@article {2472,
	title = {Documenting domestication in a lost crop (Polygonum erectum L.): evolutionary bet-hedgers under cultivation},
	journal = {Vegetation History and Archaeobotany},
	volume = {2621544151612277251256252491314471317501927512453130187936325211846611242525023108578256126282112},
	year = {2017},
	month = {Jan-05-2017},
	pages = {313 - 327},
	abstract = {This study uses morphometrics and digital image analysis to document domestication syndrome in an annual seed crop, Polygonum erectum L. (erect knotweed), which was cultivated by Native Americans for c. 2,500 years in eastern North America. This plant is one of several seed crops referred to as the Eastern Agricultural Complex, a pre-maize agricultural system that supported societies in a core area centred on the central Mississippi valley for millennia. The extinct domesticated subspecies P. erectum ssp. watsoniae N. G. Muell. described here, exhibits some classic markers of domestication, including larger fruits and reduced germination inhibitors in comparison to its wild progenitor. Domesticated P. erectum also exhibits greatly reduced germination heteromorphism. Germination heteromorphism is the classic example of evolutionary bet-hedging in plants: wild P. erectum sacrifices maximum fitness per generation for a reduction in fitness variance over many generations. It does so by producing two different types of fruits: ones that germinate immediately in the spring after they are produced (smooth morphs), and ones that remain in the soil seed bank for one or more growing seasons before germinating (tubercled morphs). Tubercled morphs allow populations to recover after adverse events. Under cultivation, the selective pressures that maintained this strategy were relaxed as humans saved seeds and created predictable microenvironments for seedlings, resulting in homogenous harvests and reliable germination for ancient farmers.},
	keywords = {Domestication, Eastern Agricultural Complex, Evolutionary bet-hedging, Morphometrics, Origins of agriculture},
	issn = {0939-6314},
	doi = {10.1007/s00334-016-0592-9},
	url = {http://link.springer.com/10.1007/s00334-016-0592-9http://link.springer.com/content/pdf/10.1007/s00334-016-0592-9.pdfhttp://link.springer.com/content/pdf/10.1007/s00334-016-0592-9.pdfhttp://link.springer.com/article/10.1007/s00334-016-0592-9/fulltext.html},
	author = {Mueller, Natalie G.}
}
@article {2471,
	title = {Evolutionary {\textquotedblleft}Bet-Hedgers{\textquotedblright} under Cultivation: Investigating the Domestication of Erect Knotweed (Polygonum erectum L.)~using Growth Experiments},
	journal = {Human Ecology},
	volume = {451072rspb2010070712131513581318177327257912425250103106757712621},
	year = {2017},
	month = {Jan-04-2017},
	pages = {189 - 203},
	abstract = {Evolutionary {\textquotedblleft}bet-hedging{\textquotedblright} refers to situations in which organisms sacrifice mean fitness for a reduction in fitness variance over time. Germination heteromorphism is the quintessential and most well understood bet-hedging strategy. It has evolved in many different plants, including the wild progenitors of some crops. Erect knotweed (Polygonum erectum L.), an annual seed crop, was cultivated in Eastern North America between c. 3000{\textendash}600 BP. By c. 900 BP, cultivation had produced a domesticated subspecies with greatly reduced germination heteromorphism. Field observations and greenhouse experiments suggest that cultivation eliminated the selective pressures that maintain the bet-hedging strategy in erect knotweed, while humans also directly selected for seeds that germinated reliably and for seedlings with rapid early growth. The protection provided to erect knotweed under cultivation explains the domestication syndrome that has been observed in some archaeological assemblages. Dormancy provides seeds a means of escaping adverse conditions in time, while dispersal provides an escape in space. Farmers relaxed selective pressures that maintained dormancy in erect knotweed by acting as seed dispersers, spreading disturbance-adapted plants to predictable and protected environments, and by saving and exchanging seed stock. Experimental data also indicate that adaptive transgenerational plasticity may have been working against the expression of domestication syndrome in this case.},
	keywords = {Domestication, Eastern agricultural complex North America, Erect knotweed, Evolutionary bet-hedging, Experimental archaeology},
	issn = {0300-7839},
	doi = {10.1007/s10745-016-9881-2},
	url = {http://link.springer.com/10.1007/s10745-016-9881-2http://link.springer.com/content/pdf/10.1007/s10745-016-9881-2.pdfhttp://link.springer.com/content/pdf/10.1007/s10745-016-9881-2.pdfhttp://link.springer.com/article/10.1007/s10745-016-9881-2/fulltext.html},
	author = {Mueller, Natalie G.}
}
@article {2473,
	title = {An Extinct Domesticated Subspecies of Erect Knotweed in Eastern North America: <i>Polygonum erectum</i>               subsp. <i>watsoniae</i>               (Polygonaceae)},
	journal = {Novon: A Journal for Botanical Nomenclature},
	volume = {25},
	year = {2017},
	month = {Jan-04-2018},
	pages = {166 - 179},
	abstract = {This paper provides a description of an extinct domesticated subspecies of erect knotweed (Polygonum erectum L.). Masses of erect knotweed achenes are often recovered from archaeological sites in eastern North America dating to ca. 3000{\textendash}600 BP. Several paleoethnobotanical assemblages from the later part of this era (ca. 1000{\textendash}600 BP) contain achenes that are outside the range of natural variation for erect knotweed. The most well preserved of these archaeological assemblages, a desiccated cache of achenes from the Whitney Bluff site, Arkansas (ca. 900 BP), is compared to four closely related species and subspecies of Polygonum L. The Whitney Bluff achenes are most similar to those of P. erectum, but differ from modern fruits of this species in three respects: (1) fruits are larger, (2) average pericarp thickness is reduced, and (3) fruit dimorphism is greatly reduced. These differences are typical of domestication syndrome in annual seed crops. The Whitney Bluff assemblage is described as the type specimen of a domesticated subspecies, P. erectum subsp. watsoniae N. G. Muell.},
	keywords = {Domestication, Eastern Agricultural Complex, fruit morphology, paleoethnobotany, Polygonum},
	issn = {1055-3177},
	doi = {10.3417/2016005},
	url = {http://www.bioone.org/doi/10.3417/2016005http://www.bioone.org/doi/full-xml/10.3417/2016005},
	author = {Mueller, Natalie G.}
}
