Gerardo Lamas

Butterfly genome reveals promiscuous exchange of mimicry adaptations among species

The evolutionary importance of hybridization and introgression has long been debated. Hybrids are usually rare and unfit, but even infrequent hybridization can aid adaptation by transferring beneficial traits between species. Here we use genomic tools to investigate introgression in Heliconius, a rapidly radiating genus of neotropical butterflies widely used in studies of ecology, behaviour, mimicry and speciation. We sequenced the genome of Heliconius melpomene and compared it with other taxa to investigate chromosomal evolution in Lepidoptera and gene flow among multiple Heliconius species and races. Among 12,669 predicted genes, biologically important expansions of families of chemosensory and Hox genes are particularly noteworthy. Chromosomal organization has remained broadly conserved since the Cretaceous period, when butterflies split from the Bombyx (silkmoth) lineage. Using genomic resequencing, we show hybrid exchange of genes between three co-mimics, Heliconius melpomene, Heliconius timareta and Heliconius elevatus, especially at two genomic regions that control mimicry pattern. We infer that closely related Heliconius species exchange protective colour-pattern genes promiscuously, implying that hybridization has an important role in adaptive radiation.

Indigenous people incorporated? Culture as politics, culture as property in pharmaceutical bioprospecting. Commentaries. Author's reply

The ongoing debate over indigenous claims to intellectual and cultural property reveals a series of indigenous strategies of mobilization that both appropriate from and work against the logic of the market. Of particular significance in this regard are the various indigenous strategies used in contemporary pharmaceutical bioprospecting activities to address claims to traditional medical knowledge as cultural property. This article presents field data on a controversial ethnopharmaceutical project among the Aguaruna of Perus high forest and offers a comparative analysis of the outcomes with attention to several other cases in and beyond South America. In particular, questions are raised about the forms of legitimating authority in the burgeoning international indigenous movement, the role of NGOs, researchers, bureaucracies, and corporations in this process, and the dilemmas that emerge from the politicization and privatization of indigenous culture and identity.The ongoing debate over indigenous claims to intellectual and cultural property reveals a series of indigenous strategies of mobilization that both appropriate from and work against the logic of the market. Of particular significance in this regard are the various indigenous strategies used in contemporary pharmaceutical bioprospecting activities to address claims to traditional medical knowledge as cultural property. This article presents field data on a controversial ethnopharmaceutical project among the Aguaruna of Perus high forest and offers a comparative analysis of the outcomes with attention to several other cases in and beyond South America. In particular, questions are raised about the forms of legitimating authority in the burgeoning international indigenous movement, the role of NGOs, researchers, bureaucracies, and corporations in this process, and the dilemmas that emerge from the politicization and privatization of indigenous culture and identity.

Strikingly variable divergence times inferred across an Amazonian butterfly ‘suture zone’

‘Suture zones’ are areas where hybrid and contact zones of multiple taxa are clustered. Such zones have been regarded as strong evidence for allopatric divergence by proponents of the Pleistocene forest refugia theory, a vicariance hypothesis frequently used to explain diversification in the Amazon basin. A central prediction of the refugia and other vicariance theories is that the taxa should have a common history so that divergence times should be coincident among taxa. A suture zone for Ithomiinae butterflies near Tarapoto, NE Peru, was therefore studied to examine divergence times of taxa in contact across the zone. We sequenced 1619 bp of the mitochondrial COI/COII region in 172 individuals of 31 species from across the suture zone. Inferred divergence times differed remarkably, with divergence between some pairs of widespread species (each of which may have two or more subspecies interacting in the zone, as in the genus Melinaea) being considerably less than that between hybridizing subspecies in other genera (for instance in Oleria). Our data therefore strongly refute a simple hypothesis of simultaneous vicariance and suggest that ongoing parapatric or other modes of differentiation in continuous forest may be important in driving diversification in Amazonia.

