Phylogenetic analysis of the 24 named albatross taxa based on full mitochondrial cytochrome b DNA sequences | Notornis and Birds New Zealand

摘要

A stable evidence-based taxonomy is a critical requirement for the effective future conservation of the albatrosses. Recently published partial molecular phylogenies are in broad agreement with respect to the structure of the evolutionary tree for most named taxa, but the analytical methods used to create them have been seriously criticised and they must be considered provisional at best. A further problem is that their authors reach startlingly different conclusions regarding the numbers of taxa which should be recognised as species; 13 vs. 24. Here, we attempt to resolve this situation by supplying full length mitochondrial cytochrome b data presently missing for 2 taxa, carrying out thorough phylogenetic analyses meeting the requirements of published prescriptions and taking into full account other sources of new molecular data and contemporary opinions on albatross nomenclature and the status of taxa. We provide general support for the published trees and critically evaluate claims regarding how many taxa represent full species. Some genetic distances between pairs of taxa are so small that considerable weight of alternative evidence is required to support any decision leading to a recommendation to split them. We note that the empirical boundary between consensus and controversy falls at or around 1% DNA sequence divergence and further that few, if any, commentators recognise taxa that are separated by less than 0.1% as being valid species.