Abstract The Paleoproterozoic (2.5–1.6 Ga) Era is a decisive time in Earth and life history.
The paleobiological record (microfossils, stromatolites, biomarkers and isotopes) illustrates …

Nitrogen isotope compositions in sedimentary rocks (d 15 N sed) are routinely used for
reconstructing Cenozoic N-biogeochemical cycling and are also being increasingly applied …

Marine planktonic cyanobacteria contributed to the widespread oxygenation of the oceans
towards the end of the Pre-Cambrian and their evolutionary origin represents a key …

It is often acknowledged that the search for life on Mars might produce false positive results,
particularly via the detection of objects, patterns or substances that resemble the products of …

New analytical approaches and discoveries are demanding fresh thinking about the early
fossil record. The 1.88-Ga Gunflint chert provides an important benchmark for the analysis of …

The recognition of past habitable environments on Mars has increased the urgency to
understand biosignature preservation in and characterize analogues of these environments …

Life on Earth has existed for at least 3.5 billion years. Yet, relatively little is known of its
evolution during the first two billion years, due to the scarceness and generally poor …

The deep biosphere is one of the least understood ecosystems on Earth. Although most
microbiological studies in this system have focused on prokaryotes and neglected …

Phosphorus is a nutrient fundamental to life and when it precipitates in modern
environments bacteria are intimately involved in its release, concentration, and …

High precision analyses of all four sulfur isotopes in four pyrite and three sphalerite
standards and in working reference samples were carried out using a CAMECA NanoSIMS …