Previous Research

Our study on archaeal lipid biomarkers in terrestrial hydrothermal springs suggests that the production of crenarchaeol, a unique archaeal lipid, is favorable in moderate environmental conditions, such as mesophilic temperature and circumneutral pH. This supports a previous hypothesis that crenarchaeol may have facilitated the past evolutionary transition of archaea from hot springs into the marine realm. Click here for the BioRxiv preprint.  

We also find that pH is the most important environmental predictor of Ring Index, a summary indicator of the number of cyclopentyl rings in the membranes of hot spring archaea that produce GDGTs (glycerol dibiphytanyl glycerol tetraethers). This finding has important implications for the appropriate application of the TEX86 temperature proxy for reconstructing past Earth surface temperatures. 

Previous work on archaeal lipid carbon isotope ratios indicate that these values may be used to reconstruct past atmospheric CO2 concentrations, which is a vital endeavor to understand past and future climate change. Our study is the first environmental application of this potential carbon dioxide GDGT (glycerol dibiphytanyl glycerol tetraether) proxy after laboratory and model calibrations. Our results suggest that a multitude of environmental factors complicate the use of this proxy in the environment. Better constrained sites should be targeted for environmental testing or additional laboratory work should be conducted to understand the different factors that affect GDGT carbon isotope ratios. Click here for the presentation abstract from the 2022 Goldschmidt Conference.

Paleo-CO2.org