Limits...
North Andean origin and diversification of the largest ithomiine butterfly genus

View Article: PubMed Central - PubMed

ABSTRACT

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.

No MeSH data available.


Speciation rate through time estimated by the best fitting model of diversification (Table 4).The model was fitted on the MCC tree and on 100 trees. The dotted line corresponds to the speciation rate of the MCC tree. The plain line corresponds to the mean speciation rate from the 100 trees, and dashed lines correspond to the 95% confidence interval. The figure was generated with R (https://cran.r-project.org/).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC5384087&req=5

f5: Speciation rate through time estimated by the best fitting model of diversification (Table 4).The model was fitted on the MCC tree and on 100 trees. The dotted line corresponds to the speciation rate of the MCC tree. The plain line corresponds to the mean speciation rate from the 100 trees, and dashed lines correspond to the 95% confidence interval. The figure was generated with R (https://cran.r-project.org/).

Mentions: We first investigated heterogeneity among clades for speciation and extinction rates using MEDUSA48 on the MCC tree and on 100 trees from the posterior distribution. No significant shift of diversification rates was found on the MCC tree. Five trees of the posterior distribution (5%) had at least one significant shift of diversification rates. Each of those shifts was found in less than 5% of the trees, and therefore considered as non-significant. We then investigated whether diversification rates varied through time by fitting time-dependent models of speciation and extinction rates49. The best fitting model was an exponential time-dependent speciation rate without extinction (Table 4). According to this model speciation rate decreased from 0.646 event per lineage per million year for the MCC tree and 0.538 ± 0.024 for the 100 trees at the origin of the genus (crown) to 0.148 for the MCC tree and 0.159 ± 0.002 for the 100 trees at present (Fig. 5). All other models, including the constant speciation rate model, were rejected at the threshold of ΔAIC > 2, strengthening the support for a decreasing speciation rate through time.


North Andean origin and diversification of the largest ithomiine butterfly genus
Speciation rate through time estimated by the best fitting model of diversification (Table 4).The model was fitted on the MCC tree and on 100 trees. The dotted line corresponds to the speciation rate of the MCC tree. The plain line corresponds to the mean speciation rate from the 100 trees, and dashed lines correspond to the 95% confidence interval. The figure was generated with R (https://cran.r-project.org/).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5384087&req=5

f5: Speciation rate through time estimated by the best fitting model of diversification (Table 4).The model was fitted on the MCC tree and on 100 trees. The dotted line corresponds to the speciation rate of the MCC tree. The plain line corresponds to the mean speciation rate from the 100 trees, and dashed lines correspond to the 95% confidence interval. The figure was generated with R (https://cran.r-project.org/).
Mentions: We first investigated heterogeneity among clades for speciation and extinction rates using MEDUSA48 on the MCC tree and on 100 trees from the posterior distribution. No significant shift of diversification rates was found on the MCC tree. Five trees of the posterior distribution (5%) had at least one significant shift of diversification rates. Each of those shifts was found in less than 5% of the trees, and therefore considered as non-significant. We then investigated whether diversification rates varied through time by fitting time-dependent models of speciation and extinction rates49. The best fitting model was an exponential time-dependent speciation rate without extinction (Table 4). According to this model speciation rate decreased from 0.646 event per lineage per million year for the MCC tree and 0.538 ± 0.024 for the 100 trees at the origin of the genus (crown) to 0.148 for the MCC tree and 0.159 ± 0.002 for the 100 trees at present (Fig. 5). All other models, including the constant speciation rate model, were rejected at the threshold of ΔAIC > 2, strengthening the support for a decreasing speciation rate through time.

View Article: PubMed Central - PubMed

ABSTRACT

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.

No MeSH data available.