Abstract
We investigated the phylogenetic relationships of species and subspecies of the cosmopolitan genus Pica using 813 bp of the mitochondrial genome (including portions of 16s rDNA, tRNA-Leu, and ND1). The phylogenetic relationships within the genus Pica revealed in our molecular analyses can be summarized as follows: (1) the Korean magpie (Pica pica sericea) appears basal within the genus Pica; (2) the European magpie (Pica pica pica) shows a close relationship to the Kamchatkan magpie (Pica pica camtschatica); (3) two North American species (Pica hudsonia and Pica nuttalli) shows a sister-group relationship; (4) most importantly, the European + Kamchatkan clade appears more closely related to the North American clade than to Korean magpies. Based on these results and genetic distance data, it is possible that members of an ancestral magpie lineage in East Asia initially moved north to form Kamchatkan magpies and then crossed the Bering land bridge to found North American taxa. At a later date, a group might have split off from Kamchatkan magpies and migrated west to form the Eurasian subspecies. The divergence between the two North American taxa appears to have happened no later than the divergence of Eurasian subspecies and both processes appear to have been relatively rapid. Rather than the formation of P. hudsonia by re-colonization from an Asian magpie ancestor, as suggested by Voous (1960), our data suggest a shared ancestry between P. hudsonia and P. nuttalli. Based on the above findings, including phylogenetic placement of P. hudsonia and P. nuttalli as nested within the larger Pica pica clade, and the lack of evidence suggesting reproductive isolation within the genus Pica, we believe that the current classification may be inaccurate. A more conservative classification would recognize one monophyletic species (i.e., P. pica) and treat P. nuttalli and P. hudsonia as subspecies (i.e., P. p. nuttalli and P. p. hudsonia). More extensive studies on the population genetics and biogeography of magpies should be conducted to better inform any taxonomic decisions.
| Original language | English |
|---|---|
| Pages (from-to) | 250-257 |
| Number of pages | 8 |
| Journal | Molecular Phylogenetics and Evolution |
| Volume | 29 |
| Issue number | 2 |
| DOIs | |
| State | Published - Nov 2003 |
Bibliographical note
Funding Information:We are grateful to Drs. C. Trost, G. Bolen, W. Koenig, and T. Yuri for generously offering samples from their personal collections. We also thank the Burke Museum, the University of Michigan Museum of Zoology, and Louisiana State University Museum of Natural Science for providing samples. We thank Drs. H.-Y. Han and K. Omland who gave us valuable comments on our draft. We also wish to thank the two anonymous referees for their help with the interpretation of phylogenetic trees. This study was partly supported by a Brain Korea 21 Research Fellowship from the Ministry of Education and Human Resources Development (to Sang-im Lee and Youna Hwang), a Basic Research Grant from the Korea Science and Engineering Foundation (KOSEF No. 1999-2-201-001-5 to Jae C. Choe), a Postdoctoral Fellowship from the Korea Research Foundation (to Cynthia S. Parr), and NSF grants (DEB-9726427 and DBI-9974525 to David P. Mindell).