Systematics of Hypanartia (Lepidoptera: Nymphalidae: Nymphalinae), with a test for geographical speciation mechanisms in the Andes

A taxonomic review of the Neotropical nymphaline butterfly genus Hypanartia Hübner is presented, including notes on the taxonomy, biology and distribution of its component species, illustrations of all taxa and the male genitalia of all species, and the description of four new species and two new subspecies: Hypanartia celestia sp.n., H. cinderella sp.n., H. dione disjuncta ssp.n., H. fassli sp.n., H. trimaculata sp.n. and H. trimaculata autumna ssp.n. Hypanartia arcaei (Salvin) is placed as a subspecies of H. dione (Latreille) (stat.n.) and lectotypes are designated for eight nominal taxa. Fourteen species are recognized, with the centre of diversity being in high Andean cloud forest habitats. A cladistic analysis was conducted, based on fifty‐three illustrated characters of male genitalic and abdominal morphology, and external facies, to investigate phylogenetic relationships. The resulting phylogenetic hypothesis was used to test four different geographical mechanisms of speciation in the Andes: colonization from temperate latitudes, speciation across elevational gradients, radiation within the Andes and allopatric speciation between the Andes and other montane regions. There is evidence that speciation across an elevational gradient occurred twice, both times into elevations largely unoccupied by the genus, and in both cases followed by subsequent, elevationally sympatric, in situ radiation. Differentiation in allopatry between montane regions has apparently been of recent influence only, causing infraspecific variation in two species. These results parallel several recent studies of Andean bird speciation.

The anatomy of a 'suture zone' in Amazonian butterflies: a coalescent-based test for vicariant geographic divergence and speciation.

Attempts by biogeographers to understand biotic diversification in the Amazon have often employed contemporary species distribution patterns to support particular theories, such as Pleistocene rainforest refugia, rather than to test among alternative hypotheses. Suture zones, narrow regions where multiple contact zones and hybrid zones between taxa cluster, have been seen as evidence for past expansion of whole biotas that have undergone allopatric divergence in vicariant refuges. We used coalescent analysis of mutilocus sequence data to examine population split times in 22 pairs of geminate taxa in ithomiine and heliconiine butterflies. We test a hypothesis of simultaneous divergence across a suture zone in NE Peru. Our results reveal a scattered time course of diversification in this suture zone, rather than a tight cluster of split times. Additionally, we find rapid diversification within some lineages such as Melinaea contrasting with older divergence within lineages such as the Oleriina (Hyposcada and Oleria). These results strongly reject simple vicariance as a cause of the suture zone. At the same time, observed lineage effects are incompatible with a series of geographically coincident vicariant events which should affect all lineages similarly. Our results suggest that Pleistocene climatic forcing cannot readily explain this Peruvian suture zone. Lineage‐specific biological traits, such as characteristic distances of gene flow or varying rates of parapatric divergence, may be of greater importance.

A Multipronged Approach to the Study of Peruvian Ethnomedicinal Plants: A Legacy of the ICBG-Peru Project△

A multidisciplinary and international team of scientists was assembled in the early 1990s to conduct an ethnobotanical study of plants used by the Aguaruna people of the Peruvian Amazon forest. The initial ethnobotanical project, carried out under the auspices of an International Cooperative Biodiversity Grant (ICBG), led to the collection of approximately 4000 plant species. Some members of the original team of scientists have continued this collaboration by focusing on potential sources of new anticancer, anti-infective, and wound-healing agents. This effort has uncovered several secondary metabolites representing a wide variety of chemical diversity. In this short review we describe some bioactive compounds of interest as part of our continuing collaboration.

A phylogenetic reassessment of Hyalenna Forbes and Dircenna Doubleday, with a revision of Hyalenna (Lepidoptera: Nymphalidae: Ithomiinae)

Abstract.  A morphological study of adults and immature stages and a cladistic analysis were conducted to clarify the relationships amongst members of the sister nymphalid butterfly genera Dircenna Doubleday and Hyalenna Forbes. Two species formerly included in Dircenna, Ithomia paradoxa Staudinger and Dircenna hugia Schaus, clustered with Ithomia perasippa, the type species of Hyalenna. Therefore, the first two species are transferred from Dircenna to Hyalenna (comb.n.). Hyalenna and Dircenna as now conceived are both monophyletic and well supported by morphological apomorphies and branch support measures. The taxonomy and classification of Hyalenna are reviewed and seven species and twenty‐four taxa are recognized, including one new species, Hyalenna buckleyisp.n., and eleven new subspecies: Hyalenna paradoxa incachacassp.n., H. perasippa valenciassp.n., H. perasippa ortygiosassp.n., H. perasippa solitariassp.n., H. buckleyi pomacochassp.n., H. alidella exsulansssp.n., H. alidella cinereolassp.n., H. alidella vescassp.n., H. sulmona balsamicassp.n., H. sulmona hyalinassp.n. and H. sulmona tersassp.n. A key for the identification of all taxa, and illustrations of male and female genitalia for all species and adult specimens of all taxa (where known), are presented. The natural history of each species is summarized and the immature stages of H. paradoxa and H. sulmona are described for the first time.

