Australia: The Land Where Time Began

A biography of the Australian continent 

Eukaryote Tree - Rooting by the Use of a Derived Gene Fusion

According to Stechmann & Cavalier-Smith single-gene trees have not been successful in locating the root of the eukaryote tree because of systematic biases in sequence evolution. They suggest more reliable insights into deep phylogenetic relationships should be yielded by structural genetic data. According to Stechmann & Cavalier-Smith they searched for the presence or absence of a gene fusion in major protist groups in an attempt to locate the root of the eukaryote tree. In this paper Stechmann & Cavalier-Smith say they have shown that all groups of eukaryotes ancestrally with 2 cilia (bikonts) are derived evolutionarily, which they say is in striking contrast to previous molecular studies. The root lies between bikonts and opisthokonts (animals, Fungi, Choanozoa). Amoebozoa either diverged even earlier or are sister groups of bikonts, or what is considered less likely, opisthokonts.

Sources & Further reading

1. Stechmann, A. and T. Cavalier-Smith (2002). "Rooting the Eukaryote Tree by Using a Derived Gene Fusion." Science 297(5578): 89-91.