Strack, Anne

Rates of adaptation to environmental change extracted from the fossil record of marine plankton

Over the last 600 ka, Earth’s climate is dominated by changes in the orbital geometry (eccentricity) causing glacial-interglacial cycles with a frequency of approximately 100 ka. These cycles are asymmetrical meaning long glacial periods are followed by rapid warmings. During these transitions – also referred to as deglaciations – the global climate is rapidly changing on a multi-millennial-scale which makes these time periods ideal to study potential adaptation to environmental change.

Marine plankton are of fundamental importance when it comes to the understanding of the pace and impacts that climate change will have on this planet. There are not only several feedback mechanisms which highlight the ability of marine plankton to contribute to global climate, but marine plankton are also very good indicators for climate change itself. They often have short live cycles and show a high evolutionary divergence; thus, it appears that plankton dynamics may be tightly coupled to environmental change. Also, marine plankton – by its definition – is free floating, so environmental change might be recorded by plankton distribution changes and shifts in their geographical range.

A basic goal of the present PhD project is to benefit from the vast amount of plankton assemblage data that have been published in environmental data archives such as PANGAEA and NCEI and to utilize these data to better understand the variability in natural time scales. In particular, this PhD project aims to spatially and temporarily investigate the rates of adaptation of marine plankton to environmental change. For that, assemblage as well as morphological data extracted from the fossil record will be analysed.

During this PhD project the biotic as well as morphological response of marine plankton to the last and the penultimate deglaciation will be analysed. Since the nature of biodiversity change is still not well understood, this PhD project also aims to investigate patterns of biodiversity changes of phyto- against zooplankton and their correlation at times of climate change and no or only subtle change. Furthermore, the predictability of the reaction of specific plankton groups to climate forcing across several glacial cycles will be analysed.