Sanderson Michael J
Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ 85721, USA.
Science. 2008 Jul 4;321(5885):121-3. doi: 10.1126/science.1154449.
Molecular sequence data have been sampled from 10% of all species known to science. Although it is not yet feasible to assemble these data into a single phylogenetic tree of life, it is possible to quantify how much phylogenetic signal is present. Analysis of 14,289 phylogenies built from 2.6 million sequences in GenBank suggests that signal is strong in vertebrates and specific groups of nonvertebrate model organisms. Across eukaryotes, however, although phylogenetic evidence is very broadly distributed, for the average species in the database it is equivalent to less than one well-supported gene tree. This analysis shows that a stronger sampling effort aimed at genomic depth, in addition to taxonomic breadth, will be required to build high-resolution phylogenetic trees at this scale.
分子序列数据已从科学界已知的所有物种的10%中采样。虽然将这些数据组装成一个单一的生命系统发育树目前还不可行，但有可能量化存在多少系统发育信号。对从GenBank中的260万个序列构建的14289个系统发育树的分析表明，信号在脊椎动物和特定的非脊椎动物模式生物群体中很强。然而，在整个真核生物中，尽管系统发育证据分布非常广泛，但对于数据库中的平均物种来说，它相当于不到一个得到充分支持的基因树。该分析表明，除了分类学广度外，还需要更强的采样力度以实现基因组深度，才能构建这种规模的高分辨率系统发育树。
