Helianthus annuus L http www uapress arizona edu onlinebks weeds sunflowr htm http www artchive com artchive g gauguin vangogh jpg http www artquotes net masters vangogh vangogh sunflowers1888 jpg http www 1st art gallery com artists vincent van gogh van goghs1 jpg http www art com asp sp asp pd 10106228 sp A Sunflowers htm http www larose com Cups and Mugs images Sunflowers Van Gogh JPG http static flickr com 23 374 69881 9ac0e3d549 m jpg http www abundantlifeseeds com s tores 1 Russian Mammoth P163C106 c fm UserID 5542 jsessionid 8c30a4fa decd FE DB 7 Domestication Competing Theories Mexican Hypothesis Lentz et al 2001 Archaeological evidence San Andr s Tabasco Mexico Dated to 4130 40 B P seed and 4085 50 B P achene Size well within range of domesticated sunflower seeds Eastern North American Hypothesis Crites 1993 Archaeological evidence 6 completely carbonized sunflower seeds 4265 60 years B P Hayes site Tennessee U S A Size length increased by 30 width by 45 5 7 mm x 2 2 mm 7 3 mm x 3 3 mm 6 7 mm x 2 9 mm 6 9 mm x 2 9 mm 7 3 mm x 2 9 mm 7 4 mm x 3 8 mm cutoff for domestication is between 5 and 7 mm Problems with Mexican Hypothesis Smith 2006 From Smith 2006 Problems with Mexican Hypothesis Smith 2006 No documentation that San Andr s seed is Helianthus annuus San Andr s achene lacks striations indicative of H annuus San Andr s is outside of current wild range From Smith 2006 Genetic Data Harter et al 2004 Defined two population clusters groups with distinct allelle frequencies 18 microsatellite loci Mexico Arizona Central US 10 runs of algorithm assigned domesticates to US After subdividing US cluster all domesticates assigned to easternmost populations from Harter et al 2004 from Harter et al 2004 from Harter et al 2004 Questions Algorithm Site 20 Oklahoma More genetic data Wills and Burke 2006 chloroplast DNA suggests single origin of domesticated sunflower in U S Liu and Burke 2006 nucleotide diversity confirms single origin of domesticated sunflower cannot determine location of event Liu and Burke 2006 cont Something I wish had been addressed from Harter et al 2004 Liu and Burke 2006 only published a phylogeny including Native American land races Gene flow is easy Snow et al 1998 and cited refs and it affects the behavior of wild plants Snow et al 2003 How should one deal with gene flow between crops and wild relatives At what point will gene flow obscure any phylogenetic signal Literature Cited Crites G D 1993 Domesticated sunflower in fifth millennium B P Temporal Context New evidence from Middle Tennessee American Antiquity 58 146 148 Harter A V K A Gardner D Falush D L Lentz R A Bye L H Rieseberg 2004 Origin of extant domesticated sunflowers in eastern North America Nature 430 201 205 Lentz D L M E D Pohl K O Pope A R Wyatt 2001 Prehistoric Sunflower Helianthus annuus L Domestication in Mexico Economic Botany 55 370 376 Rieseberg L H A V Harter 2006 Molecular evidence and the evolutionary history of the domesticated sunflower In Motley T N Zerega H Cross eds Darwin s Harvest New Approaches to the Origins Evolution and Conservation of Crops Columbia University Press Smith B D 2006 Eastern North America as an independent center of plant domestication Proceedings of the National Academy of Sciences U S A 103 12223 12228 Snow A A P Moran Palma L H Rieseberg A Wszelaki G J Seiler 1998 Fecundity phenology and seed dormancy of F1 Wild Crop Hybrids in Sunflower Helianthus annuus Asteraceae American Journal of Botany 85 794 801 Snow A A D Pilson L H Rieseberg M J Paulsen N Pleskac M R Reagon D E Wolf S M Selbo 2003 A Bt transgene reduced herbivory and enhances fecundity in wild sunflowers Ecological Applications 13 279 286 Wills D M J M Burke 2006 Chloroplast DNA variation confirms a single origin of domesticated sunflower Helianthus annuus L Journal of Heredity 97 403 408
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