slighI undereslimation ofgenetIC I'anabilil\' /Jrcoenl ill Ihe jldds. The amount ofvaflabllity observed In the sample or Ihe Andean pOlalO poplila/lon was superIOr /0 Ihal present In /\lorl17 A mencan and l~'uropcan varieties, This was !neaswTd inlerrns ofnumbcr ofalleles, number 0/ elecrrophoreth phcnIJlypes and percelll of hcterozygosllY. This jmdlllg SUPPOriS Ihe impressiollihal () subslanlwf ([mOun I ofyel Ulu'Ap/olled vanabtllly r~matns in Ilndc()1I ,.•ola/o popl//alll)IlS. Evaluaeion bioqllllTl ica y popular de \<:1 variabilidad interespeeifica de las papas clIlti vadas en los Andes. Ell <'51,' traba}o se da a conoeer fos resultados de un estudlO f(CnCl;CO subrc '•aflcdadcs d(' papa dulce en los Andes, realuuda pOI' medlO de marcadarcs ISOenZ/I1UlliC/JS ell parcetas de subslstencia loca/izados entre 3600 y 3850 ,ilelros sobre e! nive! de! mar. 5e eneon/ra que 67% de {as variedades mues Ircadas ,':an IelraplOides de fa ('specie S. wberosum ssp, andigena, 14% Inpfoides probabfemell/e de fa espeCle S. x chaucha, y IJljlo dip/aides de las especles S. stenolOmllm, S. phureja und S. gonioealyx. La informaCion IsoenZimallca lue (Ill! en fa C'valuaCton de la /)I'e('lslon cle! sistema lolkforlco pam Idenllficar varu:dades. Sc ellcontro un allO grado dl! asoClaCion ('!/Ire ef 5ls/(,ma d'" etasljtcaclon usado POl' e! campesillo para deno/mllar sus \'ariedade~, J' los feno/lpos eleciroforell cos. La prCClsion del "t"lema de Ic//?Iltic/ad fofklorico en lermlnos dec/roforaicos dependlo del campeslI10 emrel'is/(jdo. La discrepanCia mas /recuen/(' entre los dos 5151('1'1'10$ de nomenclatura COnSlSlllJ en {{amar e/(ferenles jcnOI/pus c1eclroforc/icos con eI mislllo lIombre l•aTlelal. fo que rcsuflO cn una subesllinaCIi)n de la vartab/fldad gcnetico pre ('1/1(' ('II I(J~ campos. Ef I/II'eI de vanabIfldad observado en fa mueslro de PQfJQ.\ de la jJob!ac/lj" ane/ma Iu;; superior a/ ohsen'ado en ,'ariedades nortea II1crimnas.l' curopeas, La \'ariilliitidud .Ie midlo ell bose al mimcrode aldos, I1lfrnero dejenolipos eleclr%rellcos l' porcenlaje de heleroCigosidad. ESlos resultados es/an de ael/erdo COil la Impri?SI{)n general de que lodal'fa e-'oste mucha vanabllidad en rariedadcs de papa alldll1as que no ha sido alin explotada.

Human Organization

... Anne-Marie Ridgley received an MS in International Agricultural Developmentfiom the Universit... more ... Anne-Marie Ridgley received an MS in International Agricultural Developmentfiom the University of California, Davis (1991). ... 1980; Byerlee and Collinson 1980; Gladwin 1989; Rhoades 1987; Rhoades and Bebbington 1988; Shaner, Phillips and Schmehl 1982; Tripp 1985). ...

Human Ecology

This paper reconsiders two widely held hypotheses about the effects of the green revolution, that... more This paper reconsiders two widely held hypotheses about the effects of the green revolution, that it led to biological simplification and instability. The hypothesis of biological simplification (genetic erosion) is tested with evidence from Andean agriculture, where farmers maintain a significant degree of crop diversity even as the 3 , adopt modern crop varieties. The hypothesis of increased instability is tested with evidence from Asia where wheat and rice yields show no general pattern of increased instability. Neither of these hypotheses is confirmed. The conventional wisdom about the green revolution should be reconsidered with emphasis on resilience and variation in modernizing farming systems.

