I am fascinated by the jigsaw of complex interactions between the evolution of organisms, ocean chemistry, atmospheric composition and Earth’s climate. The extraction of chemical signatures from fossil shells of marine micro-organisms as a tool for constraining past ocean conditions and their influence on climate is fundamental to my research. Yet frustration with the complexities of disentangling the “inorganic” geochemical signal from the overprint of the biomineralising processes has triggered me to seek innovative alternative approaches to constraining past climates and environments. Increasingly I am probing the geological past from the biology of modern day organisms. This ambition broadens into probing biological innovation and environmental change over Earth history since the feedback between the two is inescapable. All modern day organisms have experienced a long evolutionary pathway to arrive at their present incarnation and this history has been accrued to some extent within the genome and physiology of modern day organisms. Indeed such evolutionary history influences the tolerance of different algae to ocean acidification for example, or the trace metal nutrient requirements of different groups of algae across the tree of life. So my approach is to read the geological history of both climate and the chemical environment from signals of adaptation within genes, which plays out in the evolving affinity and kinetics of the expressed enzymes, or isotopic signals of adaptation within biologically relevant molecules.
I lead the OceanBUG research group and my quest for a new proxy based on biological understanding of the signal is reflected in our current projects which include:
Species-specific coccolithophore response to ocean acidification
Lifting the CAP on coccolithophore calcification: characterising acidic polysaccharides which mould the calcite liths of coccolithophores as probes of the past carbon environment
Squelching into the fine mud: dissecting the fine fractions of sediments to read the physiological controls on the isotopes of both coccoliths and diatoms
Characterisation of modern and ancient algal Rubisco with implications for carbon isotopes and acquisition
I spoke about aspects of my work as part of the Royal Society’s Science Stories series:
Most recently we were involved in an interdisciplinary exhibit at the Royal Society Summer Science Exhibition celebrating 150 years of the Periodic Table and what it means for life on earth. Follow the link for more information and a chemical crossword!
View Selected Publications
- Invention of tools to unearth records of physiology and adaptation
*Rickaby, R. E. M., J. Henderiks, and J. N. Young, Perturbing phytoplankton: response and isotopic fractionation with changing carbonate chemistry in two coccolithophore species, Clim. Past, 6, 771-785, 2010
*McClelland H. L. O., J. Bruggeman, M. Hermoso & R. E. M. Rickaby, The origin of carbon isotope vital effects in coccolith calcite, Nat Comms, DOI: 10.1038/ncomms14511, 2017
*Lee, R. B. Y., Mavridou, D., Papdakos,G., McLelland, H. L. O., and R. E. M. Rickaby, The Uronic acid content of coccolith associated polysaccharide provides insights into evolving coccolithogenesis and climate, Nat. Comms, doi:10.1038/ncomms13144, 2016.
*Rickaby, R. E. M., D. P. Schrag, U. Riebesell, & I. Zondervan, Growth-rate dependence of Sr incorporation during calcification of Emiliania huxleyi, Global Biogeochem. Cycles, 16 (1), 2001GB001408, 2002.
*Young, J. N., Rickaby, R. E. M., Kapralov, M., and Filatov, D., Adaptive Signals in Algal Rubisco Reveal a History of Ancient Atmospheric CO2, Philosophical Transactions of the Royal Society, 367, 483-492, 2012.
*Young, J. N., Heureux. A., Sharwood, R., Rickaby, R. E. M., and Whitney, S. M., The variation in diatom Rubisco kinetics reveals diversity in the efficiency of their carbon concentrating mechanisms. J. Exp. Bot. doi: 10.1093/jxb/erw1632016, 2016 (featured in 2050 Thinking for Plant Science: https://www.sebiology.org/news/article/2016/07/12/2050-thinking-for-plant-science; and commentary by Hanson, D. T., Breaking the rules of Rubisco catalysis, J. Exp. Bot., 67, 3180-3182, 2016)
- The backdrop to the birthday of the coccolithophores
*Korte, C. S. P. Hesselbo, H. C Jenkyns, R. E. M. Rickaby and C. Spotl, Palaeoenvironmental significance of carbon- and oxygen-isotope stratigraphy of marine Triassic–Jurassic boundary sections in SW Britain, Journal of Geological Society of London, 166, 431-445, 2009.
