The Coevolution of Life and Arsenic in Precambrian Oceans (CLAPO)

Project leader

Funding source

European Research Council (ERC)

Project Details

Start date: 01/09/2013
End date: 31/08/2018
Funding: 1486374 EUR


The ubiquity of arsenic resistant genes across all of life's variety suggests a close intimacy between arsenic biogeochemistryand evolution, over geological time scales. However, the behaviour of arsenic in past environments where life originatedand its impact on our evolution is essentially unknown. Arsenic is of particular importance because of its toxic properties, prevalence in tight association with ubiquitous iron and sulfide minerals and as a major component of sulfide-rich waters, allcommon features of Precambrian oceans. Arsenic obstructs the synthesis of the building blocks of life, exhibiting both chronicand acute toxicity at very low concentrations. These properties make arsenic an agent capable of exerting strong selectivepressure on the distribution, success and diversity of life. This is exemplified by when the release of arsenic into groundwaterfollowing rock-weathering processes results in widespread poisoning. Using the state of the art stable isotopes tools, coupledto biomass production, bacterial iron, arsenic and sulfur cycling under ancient oceanic conditions, this project will open anew discussion on the much debated relationship between ocean chemistry and evolution, by introducing a new arsenicframework. This will be achieved under three majors themes:

1) Does there exist a biogeochemical connection betweenarsenic and the timing and transition from the iron-rich to the hypothesized sulfide-rich oceans that are linked to the rise ofatmospheric oxygen?

2) Does arsenic and sulfide show concomitant cyclicity during the Precambrian?

3) Could arsenic thusserve as a proxy for the calibration of key transitional steps in the timing of biological innovation?

Last updated on 2017-22-03 at 07:12