美国生物学家最近在巴西境内的亚马逊雨林发现了一种新蚂蚁，初步认定这可能是最古老蚂蚁的后代。由于这种蚂蚁有许多前所未见的特征，生物学家称之为“火星来的蚂蚁”。
来自得克萨斯大学的克里斯蒂安·拉伯尔等人在新一期美国《国家科学院院刊》（PNAS）上介绍说，这种蚂蚁通体呈金黄色，在土壤中生存，体长2到3毫米，没有眼睛，但有很大的大颚。由于它是肉食性蚂蚁，拉伯尔等人猜测它的大颚是捕食的利器。
经过形态学和基因分析，拉伯尔等人将这种蚂蚁归入单独一个亚科。这是自1923年以来，科学家第一次发现隶属于新亚科的活蚂蚁，其他的新亚科蚂蚁都是以化石形式被发现的。目前已知的蚂蚁亚科共有21个。
对这种蚂蚁腿部的DNA（脱氧核糖核酸）分析结果显示，这种蚂蚁很可能是最古老蚂蚁家族的后裔，处于蚂蚁进化树的最初始阶段。
蚂蚁和黄蜂有着共同的祖先，大约在距今1.2亿年前，在进化道路上“分家”。蚂蚁的种类相当丰富，具有重要的生态学研究价值。拉伯尔说，这一新发现将有助于生物学家更好地理解蚂蚁的生物多样性和进化历程，“这种新蚂蚁的发现说明，可能还有很多新的蚂蚁种类，甚至是巨大的进化线索埋藏在热带雨林的土壤中”。（生物谷Bioon.com）
生物谷推荐原始出处：
PNAS，doi: 10.1073/pnas.0806187105，Christian Rabeling，Manfred Verhaagh
Newly discovered sister lineage sheds light on early ant evolution
Christian Rabeling, Jeremy M. Brown, and Manfred Verhaagh
Ants are the world's most conspicuous and important eusocial insects and their diversity, abundance, and extreme behavioral specializations make them a model system for several disciplines within the biological sciences. Here, we report the discovery of a new ant that appears to represent the sister lineage to all extant ants (Hymenoptera: Formicidae). The phylogenetic position of this cryptic predator from the soils of the Amazon rainforest was inferred from several nuclear genes, sequenced from a single leg. Martialis heureka (gen. et sp. nov.) also constitutes the sole representative of a new, morphologically distinct subfamily of ants, the Martialinae (subfam. nov.). Our analyses have reduced the likelihood of long-branch attraction artifacts that have troubled previous phylogenetic studies of early-diverging ants and therefore solidify the emerging view that the most basal extant ant lineages are cryptic, hypogaeic foragers. On the basis of morphological and phylogenetic evidence we suggest that these specialized subterranean predators are the sole surviving representatives of a highly divergent lineage that arose near the dawn of ant diversification and have persisted in ecologically stable environments like tropical soils over great spans of time.
