四名古生物学家根据曾遍布全球的巨型蚂蚁的化石，发现了全球变暖如何影响5000万年前生命的分布。该论文发表在英国《皇家学会学报B》上。
加拿大西蒙弗雷泽大学的布鲁斯和罗尔夫、加拿大布赖顿大学的大卫·格林伍德以及美国丹佛自然科学博物馆柯克·约翰逊描述了一种新的巨型蚂蚁化石物种。这种有翼蚁后生活在5000万年前的始新世时代，其体长超过5厘米，与蜂鸟大小相近。
研究发现，巨型蚂蚁化石大多在过去曾经是热带气候的地区发现，如现今的美国怀俄明州、北美和欧洲，而现代巨型蚂蚁则分布在热带非洲地区，说明巨型蚂蚁需要生活在高温下。
在始新世时代，许多动植物物种通过当时连接着北美和欧洲两大洲的北极进行迁移。然而这些古代巨型蚂蚁如何通过温度过低的北极，非常令人困惑。研究人员猜测，始新世时代的全球变暖可能使北极出现了周期性的高温机会，让适应热带生活的生命穿越了北极。
研究人员指出，这一发现有助于科学家更好地把握全球变暖对生命的影响。理解生命形式在过去如何适应全球变暖，对人类应对未来的全球变暖十分重要。（生物谷Bioon.com）
生物谷推荐原文出处：
Proceedings of the Royal Society B: Biological Sciences DOI： 10.1098/rspb.2011.0729
Intercontinental dispersal of giant thermophilic ants across the Arctic during early Eocene hyperthermals
Archibald, S. Bruce; Johnson, Kirk R.; Mathewes, Rolf W.; Greenwood, David R.
Early Eocene land bridges allowed numerous plant and animal species to cross between Europe and North America via the Arctic.While many species suited to prevailing cool Arctic climates would have been able to cross throughout much of this period,others would have found dispersal opportunities only during limited intervals when their requirements for higher temperatureswere met. Here, we present Titanomyrma lubei gen. et sp. nov. from Wyoming, USA, a new giant (greater than 5 cm long) formiciine ant from the early Eocene (approx. 49.5Ma) Green River Formation. We show that the extinct ant subfamily Formiciinae is only known from localities with an estimatedmean annual temperature of about 20°C or greater, consistent with the tropical ranges of almost all of the largest livingant species. This is, to our knowledge, the first known formiciine of gigantic size in the Western Hemisphere and the firstreported cross-Arctic dispersal by a thermophilic insect group. This implies intercontinental migration during one or morebrief high-temperature episodes (hyperthermals) sometime between the latest Palaeocene establishment of intercontinental landconnections and the presence of giant formiciines in Europe and North America by the early middle Eocene.
