Evidence of constant diversification punctuated by a mass extinction in the African cycads

Ecology and Evolution

Kowiyou Yessoufou¹  Samuel O. Bamigboye¹  Barnabas H. Daru¹ 

[1] African Centre for DNA Barcoding, Department of Botany and Plant Biotechnology, University of Johannesburg, Johannesburg, South Africa

关键词: Climate change;    Encephalartos;    extinction;    gymnosperms;    adaptive radiation;    subtropical Africa.;   

DOI  :  10.1002/ece3.880

来源: Wiley

【 摘 要 】

Abstract

The recent evidence that extant cycads are not living fossils triggered a renewed search for a better understanding of their evolutionary history. In this study, we investigated the evolutionary diversification history of the genus Encephalartos, a monophyletic cycad endemic to Africa. We found an antisigmoidal pattern with a plateau and punctual explosive radiation. This pattern is typical of a constant radiation with mass extinction. The rate shift that we found may therefore be a result of a rapid recolonization of niches that have been emptied owing to mass extinction. Because the explosive radiation occurred during the transition Pliocene–Pleistocene, we argued that the processes might have been climatically mediated.

【 授权许可】

CC BY   
© 2013 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.

Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.