Revue d’ethnoécologie, 2021

Scientific Reports, 2020

Olive tree is a vector of cultural heritage in Mediterranean. This study explored the biocultural... more Olive tree is a vector of cultural heritage in Mediterranean. This study explored the biocultural geography of extra virgin olive oil (EVOO) from the cultivar Ogliarola campana in Campania region, Italy. Here, the rich cultural elements related to olive tree and oil represent a suitable case study for a biocultural analysis. We joined analytical techniques, based on stable isotopes and trace elements of EVOOs, with humanistic analyses, based on toponymy and historical data. In order to provide a science-based assessment of the terroir concept, we set up a new method of data analysis that inputs heterogeneous data from analytical and anthropic variables and outputs an original global evaluation score, named terroir score, as a measure of biocultural distinctiveness of the production areas. The analysis highlighted two distinct cultural sub-regions in the production area of Ogliarola campana: a continental cluster in the inner area of Irpinia and a coastal one around Salerno province....

Click here if your download doesn"t start automatically Comparative Farming Systems Comparative F... more Click here if your download doesn"t start automatically Comparative Farming Systems Comparative Farming Systems Through a series of 12 original case studies, prepared by 19 international, multidisciplinary experts, this volume offers a comprehensive comparative examination of world agriculture. The 12 farming systems explored here encompass the broad array of environmental, demographic, and socioeconomic conditions in which agriculture exists-from Amazonian swidden to Hungarian cooperative farms. B.L. Turner II and Stephen B. Brush have provided a three-part classification of the systems based on output intensity, technology employed, and production goals. The contributors bring to their case studies the perspectives of anthropology, economics, geography, and rural sociology. Farming Systems will be a valuable reference work on individual farming systems, a rich source of comparative data for researchers, and a text for advanced courses in farming systems and world agriculture. Download Comparative Farming Systems ...pdf Read Online Comparative Farming Systems ...pdf Online Comparative Farming Systems ebook PDF download Comparative Farming Systems Doc Comparative Farming Systems Mobipocket Comparative Farming Systems EPub

While prevailing theories of crop evolution suggest that crop diversity and cultural diversity sh... more While prevailing theories of crop evolution suggest that crop diversity and cultural diversity should be linked, empirical evidence for such a link remains inconclusive. In particular, few studies have investigated such patterns on a local scale. Here, we address this issue by examining the determinants of maize diversity in a local region of high cultural and biological richness in Southern Mexico. We collected maize samples from villages at low and mid elevations in two adjacent municipalities of differing ethnicity: Mixtec or Chatino. Although morphological traits show few patterns of population structure, we see clear genetic differentiation among villages, with municipality explaining a larger proportion of the differentiation than altitude. Consistent with an important role of social origin in patterning seed exchange, metapopulation model-based estimates of differentiation match the genetic data within village and ethnically distinct municipalities, but underestimate differen...

New Phytologist

Crop diversity underpins the productivity, resilience, and adaptive capacity of agriculture. Loss... more Crop diversity underpins the productivity, resilience, and adaptive capacity of agriculture. Loss of this diversity, termed crop genetic erosion, is therefore concerning. While alarms regarding evident declines in crop diversity have been raised for over a century, the magnitude, trajectory, drivers, and significance of these losses remain insufficiently understood. We outline the various definitions, measurements, scales, and sources of information on crop genetic erosion. We then provide a synthesis of evidence regarding changes in the diversity of traditional crop landraces on farms, modern crop cultivars in agriculture, crop wild relatives in their natural habitats, and crop genetic resources held in conservation repositories. This evidence indicates that marked losses, but also maintenance and increases in diversity, have occurred in all these contexts, the extent depending on species, taxonomic and geographic scale, and region, as well as analytical approach. We discuss steps needed to further advance knowledge around the agricultural and societal significance, as well as conservation implications, of crop genetic erosion. Finally, we propose actions to mitigate, stem, and reverse further losses of crop diversity.

Human Organization

... That base emphasizes four aspects of anthro-pology: 1 ) the role of cultural factors in deter... more ... That base emphasizes four aspects of anthro-pology: 1 ) the role of cultural factors in determining social phenomena (the holistic aspect), 2) the importance of un-derstanding the local perspectives (the "ernie" view), 3) the value of case studies, and 4) the utility of participant ...

Society & Natural Resources, 1990

... Department of Applied Behavioral Sciences University of California Davis, CA 95616 CAROLYN PI... more ... Department of Applied Behavioral Sciences University of California Davis, CA 95616 CAROLYN PICKEL University of California Cooperative Extension Watsonville, CA 95076 FRANK G. ZALOM ... 1983; Glass 1975; Pimentel and Perkins 1980; Smith and Pimentel 1978). ...

