Origins and evolution of ancient Egyptian cotton tracked by palaeogenomics

这项研究的目的是利用来自埃及Qasr Ibrim和巴西Januária的保存完好的考古植物学样本来回答有关棉花基因组进化和驯化的几个问题。古基因组学的新技术--通过直接观察古DNA来研究过去的基因组（Poinar et al 2006）--使这些问题能够以一种全新的方式得到解决。目的有三：首先，确定古埃及和Januária的棉花品种，以评估考古假设。这将通过古植物棉花的物种鉴定来实现-目前无法通过目视检查。不同种类的棉花与不同的文化群体有关，因此，识别将导致关于过去的文化影响早期棉花种植的推断。第二，为棉花基因组进化的研究增加一个额外的维度，以解决过去三千年来基因组变化的几个假设。整个棉花属都经历了基因组扩增，有证据表明这一过程正在进行中。古基因组学方法将允许对过去三千年来的变化程度进行评估。第三，确定这项新技术对Qasr Ibrim和Januária的木乃伊化考古植物学遗骸的适用性。在这些遗址中有大量的考古植物材料，这些材料可能成为我们了解驯化和栽培过程中发生的进化变化的宝贵遗传资源。

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.