Early life

The origins and early evolution of life are key events in Earth history, and are topics on which only fossils can provide direct evidence. The earliest putative fossils date from 3,400 million years ago, and shortly after this, there is the widespread appearance of structures called stromatolites in the fossil record. These layered biosedimentary features, often reflect the presence of bacterial mats, and as such are of key importance to understanding the early history of life. Their chemistry can provide clues as to the metabolism of the organisms that formed them may have had.

ICAL members investigate early life using two primary approaches. Advanced imaging techniques allow us to study at the morphology of putative early cellular fossils, all the way back to 3.4 Ga. We have applied them to a range of fossil deposits older than 600 million years, as well as the earliest multicellular organisms, and those with hard parts. Members of the centre also use analytical techniques to probe the chemistry of stromatolites - both extant, and extinct. To do this, they use Synchrotron Rapid-Scanning X-ray Fluorescence (SRS-XRF), Fourier Transform Infrared Spectroscopy (FTIR), Extended X-ray Absorption Fine Structure (EXAFS) and Pyrolysis Gas Chromatography Mass Spectrometry (Py-GCMS) to study both the inorganic, and organic remnants of the organisms that formed the structures. Both approaches are allowing ICAL researchers to identify ancient life, and associated structures, with increasing confidence.

Lead researchers

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