Conservation Biology, Oct 1, 1995

Potato Diversity in the Andean Center of Crop Domestication STEPHEN BRUSH,* RICK KESSELI,f RAMIRO... more Potato Diversity in the Andean Center of Crop Domestication STEPHEN BRUSH,* RICK KESSELI,f RAMIRO ORTEGA,* PEDRO CISNEROS,§ KARL ... la conservación de germoplasma en cultivos amenazados por la erosión genética, teniendo en cuenta que los métodos de ...

Conservation Biology, Oct 1, 1995

Potato Diversity in the Andean Center of Crop Domestication STEPHEN BRUSH,* RICK KESSELI,f RAMIRO... more Potato Diversity in the Andean Center of Crop Domestication STEPHEN BRUSH,* RICK KESSELI,f RAMIRO ORTEGA,* PEDRO CISNEROS,§ KARL ... la conservación de germoplasma en cultivos amenazados por la erosión genética, teniendo en cuenta que los métodos de ...

Situ, 2000

This manual is intended for national programmes interested in supporting in situ conservation of ... more This manual is intended for national programmes interested in supporting in situ conservation of agricultural biodiversity maintained on-farm by farmers. It was written to provide a range of actors, including Ministries of Agriculture and the Environment, universities, research and extension institutions, non-government organizations (NGOs), and community based groups, with a comprehensive view of factors involved in designing and implementing a programme to support the in situ conservation of crop genetic ...

American Anthropologist, 1977

Journal of the Royal Anthropological Institute, 2016

Domestication, Evolution, and Sustainability, 2012

Some 15,000 to 10,000 years ago, humans started seeding and harvesting plants and maintaining ani... more Some 15,000 to 10,000 years ago, humans started seeding and harvesting plants and maintaining animals in order to augment the food they obtained from wild-growing plants and hunting. These seemingly simple activities set in motion a long-term process that has led to the dominance of agriculture as we know it today. With the exception of a few remaining hunter-gatherer groups, agriculture has now become the most important source of food for most people. Agriculture is also a major source of feed for animals and of fiber. This transition from hunting-gathering to agriculture was without a doubt one of the most significant eras in the evolution of humans. It allowed food production on a more intensive and efficient scale than ever before, eventually leading to population increases, labor specialization (and especially a nonagricultural sector), the formation of villages, cities, and states, and the rise of more hierarchical societies and states (MacNeish 1991, Barker 2006). The late Professor J. R. Harlan (1917-1998) understood that the complexity of the biological, societal, and environmental changes involved in the transition to agriculture, as well as their antiquity of up to 10,000 years, necessitated a multidisciplinary approach if one is to understand the factors and processes that have led to the "neolithic revolution." Anthropologists, archaeologists, climatologists, ethnobiologists, geneticists, geographers, linguists, physiologists, and other practitioners all contribute to the field of crop evolution studies. J. R. Harlan also expressed concerns that the very development and spread of improved crop varieties were leading to losses in crop biodiversity, well before concerns about biodiversity became common knowledge. He made clear how the knowledge of evolutionary processes in crops facilitated the conservation of biodiversity and its use in the development of improved crop varieties. The vision of Professor Harlan was the inspiration for the first Harlan Symposium, which took place in 1997 in Aleppo, Syria, at the International Center for Agricultural Research in the Dry Areas (ICARDA). That symposium was remarkable because it brought together plant scientists and archaeologists

