Chuanlun L. Zhang,^1* Ann Pearson,² Yi-Liang Li,^1† Gary Mills,¹ and Juergen Wiegel³

Savannah River Ecology Laboratory, University of Georgia, Aiken, South Carolina 29802¹
Department of Earth and Planetary Sciences, Harvard University, Cambridge, Massachusetts 02138²
Department of Microbiology, University of Georgia, Athens, Georgia 30605³

Abstract
The isoprenoid lipid crenarchaeol is widespread in hot springs of California and Nevada. Terrestrial and marine data together suggest a maximum relative abundance of crenarchaeol at 40°C. This warm temperature optimum may have facilitated colonization of the ocean by (hyper)thermophilic Archaea and the major marine radiation of Crenarchaeota.

Keywords: Ambystoma opacum, catastrophic reproductive failure, extinction, larval density dependence, pond-breeding salamander, population model, storage effects, terrestrial survival

* Corresponding author. Mailing address: Savannah River Ecology Laboratory, University of Georgia, Aiken, SC 29802. Phone: (803) 725-5299. Fax: (803) 725-3309. E-mail: zhang@srel.edu

†Present address: Center for Biomarker Analysis, University of Tennessee, Knoxville, TN 37932-2575.