Domestication of Capsicum annuum chile pepper provides insights into crop origin and evolutionJune 22, 2009Without the process of domestication, humans would still be hunters and gatherers, and modern civilization would look very different. Fortunately, for all of us who do not relish the thought of spending our days searching for nuts and berries, early civilizations successfully cultivated many species of animals and plants found in their surroundings. Current studies of the domestication of various species provide a fascinating glimpse into the past. A recent article by Dr. Seung-Chul Kim and colleagues in the June 2009 issue of the American Journal of Botany explores the domestication of chiles. These hot peppers, found in everything from hot chocolate to salsa, have long played an important role in the diets of Mesoamerican people, possibly since as early as ~8000 B.C. Capsicum annuum is one of five domesticated species of chiles and is notable as one of the primary components, along with maize, of the diet of Mesoamerican peoples. However, little has been known regarding the original location of domestication of C. annuum, the number of times it was domesticated, and the genetic diversity present in wild relatives. To answer these questions, Dr. Kim and his team examined DNA sequence variation and patterns at three nuclear loci in a broad selection of semiwild and domesticated individuals. Dr. Kim et al. found a large amount of diversity in individuals from the Yucatan Peninsula, making this a center of diversity for chiles and possibly a location of C. annuum domestication. Previously, the eastern part of central Mexico had been considered to be the primary center of domestication of C. annuum. On the basis of patterns in the sequence data, Dr. Kim et al. hypothesize that chiles were independently domesticated several times from geographically distant wild progenitors by different prehistoric cultures in Mexico, in contrast to maize and beans which appear to have been domesticated only once. Geographical separation among cultivated populations was reflected in DNA sequence variation. This separation suggests that seed exchange among farmers from distant locations is not significantly influencing genetic diversity, in contrast to maize and beans seeds, which are traded by farmers across long distances. Less genetic diversification was seen in wild populations of C. annuum from distant locales, perhaps as a result of long-distance seed dispersal by birds and mammals. Across the three loci studied, Dr. Kim and colleagues found an average reduction in diversity of 10% in domesticated individuals compared with the semiwild individuals. Domesticated chiles in traditional agricultural habits, however, harbor unique gene pools and serve as important reservoirs of genetic diversity important for conserving biodiversity. American Journal of Botany |
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| Related Domestication Current Events and Domestication News Articles First draft of the pig: Researchers sequence swine genome A global collaborative has produced a first draft of the genome of a domesticated pig, an achievement that will lead to insights in agriculture, medicine, conservation and evolution. The amazing maze of maize evolution Understanding the evolution and domestication of maize has been a holy grail for many researchers. As one of the most important crops worldwide and as a crop that appears very different from its wild relatives as a result of domestication, understanding exactly how maize has evolved has many practical benefits and may help to improve crop yields. Milk drinking started around 7,500 years ago in central Europe The ability to digest the milk sugar lactose first evolved in dairy farming communities in central Europe, not in more northern groups as was previously thought, finds a new study led by UCL (University College London) scientists published in the journal PLoS Computational Biology. African village dogs are genetically much more diverse than modern breeds African village dogs are not a mixture of modern breeds but have directly descended from an ancestral pool of indigenous dogs, according to a Cornell-led genetic analysis of hundreds of semi-feral African village dogs. Human-dog communication -- breed as important as species Dog breeds selected to work in visual contact with humans, such as sheep dogs and gun dogs, are better able to comprehend a pointing gesture than those breeds that usually work without direct supervision. Notre Dame study describes evidence of world's oldest known granaries A new study coauthored by Ian Kuijt, associate professor of anthropology at the University of Notre Dame, describes recent excavations in Jordan that reveal evidence of the world's oldest know granaries. A Genome May Reduce Your Carbon Footprint With the costs of genome sequencing rapidly decreasing, and with the infrastructure now developed for almost anyone with access to a computer to cheaply store, access, and analyze sequence information, emphasis is increasingly being placed on ways to apply genome data to real world problems, including reducing dependency on fossil fuel. 3-year-olds get the point Dogs and small children who share similar social environments appear to understand human gestures in comparable ways. Wild grass became maize crop more than 8,700 years ago The earliest physical evidence for domesticated maize, what some cultures call corn, dates to at least 8,700 calendar years ago, and it was probably domesticated by indigenous peoples in the lowland areas of southwestern Mexico, not the highland areas. Early agriculture left traces in animal bones Unraveling the origins of agriculture in different regions around the globe has been a challenge for archeologists. Now researchers writing in the Proceedings of the National Academy of Sciences report finding evidence of early human experiments with grain cultivation in East Asia. They gathered this information from an unlikely source―dog and pig bones. More Domestication Current Events and Domestication News Articles |
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