Anomalous Variation in Mitochondrial Genomes of White-Crowned (Zonotrichia leucophrys) and Golden-Crowned (Z. atricapilla) Sparrows: Pseudogenes, Hybridization, or Incomplete Lineage Sorting?

Towards a phylogenetic framework for the evolution of shakes, rattles, and rolls in Myiarchus tyrant-flycatchers (Aves: Passeriformes: Tyrannidae)

“…To illustrate concordances and discordances between mtDNA and morphology, we review cases of paraphyly and their systematic implications. Also, because renewed concern has been expressed lately (e.g., Ballard et al, 2002;Weckstein et al, 2001) about making taxonomic changes based solely on mtDNA, we offer our findings as a focus for further questions that should be addressed with characters from nuclear DNA, morphology and voice.…”

“…We plan separate, more detailed discussions of intraspecific phylogeography for later publications but have already examined the phylogeography and evolution of migration in the M. swainsoni complex (Joseph et al, 2003). Renewed concern has been expressed lately (e.g., Ballard et al, 2002;Weckstein et al, 2001) about making taxonomic changes based solely on mtDNA and so we offer our findings with this in mind.…”

Early song discrimination by nestling sparrows in the wild

“…An important question is whether such mechanisms to reduce learning errors evolve as a consequence of reinforcement (Servedio et al, 2009). While there are no currently recognized hybrid zones between golden-crowned sparrows and white-crowned sparrows, patterns of mitochondrial introgression suggest that hybridization may have occurred in the recent past (Weckstein et al, 2001). The evolution of early song discrimination and subsequent bias in learning could have been a consequence of reinforcement during this period of past hybridization.…”

“…Golden-crowned sparrows and white-crowned sparrows are sister species (Carson and Spicer, 2003;Weckstein et al, 2001;Zink and Blackwell, 1996) that share sympatric breeding ranges in western North America. While there are occasional reports of hybrids (Miller, 1940), the two species are not known to maintain any hybrid zones.…”

Major analytical and conceptual shortcomings in a recent taxonomic revision of the Procellariiformes—a reply to Penhallurick and Wink (2004)

“…Yet another problem with mitochondrial genetic divergences is the potential for a brief spell of past hybridisation of contemporary unequivocal species. Weckstein et al (2001) found zero genetic divergence between two uncontested species of Zonotrichia sparrow, which belong to a family that is usually characterised by rather high divergences between sister taxa (Klicka and Zink 1997). They hypothesised that this pattern arose from past hybridisation among two species that are ecologically well segregated nowadays.…”