"Determining what is and what is not life in Earth’s oldest rocks, and identifying what type of life was present in these environments are fundamental scientific problems. Resolving these questions is vital in order to understand the origin of life on Earth, the role biology played in shaping early Earth environments, the nature and timing of evolutionary transitions, and to evaluate potential extra-terrestrial life. The timing and nature of the earliest life on Earth can only readily be addressed using fossil data, but these data are at present often the subject of controversy since they are difficult to interpret and there are few established criteria on which to interpret them. We effectively lack a coherent understanding of the evidence for the appearance of the major evolutionary grades of life on Earth. This proposal aims to remedy this and, in so doing, establish a gold standard for evaluating evidence of life on other planets.My overall objective is to develop and refine new ways of extracting information from remarkably preserved Precambrian organic material and the minerals that host it. This research will be focussed towards two aims: AIM 1 – provide new and more robust data to determine the authenticity of putative Precambrian life; AIM 2 – determine the type and diversity of life present in key Precambrian fossil assemblages. Specifically, this research will help to address some important outstanding questions in Precambrian paleobiology, including (i) evidence for the earliest cellular life, (ii) evidence for the nature of early diverse microfossil assemblages including the origin of eukaryotes, and (iii) evidence for the nature of early terrestrial biotas. More generally, the data generated will lead to a greater understanding of the origin and evolution of life, plus patterns of carbon preservation and burial through the Precambrian that influenced global biogeochemical cycles and climate change."