Project EARTH-17-ES2: Biodiversity responses to mass extinction events: studying rates of niche evolution through time

Supervisors: Erin E. Saupe, Oxford, Earth Sciences

Earth’s climate is rapidly changing, altering all facets of our planet at an unprecedented rate, from the biosphere to the hydrosphere to the atmosphere (Barnosky et al. 2011). Given these changes, there is debate as to whether species can adapt their physiological tolerances, or niches, sufficiently quickly to survive rapid environmental change (Lavergne et al. 2010). Importantly, the relative frequency and tempo of niche evolution is the explicit purview of palaeobiology, since a temporal perspective is needed for any such analysis (Saupe et al. 2014).

No study, however, has quantified rates of niche evolution across the Phanerozoic, even though this information is vital for implementing proper conservation measures, mitigating threats posed to biodiversity, and shedding light on macroevolutionary dynamics. The DPhil student will, for the first time, quantitatively test: (1) The relative frequency and rate of within-lineage niche evolution during background and mass extinction intervals; (2) Whether the rate of niche evolution accelerates during mass extinction events relative to background times; and (3) Whether rates of niche evolution correlate with rates of environmental change, and how this relationship varies between mass extinction events and background intervals.

To test these hypotheses, the student will marshal a robust spatially- and temporally-explicit database of Phanerozoic bivalve fossils in the orders Arcida, Carditida, and Ostreida, which together constitute ~50% of extant marine bivalve species. These orders represent excellent model clades because they have a high preservational potential, which has provided well-resolved spatial and temporal data through time, and they have been subject to extensive taxonomic research, which has ensured these data are well-represented in museum collections and online databases. Using this spatial and temporal database of marine bivalves, the student will construct estimates of species’ abiotic niches using ecological modelling coupled with state-of-the-art global climate model data for each interval within a species’ lifetime. These niche models will then be used to generate estimates of the amount of change that has occurred over time using a number of cutting-edge, multidimensional analytical techniques.

The project will represent a significant contribution to our understanding of the long-term dynamics of niche evolution, and results will be important for improving our predictions of how species will respond to present-day and future environmental changes. The student will be provided with state-of-the-art training in ecological modelling, database construction, global climate modelling, and Geographic Information Systems (GIS). More general guidance on technical writing, public speaking and teaching will be offered. This combination of specialist research competencies and generic transferable skills will make the student well suited for a range of high-profile positions within the scientific community. The student will have the opportunity to travel abroad to collect data, and to present results at major, international conferences (e.g. AGU, GSA, PalAss).

Further Reading:

Barnosky, A. D. et al. Has the Earth’s sixth mass extinction already arrived? Nature 471, 51–57 (2011).

Lavergne, S., Mouquet, N., Thuiller, W. & Ronce, O. Biodiversity and climate change: integrating evolutionary and ecological responses of species and communities. Annu. Rev. Ecol. Evol. Syst. 41, 321–350 (2010).

Saupe, E. E. et al. Macroevolutionary consequences of profound climate change on niche evolution in marine molluscs over the past three million years. Proceedings of the Royal Society of London B: Biological Sciences 281(1795), 20141995 (2014).