The butterfly family Nymphalidae contains some of the most important non-drosophilid insect model systems for evolutionary and ecological studies, yet the evolutionary history of the group has remained shrouded in mystery. We have inferred a robust phylogenetic hypothesis based on sequences of 10 genes and 235 morphological characters for exemplars of 400 of the 540 valid nymphalid genera representing all major lineages of the family. By dating the branching events, we infer that Nymphalidae originated in the Cretaceous at 90 Ma, but that the ancestors of 10 -12 lineages survived the end-Cretaceous catastrophe in the Neotropical and Oriental regions. Patterns of diversification suggest extinction of lineages at the Cretaceous/Tertiary boundary (65 Ma) and subsequent elevated speciation rates in the Tertiary.

Coevolutionary interactions are thought to have spurred the evolution of key innovations and driven the diversification of much of life on Earth. However, the genetic and evolutionary basis of the innovations that facilitate such interactions remains poorly understood. We examined the coevolutionary interactions between plants (Brassicales) and butterflies (Pieridae), and uncovered evidence for an escalating evolutionary arms-race. Although gradual changes in trait complexity appear to have been facilitated by allelic turnover, key innovations are associated with gene and genome duplications. Furthermore, we show that the origins of both chemical defenses and of molecular counter adaptations were associated with shifts in diversification rates during the arms-race. These findings provide an important connection between the origins of biodiversity, coevolution, and the role of gene and genome duplications as a substrate for novel traits.ver half a century ago, Ehrlich and Raven (1) coined the term 'coevolution' and proposed that coevolutionary interactions between species with close ecological relationships generated much of the eukaryotic biodiversity on Earth. One of their primary examples of coevolution was the chemically mediated interactions between butterflies of the subfamily Pierinae (Pieridae, Lepidoptera) and their angiosperm host-plants in the order Brassicales. Members of the plant order Brassicales are united by their production of secondary metabolites called glucosinolates (i.e., mustard oils). Upon tissue damage, glucosinolates are modified into toxins long studied for their defensive properties and flavor (e.g., mustard and horseradish) (2). In the Arabidopsis thaliana (thale cress) genome, at least 52 genes are involved in glucosinolate biosynthesis (3, 4) and some exhibit strong evidence of adaptive evolution that is attributed to herbivore mediated selection (5, 6). Pierinae caterpillars detoxify the glucosinolates of their Brassicales host-plants by redirecting these otherwise toxic breakdown products to inert metabolites using a gene that encodes a nitrile-specifier protein (7). The key innovation of the Brassicales, defensive glucosinolates, evolved roughly 90 million years ago (Ma); within 10 million years, Pierinae responded with their own key innovation, the nitrilespecifier protein, and colonized the Brassicales. Subsequently, Pierinae net diversification rates increased compared with that of their sister clade Coliadinae, whose members did not colonize Brassicales (8).Although these studies provide "perhaps the most convincing example" that the evolution of a key innovation resulted in an increased net diversification rate (9), much remains unknown about the origins and subsequent evolutionary dynamics of the key innovations that have had macroevolutionary consequences. To address this gap in the literature, here we further investigate these key innovations in the aforementioned plant and butterfly lineages by (i) assessing if these innovations increased in complexity over time and are...

Lepidoptera (butterflies and moths) represent one of the most diverse animals groups. Yet, the phylogeny of advanced ditrysian Lepidoptera, accounting for about 99 per cent of lepidopteran species, has remained largely unresolved. We report a rigorous and comprehensive analysis of lepidopteran affinities. We performed phylogenetic analyses of 350 taxa representing nearly 90 per cent of lepidopteran families. We found Ditrysia to be a monophyletic taxon with the clade Tischerioidea þ Palaephatoidea being the sister group of it. No support for the monophyly of the proposed major internested ditrysian clades, Apoditrysia, Obtectomera and Macrolepidoptera, was found as currently defined, but each of these is supported with some modification. The monophyly or near-monophyly of most previously identified lepidopteran superfamilies is reinforced, but several species-rich superfamilies were found to be para-or polyphyletic. Butterflies were found to be more closely related to 'microlepidopteran' groups of moths rather than the clade Macrolepidoptera, where they have traditionally been placed. There is support for the monophyly of Macrolepidoptera when butterflies and Calliduloidea are excluded. The data suggest that the generally short diverging nodes between major groupings in basal non-tineoid Ditrysia are owing to their rapid radiation, presumably in correlation with the radiation of flowering plants.

The geographic and temporal origins of the domestic dog remain controversial, as genetic data suggest a domestication process in East Asia beginning 15,000 years ago, whereas the oldest doglike fossils are found in Europe and Siberia and date to >30,000 years ago. We analyzed the mitochondrial genomes of 18 prehistoric canids from Eurasia and the New World, along with a comprehensive panel of modern dogs and wolves. The mitochondrial genomes of all modern dogs are phylogenetically most closely related to either ancient or modern canids of Europe. Molecular dating suggests an onset of domestication there 18,800 to 32,100 years ago. These findings imply that domestic dogs are the culmination of a process that initiated with European hunter-gatherers and the canids with whom they interacted.