Penguin evolution: Protein comparisons demonstrate phylogenetic relationship to flying aquatic birds

Abstract

Quantitative immunological comparisons of three avian proteins, transferrin, ovalbumin, and penalbumin, indicate that penguins are phylogenetically most closely related to loons, albatrosses, herons, and grebes. These data support the theory that the ancestors of penguins were flying oceanic birds and that flightlessness in penguins has evolved independently from flightlessness in ratites.

Basal Divergences in Birds and the Phylogenetic Utility of the Nuclear RAG-1 Gene

“…These results corroborate immunological distance results (Ho et al, 1976;Prager and Wilson, 1980) for a basal position of paleognaths (using crocodylian outgroups) in avian phylogeny, with monophyly of both a chicken-duck clade and another clade for all other birds. The DNA-DNA hybridization results of Sibley and Ahlquist (1990) also supported three major clades in birds, but their study did not root the avian tree with an outgroup.…”

“…According to the RAG-1 data, paleognathous birds are the sister group of other extant birds, and neognaths are deeply divided into two clades. The paleognath-neognath division has long been recognized on morphological grounds (e.g., Pycraft, 1900) as the primary division in extant birds, and support for a galliform-anseriform clade has been growing (e.g., Ho et al, 1976;Cracraft, 1981;Sibley et al, 1988;Caspers et al, 1997;Livezey, 1997;however, see Ericson [1996] for an alternative view). Thus, our results are not startling (e.g., Sheldon and Bledsoe, 1993), but are the first with robust indicators of nodal support.…”

The Complete Mitochondrial Genome of Rhea americana and Early Avian Divergences

“…Other studies of avian ordinal relationships supporting the Palaeognathae/ Neognathae split include amino acid sequences of ␣-crystallin A and ␣-crystallin B genes (Stapel et al 1984;Caspers et al 1997), immunological distance data (Ho et al 1976;Prager and Wilson 1980), and combined mitochondrial and nuclear data sets (Cooper and Penny 1997;Hedges et al 1995). In contrast, studies of nuclear encoded cytochrome c gene (Howard et al 1974) and compositional patterns of genomes (Kadi et al 1993) did not support a particular distinction between Palaeognathae and Neognathae.…”

Tissue specific isozyme expression in three species of icterinae (Aves: Emberizidae)

“…These include members of the subfamily Icterinae (Hobart et aL, 1982), and several others from a wide selection of families (Shields, 1982;Belterman & De Boer, 1984). Additionally, micro-complement fixation studies (Prager et al, 1974;Ho et al, 1976) and sequential mitochondrial DNA comparisons among several avian and non-avian genera (Kessler & Avise, 1985) appear to corroborate the notion of conservative avian molecular evolution.…”