查尔斯·达尔文在他访问加拉帕戈斯群岛的时候忽略的一种粉色陆地鬣蜥物种可能提供了这种古老动物在这个群岛上的分化提供了证据。达尔文在1835年访问加拉帕戈斯群岛的时候没能探索伊莎贝尔岛上的Volcan Wolf火山，那是新发现的Conolophus属陆地鬣蜥——“rosada” 鬣蜥的唯一家园。
Gabriele Gentile及其同事对rosada鬣蜥和其他陆地鬣蜥进行的遗传分析表明rosada鬣蜥起源自超过500万年前的加拉帕戈斯，而且在这个群岛仍然在形成的过程中与岛上的其它鬣蜥种群分开了。Rosada鬣蜥和其他陆地鬣蜥的古老分化——早在Volcan Wolf火山形成之前——为加拉帕戈斯群岛记录的最古老的分化事件之一提供了证据。这组作者警告说，这种最近才被承认的鬣蜥物种可能已经濒危，而且可能会灭绝。（生物谷Bioon.com）
生物谷推荐原始出处：
PNAS January 5, 2009, doi: 10.1073/pnas.0806339106
An overlooked pink species of land iguana in the Galápagos
Gabriele Gentilea,1, Anna Fabiania, Cruz Marquezb, Howard L. Snellc, Heidi M. Snellc, Washington Tapiad, and Valerio Sbordonia
aDipartimento di Biologia, Università Tor Vergata, 00133 Rome, Italy
bCharles Darwin Foundation, Puerto Ayora, Galápagos Islands, Ecuador
cDepartment of Biology and Museum of Southwestern Biology, University of New Mexico, Albuquerque, NM 87131; and
dGalápagos National Park Service, Puerto Ayora, Galápagos Islands, Ecuador
Despite the attention given to them, the Galápagos have not yet finished offering evolutionary novelties. When Darwin visited the Galápagos, he observed both marine (Amblyrhynchus) and land (Conolophus) iguanas but did not encounter a rare pink black-striped land iguana (herein referred to as “rosada,” meaning “pink” in Spanish), which, surprisingly, remained unseen until 1986. Here, we show that substantial genetic isolation exists between the rosada and syntopic yellow forms and that the rosada is basal to extant taxonomically recognized Galápagos land iguanas. The rosada, whose present distribution is a conundrum, is a relict lineage whose origin dates back to a period when at least some of the present-day islands had not yet formed. So far, this species is the only evidence of ancient diversification along the Galápagos land iguana lineage and documents one of the oldest events of divergence ever recorded in the Galápagos. Conservation efforts are needed to prevent this form, identified by us as a good species, from extinction.