The Journal of Environment & Development, 1996

Economic Botany, 1990

ISQzvme markers were u cd 10 Sllrw'Y Ih" gen"lIC mria!)/!llyofnon-blller pow/OC\ in 10 subsistenc... more ISQzvme markers were u cd 10 Sllrw'Y Ih" gen"lIC mria!)/!llyofnon-blller pow/OC\ in 10 subsistence./iRlds of Andeanfarmers al 3600-3850 In above sea level. Sixty Si'\"en percent oflhe "'{JnelJe.~ were /elrapfOtds corresponding 10 the 'pCClCX Solanum tuberosum ssp. andigcna, ! 4% Iv",rc /nplolds. probably corr;;spondllJg 10 /he speCies S. x ehaueha. and I JW) It'ere diploids corresponding 10 Ihc specics S. Slenotomum. S. phureja. and S gOD.ocalyx. The isozymc 111!ormall0I1 served to de/ermine Ihe consistency oflhe folk naming sySIi?m, We found a high degree ofcorrespondence bcllvecn farmer idcl1/1jicQIIO!1 and efectrophore/lc phenolypes. The consiSli!ncy 0/ Ihe ji)lk syslO:m In deurophoreric /errns depended on Ihe farmer who was In/ef l'icII'cd. The mosl common Incongruity COI1SISled ofcallmg dlj}erent deClrophor~lIc phUlo/ypes by Ihe sume \'(11'1('1.1' name. leadmg 10 a slighI undereslimation ofgenetIC I'anabilil\' /Jrcoenl ill Ihe jldds. The amount ofvaflabllity observed In the sample or Ihe Andean pOlalO poplila/lon was superIOr /0 Ihal present In /\lorl17 A mencan and l~'uropcan varieties, This was !neaswTd inlerrns ofnumbcr ofalleles, number 0/ elecrrophoreth phcnIJlypes and percelll of hcterozygosllY. This jmdlllg SUPPOriS Ihe impressiollihal () subslanlwf ([mOun I ofyel Ulu'Ap/olled vanabtllly r~matns in Ilndc()1I ,.•ola/o popl//alll)IlS. Evaluaeion bioqllllTl ica y popular de \<:1 variabilidad interespeeifica de las papas clIlti vadas en los Andes. Ell <'51,' traba}o se da a conoeer fos resultados de un estudlO f(CnCl;CO subrc '•aflcdadcs d(' papa dulce en los Andes, realuuda pOI' medlO de marcadarcs ISOenZ/I1UlliC/JS ell parcetas de subslstencia loca/izados entre 3600 y 3850 ,ilelros sobre e! nive! de! mar. 5e eneon/ra que 67% de {as variedades mues Ircadas ,':an IelraplOides de fa ('specie S. wberosum ssp, andigena, 14% Inpfoides probabfemell/e de fa espeCle S. x chaucha, y IJljlo dip/aides de las especles S. stenolOmllm, S. phureja und S. gonioealyx. La informaCion IsoenZimallca lue (Ill! en fa C'valuaCton de la /)I'e('lslon cle! sistema lolkforlco pam Idenllficar varu:dades. Sc ellcontro un allO grado dl! asoClaCion ('!/Ire ef 5ls/(,ma d'" etasljtcaclon usado POl' e! campesillo para deno/mllar sus \'ariedade~, J' los feno/lpos eleciroforell cos. La prCClsion del "t"lema de Ic//?Iltic/ad fofklorico en lermlnos dec/roforaicos dependlo del campeslI10 emrel'is/(jdo. La discrepanCia mas /recuen/(' entre los dos 5151('1'1'10$ de nomenclatura COnSlSlllJ en {{amar e/(ferenles jcnOI/pus c1eclroforc/icos con eI mislllo lIombre l•aTlelal. fo que rcsuflO cn una subesllinaCIi)n de la vartab/fldad gcnetico pre ('1/1(' ('II I(J~ campos. Ef I/II'eI de vanabIfldad observado en fa mueslro de PQfJQ.\ de la jJob!ac/lj" ane/ma Iu;; superior a/ ohsen'ado en ,'ariedades nortea II1crimnas.l' curopeas, La \'ariilliitidud .Ie midlo ell bose al mimcrode aldos, I1lfrnero dejenolipos eleclr%rellcos l' porcenlaje de heleroCigosidad. ESlos resultados es/an de ael/erdo COil la Impri?SI{)n general de que lodal'fa e-'oste mucha vanabllidad en rariedadcs de papa alldll1as que no ha sido alin explotada.

Human Organization

... Anne-Marie Ridgley received an MS in International Agricultural Developmentfiom the Universit... more ... Anne-Marie Ridgley received an MS in International Agricultural Developmentfiom the University of California, Davis (1991). ... 1980; Byerlee and Collinson 1980; Gladwin 1989; Rhoades 1987; Rhoades and Bebbington 1988; Shaner, Phillips and Schmehl 1982; Tripp 1985). ...

Human Ecology

This paper reconsiders two widely held hypotheses about the effects of the green revolution, that... more This paper reconsiders two widely held hypotheses about the effects of the green revolution, that it led to biological simplification and instability. The hypothesis of biological simplification (genetic erosion) is tested with evidence from Andean agriculture, where farmers maintain a significant degree of crop diversity even as the 3 , adopt modern crop varieties. The hypothesis of increased instability is tested with evidence from Asia where wheat and rice yields show no general pattern of increased instability. Neither of these hypotheses is confirmed. The conventional wisdom about the green revolution should be reconsidered with emphasis on resilience and variation in modernizing farming systems.