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Dear members- I encourage everyone to read both the starch manual and the New World publications that have been listed on this forum. Issues of potential contamination have been taken very seriously by Neotropical starch researchers for over a decade, and solutions were developed early on and have been addressed quite thoroughly in publications beginning with Piperno et. al. in Nature in 1998. All our procedures from initial excavation to the final laboratory analyses are designed to prevent contamination from modern starches as well as cross contamination from one tool to another. I also humbly suggest the following papers as resources, particularly the supplementary information sections in the Nature and Science papers and the methods in the LAA and JAS papers that detail methodologies. 2007 Perry, L. R. Dickau, S. Zarrillo, I. Holst, D. Pearsall, D. Piperno, M. Berman, R. Cooke, K. Rademaker, A. Ranere, J. Raymond, D. Sandweiss, F. Scaramelli, K. Tarble, and J. Zeidler. Starch fossils and the domestication and dispersal of chili peppers (Capsicum spp. L.) in the Americas. Science 315: 986-988. With accompanying Perspective, Knapp, S. Some Like it Hot. Science 315: 946-947. 2007 Perry, L. Starch grains, preservation biases, and plant histories. In Rethinking Agriculture: Archaeological and Ethnographic Perspectives. T. Denham , L. Vrydaghs and J. Iriarté (Eds.). One World Archaeology, Left Coast Press. 2006 Perry, L., D. Sandweiss, D. Piperno, K. Rademaker, M. Malpass, A. Umire, and P. de la Vera. Early Maize Agriculture and Interzonal Interaction in Southern Peru. Nature 440: 76-79. Featured author, "Making the Paper," same issue. 2005 Perry, L. Reassessing the Traditional Interpretation of “Manioc” Artifacts in the Orinoco Valley of Venezuela. Latin American Antiquity 16(4): 409-426. 2004 Perry, L. Starch analyses reveal the relationship between tool type and function: an example from the Orinoco valley of Venezuela. Journal of Archaeological Science 31(8): 1069-1081. 2002 Perry, L. Starch Granule Size and the Domestication of Manioc (Manihot esculenta) and Sweet Potato (Ipomoea batatas). Economic Botany 56(4): 335-349. Best wishes, Linda Perry ---------------------------------------- > Date: Fri, 7 Mar 2008 11:52:13 +0100 > From: [log in to unmask] > Subject: starch preservation > To: [log in to unmask] > > Dear members, > > The preservation of starch is complex, but also particularly > controversial. On the one hand researchers keep finding starch in > soils and on artefacts and on the other hand there is great scepticism > towards preservation. Unfortunately, the latter is as far as I know > not openly discussed in print. > > I included part of my (unpublished) thesis in which I discuss > preservation of starch. Special circumstances lead to preservation, > but I think that these are unique; as in for example desiccated > charred plant remains. Potentially there is an over representation of > starch due to contamination issues. Starch is incredibly abundant and > it is known that flowers mills (air borne starch), gloves with talcum > powder, starch from the analyst's lunch and starch in soils > contaminate tools. Contaminants from soil can adhere to a tool and > when analysts ignore the quantity and distribution of these grains > (for soil contaminants there will be only a few, which are randomly > dispersed) they can misinterpret the data. > > When reading the attachment, please keep in mind that this is only a > draft and it still requires polishing!! I thought it important for > this discussion to give a full overview, but it not necessarily the > best. Alternatively: Haslam, M. 2004. The decomposition of starch > grains in soils: implications for archaeological residue analyses. > Journal of Archaeological Science 31:1715-1734. > > I am keen to know if there are more sceptical papers on starch > research/preservation around and what the general attitude towards > starch preservation and analysis is. In addition, are there opinions > on the identification of starch grains to plant species level? > > Cheers, > Geeske Langejans > > > -- > G.H.J. Langejans > PhD Candidate > > University of the Witwatersrand > School of Geography, Archaeology and Environmental Studies > > Private bag 3, PO box WITS 2050, South Africa > > Telephone: +27 (0)11-717 6063 > Cell: +27 (0)76 569 0801 > Fax: +27 (0)11 717 6578 > Office address: Richard Ward Building, room 516, East Campus > > Telephone in the Netherlands: +31 (0)6 486 89 266 > > http://web.wits.ac.za/Academic/Science/Geography/FieldSchools/LimpopoRiverFieldSchool/Home.htm _________________________________________________________________ Climb to the top of the charts! Play the word scramble challenge with star power. http://club.live.com/star_shuffle.aspx?icid=starshuffle_wlmailtextlink_jan