Morphology of Orbulina universa and Globorotalia scitula across local extinctions during Sapropel S5 (Eastern Mediterranean Sea, c.126-121 ka) ...

• Main Authors: Weinkauf, Manuel F G, Moller, Tobias F, Koch, Mirjam C, Kucera, Michal
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 2014
• Subjects: Center for Marine Environmental Sciences MARUM; Planktonic foraminifera
• Online Access: https://dx.doi.org/10.1594/pangaea.832132; https://doi.pangaea.de/10.1594/PANGAEA.832132

Extinction is a remarkably difficult phenomenon to study under natural conditions. This is because the outcome of stress exposure and associated fitness reduction is not known until the extinction occurs and it remains unclear whether there is any phenotypic reaction of the exposed population that can be used to predict its fate. Here we take advantage of the fossil record, where the ecological outcome of stress exposure is known. Specifically, we analyze shell morphology of planktonic Foraminifera in sediment samples from the Mediterranean, during an interval preceding local extinctions. In two species representing different plankton habitats, we observe shifts in trait state and decrease in variance in association with non-terminal stress, indicating stabilizing selection. At terminal stress levels, immediately before extinction, we observe increased growth asymmetry and trait variance, indicating disruptive selection and bet-hedging. The pre-extinction populations of both species show a combination of ... : Supplement to: Weinkauf, Manuel F G; Moller, Tobias F; Koch, Mirjam C; Kucera, Michal (2014): Disruptive selection and bet-hedging in planktonic Foraminifera: shell morphology as predictor of extinctions. Frontiers in Ecology and Evolution, 2 ...