DNA sequence support for a close phylogenetic relationship between some storks and New World vultures.
Nucleotide sequences from the mitochondrial cytochrome b gene were used to address a controversial suggestion that New World vultures are related more closely to storks than to Old World vultures. Phylogenetic analyses of 1-kb sequences from 18 relevant avian species indicate that the similarities in morphology and behavior between New World and Old World vultures probably manifest convergent adaptations associated with carrion-feeding, rather than propinquity of descent. Direct sequence evidence for a close phylogenetic alliance between at least some New World vultures and storks lends support to conclusions reached previously from DNA.DNA hybridization methods and detailed morphology-based appraisals, and it illustrates how mistaken assumptions of homology for organismal adaptations can compromise biological classifications. However, there was a lack of significant resolution for most other branches in the cytochrome b phylogenetic reconstructions. This irresolution is most likely attributable to a close temporal clustering of nodes, rather than to ceiling effects (mutational saturation) producing an inappropriate window of resolution for the cytochrome b sequences.
Avise
J C
JC
Department of Genetics, University of Georgia, Athens 30602.
Nelson
W S
WS
Sibley
C G
CG
D000818:Animals; D001483:Base Sequence; D001717:Birds / Q000145:classification* / Q000235:genetics; D003573:Cytochrome b Group / Q000235:genetics; D017931:DNA Primers; D014644:Genetic Variation; D008969:Molecular Sequence Data; D010802:Phylogeny; D013045:Species Specificity
D003573:Cytochrome b Group; D017931:DNA Primers