Research Theme 5 – Combination of Life-Essential Elements

Most current scenarios for the origin of life assume that the first steps involved incorporation of organic compounds from the environment into prebiotic structures and protometabolic processes. Along with delivery of organic matter from comets and meteorites, this production was likely a major source of compounds available for the emergence of life. Following planetary formation and crystallization of the magma ocean, the life-essential elements are likely to be present in the rocky mantle predominantly as inorganic species (i.e., CO₂, CO, N₂, NH₃, H₂S, PO₄, etc.) or simple organic compounds (e.g., CH₄, HCN, dimethylsulfide). Continued progress from these simple precursors towards an origin of life would require that they be converted into organic compounds that could participate the early stages of chemical evolution.

Volcanic hydrothermal systems represent a primary conduit for the transfer of life-essential elements from the interior of a planet to the surface. Thermodynamic factors may be able to convert inorganic compounds or simple organic precursors that were likely formed during planetary formation and differentiation (such as carbon dioxide, ammonia, and methane) into a variety of complex organic compounds relevant to prebiotic chemistry.

This final theme of research investigates the following questions:

1. Can volcanic hydrothermal environments convert simple precursors emerging from the mantle into organic compounds of prebiotic significance?

2. How does variation in the relative abundance and speciation of simple precursors emerging from the mantle affect the types and relative proportions of organic compounds that are produced?

The plan is to use laboratory experiments to investigate the conversion of simple precursors emerging from the mantle to organic compounds of prebiotic significance in volcanic hydrothermal environments. In this work, the focus will thus be on investigating how variation in the relative abundance and speciation of simple precursors emerging from the mantle affects the types and relative proportions of organic compounds that are produced. To investigate detectability of abiotic formation signatures of organics in geologic samples, fractionation of C, N, and S isotopes during these processes will also be measured.