沙丘中的南非剑羚，纳米比亚 Gemsbok (Oryx gazella) in sand dunes, Namibia (© Sergey Gorshkov/Alamy)

沙丘中的南非剑羚，纳米比亚 Gemsbok (Oryx gazella) in sand dunes, Namibia (© Sergey Gorshkov/Alamy)

被沙海包围 Surrounded by a sea of sand

纳米比亚沙丘上的南非剑羚

“生命总会找到出路。”虽然《侏罗纪公园》中的马尔科姆博士是在谈论恐龙繁殖，但这句话也适用于生命如何在地球上最恶劣的环境中存活。极端生物是一种可以生活在极端环境下的生物，包括高温、低温或其他超出生命所能适应的条件。例如，在寒冷的北极地区，企鹅和北极熊可以生存；在炎热的沙漠中，骆驼可以不喝一滴水存活几个月；在高酸高温高压的海洋环境中，海洋微生物依然可以茁壮成长。

Gemsbok in Namibian sand dunes

To quote Jurassic Park's Dr. Malcolm: 'Life, uh, finds a way.' Animals and plants are found in some of Earth's most inhospitable places, from penguins and polar bears in the freezing Arctic to camels in scalding deserts. This lonely gemsbok, seen here in sand dunes in Namibia, is used to living in an inhospitable environment. Also known as the oryx, it is native to the arid regions of Southern Africa, especially around the Namib and Kalahari deserts. The gemsbok does not need to drink much water, instead finding hydration in the vegetation it grazes upon—including wild tsamma melons and cucumbers. When vegetation is sparse, they can dig deep to find roots and tubers to supplement their diet.