Klass Klaus-Dieter, Nalepa Christine, Lo Nathan
State Natural History Collections Dresden, Museum of Zoology, Königsbrücker Landstrasse 159, D-01109 Dresden, Germany.
Mol Phylogenet Evol. 2008 Mar;46(3):809-17. doi: 10.1016/j.ympev.2007.11.028. Epub 2007 Dec 7.
Isoptera are highly specialized cockroaches and are one of the few eusocial insect lineages. Cryptocercus cockroaches have appeared to many as ideal models for inference on the early evolution of termites, due to their possible phylogenetic relationship and several shared key attributes in life history. Recently, Pellens, Grandcolas, and colleagues have proposed the blaberid cockroach Parasphaeria boleiriana to be an alternative model for the early evolution in termites. We compare the usefulness of Cryptocercus and P. boleiriana as models for termite evolution. Cryptocercus and lower Isoptera (1) can both feed on comparatively recalcitrant wood, (2) have an obligate, rich and unique hypermastigid and oxymonadid fauna in the hindgut, (3) transfer these flagellates to the next generation by anal trophallaxis, (4) have social systems that involve long-lasting biparental care, and, finally, (5) are strongly suggested to be sister groups, so that the key attributes (1)-(4) appear to be homologous between the two taxa. On the other hand, P. boleiriana (1) feeds on soft, ephemeral wood sources, (2) shows no trace of the oxymonadid and hypermastigid hindgut fauna unique to Cryptocercus and lower Isoptera, nor does it have any other demonstrated obligate relationship with hindgut flagellates, (3) is likely to lack anal trophallaxis, (4) has only a short period of uniparental brood care, and (5) is phylogenetically remote from the Cryptocercus+Isoptera clade. These facts would argue against any reasonable usage of P. boleiriana as a model for the early evolution of Isoptera or even of the clade Cryptocercus+Isoptera. Cryptocercus thus remains an appropriate model-taxon-by-homology for early termite evolution. As compared to P. boleiriana, some other Blaberidae (such as the Panesthiinae Salganea) appear more useful as model-taxa-by-homoplasy for the early evolution of the Cryptocercus+Isoptera clade, as their brooding behavior is more elaborate than in P. boleiriana.
等翅目昆虫是高度特化的蟑螂，是少数几个具有真社会性的昆虫谱系之一。由于隐尾蠊可能的系统发育关系以及在生活史中几个共同的关键特征，在许多人看来，隐尾蠊是推断白蚁早期进化的理想模型。最近，佩伦斯、格兰德科拉斯及其同事提出，蜚蠊科蟑螂博氏副球蠊是白蚁早期进化的另一种模型。我们比较了隐尾蠊和博氏副球蠊作为白蚁进化模型的实用性。隐尾蠊和低等等翅目昆虫（1）都能以相对难消化的木材为食，（2）后肠中有专性的、丰富且独特的超鞭毛虫和微单鞭毛虫动物群，（3）通过肛门交哺将这些鞭毛虫传递给下一代，（4）具有涉及长期双亲照料的社会系统，最后，（5）强烈推测它们是姐妹群，因此两个类群之间的关键特征（1）-（4）似乎是同源的。另一方面，博氏副球蠊（1）以柔软、短暂的木材来源为食，（2）没有隐尾蠊和低等等翅目昆虫特有的微单鞭毛虫和超鞭毛虫后肠动物群的踪迹，也没有与后肠鞭毛虫的任何其他已证实的专性关系，（3）可能缺乏肛门交哺，（4）只有短时间的单亲育雏照料，并（5）在系统发育上与隐尾蠊+等翅目类群相距甚远。这些事实表明，博氏副球蠊不能合理地用作等翅目甚至隐尾蠊+等翅目类群早期进化的模型。因此，隐尾蠊仍然是早期白蚁进化的一个合适的同源模型类群。与博氏副球蠊相比，一些其他蜚蠊科昆虫（如拟甲蠊属的萨尔加蠊）作为隐尾蠊+等翅目类群早期进化的同功模型类群似乎更有用，因为它们的育雏行为比博氏副球蠊更复杂。