*Lu, Z., H. C Jenkyns, R. E. M. Rickaby, I/Ca ratios in marine carbonate as a palaeo-redox proxy during oceanic anoxic events, Geology, 38, 1107-1110, 2010.
*Lu, W., A. Ridgwell, E. Thomas, D.S Hardisty, G. Luo, T. J Algeo, M. R Saltzman, B. C Gill, Y. Shen, H.Ling, C.T. Edwards, M. T. Whalen, X. Zhou, K.M. Gutchess, L. Jin, R.E.M. Rickaby, H. C. Jenkyns, T. W. Lyons, T.M. Lenton, L. R. Kump, Z. Lu, Late inception of a persistently oxygenated upper ocean, Science, eaar5372, 2018, DOI: 10.1126/science.aar5372
(This paper arose directly from paper 56 above, the first to suggest the use of I/Ca as a proxy for palaeo-redox state.)
* R. E. M., M. R. E. Hubbard, Upper ocean oxygenation, evolution of RuBisCO and the Phanerozoic succession of phytoplankton, Free Radical Biology and Medicine, 140, 295-304, 2019 (recommended in F1000prime)
*Monteiro, F. M., L. T. Bach, C. Brownlee, P. Bown, R. E. M., Rickaby, T. Tyrrell, L. Beaufort, S. Dutkiewicz, S. Gibbs, M. Gutowska, R. B. Y. Lee, A. Poulton, U. Riebesell, J. Young, A. Ridgwell, Why marine phytoplankton Calcify? Science Advances, 2 (7) e1501822, 2016
- Evolution of Coccolithophores and the Carbon Cycle
*Rickaby R. E. M., E. Bard, C. Sonzogni, F. Rostek, L. Beaufort, S. Barker, G. Rees. and D. P. Schrag, Coccolith chemistry reveals secular variations in the global ocean carbon cycle? Earth Planet. Sci. Letts. 253, 83-95, 2007.
*Bendif, E. M., B. Nevado, E. Wong, K. Hagino, I. Probert, J. R. Young, R. E. M. Rickaby and D. A. Filatov, Repeated species radiations in the recent evolution of Gephyrocapsa species, Nature Communications, 10, 4234, 2019
*Bard E., and R. E. M. Rickaby Migration of the subtropical front as a modulator of glacial climate, Nature, 460, 380-383, 2009
*Iglesias-Rodriguez, M. D., P. R. Halloran, R. E. M. Rickaby, I. R. Hall, E. Colmenero-Hidalgo, J. R.Gittins, D. R.H. Green, T. Tyrrell, S. J. Gibbs, P. von Dassow, E. Rehm, E. V. Armbrust and K.P. Boessenkool, Phytoplankton calcification in a high CO2 world, Science, 320, 336-340, 2008
*Winter A., J. Henderiks, L. Beaufort, R. E. M. Rickaby, C. W. Brown, Poleward expansion of the coccolithophore Emiliania huxleyi, Journal of Plankton Research, 36, 316-325, 2014
- Coevolving metalloenzymes and the environment
*Elderfield, H., & R. E. M. Rickaby, Oceanic Cd/P ratio and nutrient utilisation in the glacial Southern Ocean, Nature, 405, 305-310, 2000
*Horner, T. J., R. B. Y. Lee, G. M. Henderson, R. E. M. Rickaby, Unavoidable uptake and homeostasis drives the oceanic cadmium cycle, PNAS, 110, 2500-2505, 2013
*Williams, R. J. P., and Rickaby R. E. M., Evolution’s Destiny: Co-evolving Chemistry of the Environment and Life, Publisher: Royal Society of Chemistry, 20th July 2012, 336 pages.
*Shafiee, R. T., J..T. Snow, Q. Zhang, R. E. M. Rickaby, Iron requirements and uptake strategies of the globally abundant marine ammonia-oxidising archaeon, Nitrosopumilus maritimus SCM1, The ISME journal, 13, 2295–2305, 2019