Limits of Adaptation and Microbial Extinction in the Antarctic Desert

隐石内微生物在上面几毫米处定居 南极沙漠的石灰岩 这些微生物生活在 在一个极端的环境中， 他们的生理潜能。 来自融雪和光照的水 穿透岩石，但生长似乎受到极端的限制， 低环境温度。 气候梯度已经被观察到 横跨位于麦克默多干谷的一系列地点。 这项研究将量化环境条件。 自动 数据记录器将监测岩石内部的微尺度气候， 基于这些测量的计算机模型将有助于 确定生命与环境之间的确切阈值 灭绝 透射电子显微镜将用于 记录死亡社区的退化和 遗迹化石 这里所研究的群落 作为早期火星生命最后阶段的地球模型。 这些研究的结果将有助于重建 在火星上的灭绝过程，并建议其目前的形式- 日间的痕迹。 该项目由以下机构共同支持： 国家科学基金会和国家航空航天局， 太空管理局。

Cryptoendolithic microorganisms colonize the upper few millimeters of limestone rocks of the Antarctic desert. These microbes live in a critically extreme environment, near the absolute limit of their physiological potential. Water from snowmelt and light penetrate the rocks but growth appears to be limited by the extreme low ambient temperatures. A climatic gradient has been observed to span a range of sites located in the McMurdo Dry Valleys. This study will quantify environmental conditions. Automatic data loggers will monitor the microscale climate inside rocks, and computer models based on these measurements will help identify the exact environmental threshold between life and extinction. Transmission electron microscopy will be used to document the degradation of dead communities and the formation of trace fossils. The communities studied here have been proposed as a terrestrial model for the last stages of life on early Mars. The results of these studies will serve to reconstruct the process of extinction on Mars and suggest the form its present- day traces might take. This project is jointly supported by the National Science Foundation and the National Aeronautics and Space Administration.