Phylogeny and Historical Biogeography of Asian Pterourus Butterflies (Lepidoptera: Papilionidae): A Case of Intercontinental Dispersal from North America to East Asia.
The phylogenetic status of the well-known Asian butterflies often known as Agehana (a species group, often treated as a genus or a subgenus, within Papilio sensu lato) has long remained unresolved. Only two species are included, and one of them especially, Papilio maraho, is not only rare but near-threatened, being monophagous on its vulnerable hostplant, Sassafras randaiense (Lauraceae). Although the natural history and population conservation of "Agehana" has received much attention, the biogeographic origin of this group still remains enigmatic. To clarify these two questions, a total of 86 species representatives within Papilionidae were sampled, and four genes (concatenated length 3842 bp) were used to reconstruct their phylogenetic relationships and historical scenarios. Surprisingly, "Agehana" fell within the American Papilio subgenus Pterourus and not as previously suggested, phylogenetically close to the Asian Papilio subgenus Chilasa. We therefore formally synonymize Agehana with Pterourus. Dating and biogeographic analysis allow us to infer an intercontinental dispersal of an American ancestor of Asian Pterourus in the early Miocene, which was coincident with historical paleo-land bridge connections, resulting in the present "East Asia-America" disjunction distribution. We emphasize that species exchange between East Asia and America seems to be a quite frequent occurrence in butterflies during the Oligocene to Miocene climatic optima.
The Experimental Forest, College of Bio-Resources and Agriculture, National Taiwan University, Nantou, Taiwan.
Li-Wei
LW
Wu
Department of Biological Sciences, National Sun Yat-Sen University, Kaohsiung, Taiwan.
Shen-Horn
SH
Yen
Department of Zoology, University of Cambridge, Cambridge, United Kingdom.
David C
DC
Lees
Department of Life Science, National Taiwan Normal University, Taipei, Taiwan.
Chih-Chien
CC
Lu
Department and Graduate Institute of Entomology, National Taiwan University, Taipei, Taiwan.
Ping-Shih
PS
Yang
Department of Life Science, National Taiwan Normal University, Taipei, Taiwan.
Yu-Feng
YF
Hsu
D063147:Animal Distribution; D000818:Animals; D005075:Biological Evolution; D002080:Butterflies / Q000235:genetics*; D005202:Asia, Eastern; D008957:Models, Genetic; D009656:North America; D010802:Phylogeny