molecular analysis

Wednesday, August 22, 2012

Molecular Analysis Confirms Morphological Analysis

The Aug. 6 edition of the Proceedings of the National Academy of Sciences  included a large-scale analysis of bony fishes using DNA sequencing. One of the major conclusions is that tarpons, eels and their relatives (Elopomorpha) is the sister group (branched first) of all living teleosts.

Gloria Arratia, research associate in ichthyology, first published this idea in 1997 (see reference 11 in the PNAS paper). Her conclusion was based on morphology. In short, molecular analysis  confirms a careful morphological analysis conducted about 15 years ago. More interesting is the fact that Gloria’s results were not widely accepted because the dominant figures in the field had championed the idea that the Osteoglossomorpha (mooneyes and bonytongues) were below the tarpons and eels on the tree. This inhibited some other ichthyologists from accepting Gloria's findings, in spite of the fact that she had the evidence and presented it clearly.