Into the Andes: multiple independent colonizations drive montane diversity in the Neotropical clearwing butterflies Godyridina

Understanding why species richness peaks along the Andes is a fundamental question in the study of Neotropical biodiversity. Several biogeographic and diversification scenarios have been proposed in the literature, but there is confusion about the processes underlying each scenario, and assessing their relative contribution is not straightforward. Here, we propose to refine these scenarios into a framework which evaluates four evolutionary mechanisms: higher speciation rate in the Andes, lower extinction rates in the Andes, older colonization times and higher colonization rates of the Andes from adjacent areas. We apply this framework to a species‐rich subtribe of Neotropical butterflies whose diversity peaks in the Andes, the Godyridina (Nymphalidae: Ithomiini). We generated a time‐calibrated phylogeny of the Godyridina and fitted time‐dependent diversification models. Using trait‐dependent diversification models and ancestral state reconstruction methods we then compared different biogeographic scenarios. We found strong evidence that the rates of colonization into the Andes were higher than the other way round. Those colonizations and the subsequent local diversification at equal rates in the Andes and in non‐Andean regions mechanically increased the species richness of Andean regions compared to that of non‐Andean regions (‘species‐attractor’ hypothesis). We also found support for increasing speciation rates associated with Andean lineages. Our work highlights the importance of the Andean slopes in repeatedly attracting non‐Andean lineages, most likely as a result of the diversity of habitats and/or host plants. Applying this analytical framework to other clades will bring important insights into the evolutionary mechanisms underlying the most species‐rich biodiversity hotspot on the planet.

Patterns of Richness, Composition, and Distribution of Sphingid Moths Along an Elevational Gradient in the Andes-Amazon Region of Southeastern Peru

ABSTRACT The adult sphingid communities of three sites in southeastern Peru representative of the moist tropical forest of the lowland Amazon, the pluvial tropical forest of the upper Amazon and Andean foothills, and the montane cloud forest of the eastern slopes of the Andes were sampled during 2004–2006 by using mercury vapor light traps. In total, 119 species of Sphingidae were documented. Species diversity was highest in the upper Amazon and Andean foothills, with 94 species (21 genera), followed by 80 species (21 genera) in the Amazonian lowlands, and 43 species (17 genera) in the montane cloud forest. The greatest number of endemics (22) was registered at the upper AmazonAndean foothills site. The montane cloud forest site was characterized by the highest relative percentage of endemic species. The species assemblages of the lowland Amazon and the Andean foothills were more similar in composition to each other than to the montane assemblage. All three assemblages proved to be more distinctive than expected based on the proximity of the sampled sites and seemingly good flight capabilities of sphingid moths. This was reflected by the endemics accounting for nearly 40% of the total species pool. By contrast, cosmopolitans numbered only 26 species, or 22% of the total assemblage. We hypothesize that the composition and distribution of sphingid species along this elevational gradient may reflect floristic similarities and differences between the study sites and the extent to which different species are adapted to cope with certain environmental conditions, such as temperature and air humidity.

North Andean origin and diversification of the largest ithomiine butterfly genus

The Neotropics harbour the most diverse flora and fauna on Earth. The Andes are a major centre of diversification and source of diversity for adjacent areas in plants and vertebrates, but studies on insects remain scarce, even though they constitute the largest fraction of terrestrial biodiversity. Here, we combine molecular and morphological characters to generate a dated phylogeny of the butterfly genus Pteronymia (Nymphalidae: Danainae), which we use to infer spatial, elevational and temporal diversification patterns. We first propose six taxonomic changes that raise the generic species total to 53, making Pteronymia the most diverse genus of the tribe Ithomiini. Our biogeographic reconstruction shows that Pteronymia originated in the Northern Andes, where it diversified extensively. Some lineages colonized lowlands and adjacent montane areas, but diversification in those areas remained scarce. The recent colonization of lowland areas was reflected by an increase in the rate of evolution of species’ elevational ranges towards present. By contrast, speciation rate decelerated with time, with no extinction. The geological history of the Andes and adjacent regions have likely contributed to Pteronymia diversification by providing compartmentalized habitats and an array of biotic and abiotic conditions, and by limiting dispersal between some areas while promoting interchange across others.