RESUMO
Temperature is thought to be a key factor influencing global species richness patterns. We investigate the link between temperature and diversification in the butterfly family Pieridae by combining next generation DNA sequences and published molecular data with fine-grained distribution data. We sampled nearly 600 pierid butterfly species to infer the most comprehensive molecular phylogeny of the family and curated a distribution dataset of more than 800,000 occurrences. We found strong evidence that species in environments with more stable daily temperatures or cooler maximum temperatures in the warm seasons have higher speciation rates. Furthermore, speciation and extinction rates decreased in tandem with global temperatures through geological time, resulting in a constant net diversification.
RESUMO
The world's largest butterfly genus Delias, commonly known as Jezebels, comprises ca. 251 species found throughout Asia, Australia, and Melanesia. Most species are endemic to islands in the Indo-Australian Archipelago or to New Guinea and nearby islands in Melanesia, and many species are restricted to montane habitats over 1200 m. We inferred an extensively sampled and well-supported molecular phylogeny of the group to better understand the spatial and temporal dimensions of its diversification. The remarkable diversity of Delias evolved in just ca. 15-16 Myr (crown age). The most recent common ancestor of a clade with most of the species dispersed out of New Guinea ca. 14 Mya, but at least six subsequently diverging lineages dispersed back to the island. Diversification was associated with frequent dispersal of lineages among the islands of the Indo-Australian Archipelago, and the divergence of sister taxa on a single landmass was rare and occurred only on the largest islands, most notably on New Guinea. We conclude that frequent inter-island dispersal during the Neogene-likely facilitated by frequent sea level change-sparked much diversification during that period. Many extant New Guinea lineages started diversifying 5 Mya, suggesting that orogeny facilitated their diversification. Our results largely agree with the most recently proposed species group classification system, and we use our large taxon sample to extend this system to all described species. Finally, we summarize recent insights to speculate how wing pattern evolution, mimicry, and sexual selection might also contribute to these butterflies' rapid speciation and diversification.
Assuntos
Borboletas , Animais , Filogenia , Borboletas/genética , Nova Guiné , Austrália , EcossistemaRESUMO
The eichhorni group lies within the genus Delias (Lepidoptera: Pieridae) which has markedly diversified aposematic wing markings. The phylogenetic relationships among all species of the eichhorni group, representatives of each of the other 21 species groups of Delias butterflies, and some related genera were analyzed based on nucleotide sequences of the mitochondrial NADH dehydrogenase subunit 5 gene. A supplemental study using the nuclear elongation factor-1alpha (EF-1alpha) gene was also carried out. The results are compared with those of morphological studies. Our results confirm the monophyly of the eichhorni group and suggest the monophyly of the genus Delias. They also indicate phylogenetic intragroup relationships, particularly the division of the eichhorni complex into groups I and II. Moreover, they also indicate that the initial diversification of the eichhorni group involved separation of the D. catisa + D. toxopei clade, followed by the divergence of other species including the eichhorni complex. Based on these findings, it is supposed that this group first appeared close to or within the western mountain range of New Guinea Island (135 degrees 30(')-140 degrees E) where D. catisa, D. toxopei, and representatives of other species cohabit.
