A SHIFT IN THE LONG-TERM MODE OF FORAMINIFERAN SIZE EVOLUTION CAUSED BY THE END-PERMIAN MASS EXTINCTION

摘要: Size is among the most important traits of any organism, yet factors that control its evolution remain poorly understood. In this study, we investigate controls on organismal size using a newly compiled database nearly 25,000 foraminiferan species and subspecies spanning past 400 million years. We find transition in pattern from correlation with atmospheric pO2 during Paleozoic (400-250 years ago) to long-term stasis post-Paleozoic (250 ago present). Thus, dramatic shift evolutionary mode coincides severe biotic catastrophe Phanerozoic (543 tracking was confined Order Fusulinida, whereas lagenides, miliolids, textulariids were best described by model. Stasis continued describe miliolids time, random walk supported for other diverse orders. The dynamics thus appears have resulted primarily selective elimination fusulinids at end Permian Period. These findings illustrate potential mass extinction alter macroevolutionary hundreds millions