Origins and evolution of ancient Egyptian cotton tracked by palaeogenomics

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This study aims to answer several questions about cotton genome evolution and domestication utilizing remarkably preserved archaeobotanical samples from Qasr Ibrim in Egypt and Januária in Brazil. The new technology of palaeogenomics - the study of genomes in the past through direct observation of their ancient DNA (Poinar et al 2006) - enables these questions to be addressed in a completely new way. The aims are threefold: Firstly, to identify the cotton species present in ancient Egypt and Januária in order to evaluate archaeological hypotheses. This will be achieved through the species identification of archaeobotanical cotton - currently not possible through visual examination. Different species of cotton are associated with different cultural groups, so identification will lead to inferences about whhich cultures of the past influenced early cotton cultivation. Secondly, to add an extra dimension to the study of cotton genome evolution to address several hypotheses of genomic change over the past three thousand years. The whole genus of cotton has experienced genomic expansion, and there is some evidence that this process is ongoing. The paleogenomic approach will allow an assessment of the extent of change there has been over the past three thousand years. Thirdly, to establish the applicability of this new technology to the mummified archaeobotanical remains from Qasr Ibrim and Januária. There are large quantities of archaeobotanical material at these sites which could become an invaluable genetic resource for our understanding of the evolutionary changes that occurred during the domestication and cultivation processes.