Unveiling the roles of interspecific competition and local adaptation in phenotypic differentiation of parapatric frogs

Understanding how ecological processes affect phenotypic evolution has been and continues to be an important goal of ecology and evolutionary biology. Interspecific competition for resources can be a selective force driving phenotypic differentiation that reduces competition among sympatric species (character divergence), enabling closely-related species to coexist. However, although patterns of character divergence are well documented in both empirical and theoretical researches, how local adaptation to abiotic environment affects trait evolution in the face of interspecific competition is less known. Here, we investigate how patterns in morphological traits of 2 parapatric frog species, Feirana quadranus and F. taihangnica, vary among allopatric and sympatric regions using range-wide data derived from extensive field surveys. Feirana quadranus was overall larger than F. taihangnica in body size (i.e., snout–vent length [SVL]), and the difference between SVL of both species in sympatry was larger than that in allopatry. From allopatry to sympatry, the 2 species diverged in foot and hand traits, but converged in eye size and interorbital span, even when we controlled for the effects of geographic gradients. Sympatric divergence in SVL, hand and foot traits is likely acting as a case of evolutionary shift caused by interspecific competition. In contrast, sympatric convergence of eye-related traits may derive at least partly from adaptation to local environments. These results imply the relative roles of interspecific competition and local adaptation in shaping phenotypic diversification. Our findings illustrate how traits evolve in parapatric species pair due to sympatric divergent and convergent evolution. It thus provides insights into understanding underlying evolutionary processes of parapatric species, that is, competition and local adaptation.

Facets of phylodiversity: evolutionary diversification, divergence and survival as conservation targets

Biodiversity is often described as having multiple facets, including species richness, functional diversity and phylogenetic diversity. In this paper, we argue that phylogenetic diversity itself has three distinct facets—lineage diversification, character divergence and survival time—that can be quantified using distinct branch length metrics on an evolutionary tree. Each dimension is related to different processes of macroevolution, has different spatial patterns and is tied to distinct goals for conserving biodiversity and protecting its future resilience and evolutionary potential. We compared the landscapes identified as top conservation priorities by each of these three metrics in a conservation gap analysis for California, a world biodiversity hotspot, using herbarium data on the biogeography and evolutionary relationships of more than 5000 native plant species. Our analysis incorporated a novel continuous metric of current land protection status, fine-scale data on landscape intactness and an optimization algorithm used to identify complementary priority sites containing concentrations of taxa that are evolutionarily unique, vulnerable due to small range size and/or poorly protected across their ranges. Top conservation priorities included pockets of coastal and northern California that ranked highly for all three phylodiversity dimensions and for species richness, as well as sites uniquely identified by each metric whose value may depend on whether properties such as genetic divergence, high net diversification or independent survival experience are most desirable in an Anthropocene flora. This article is part of the theme issue ‘Biological collections for understanding biodiversity in the Anthropocene’.

Comparative exploration of antennae in Pseudopontia, and antennal clubs of the tribes Leptideini and Dismorphiini (Lepidoptera: Pieridae)

We examined antennal ultrastructure in species of Dismorphiinae and Pseudopontiinae (Pieridae) using scanning electron microscopy (SEM). We examined two species of Pseudopontia (Pseudopontiinae) and more than 30 species in seven genera of two tribes in the subfamily Dismorphiinae: Leptidea, Enantia, Pseudopieris, Lieinix, Moschoneura, Dismorphia, and Patia. We focused on the scaleless terminal area of the antenna where there are many types of sensilla, some of which are clustered together and constitute specialized organs. We measured, described, and illustrate at different magnifications structures including the antennal club, antennomeres, sulci, pseudosulci, and chaetic, trichoid, coeloconic, basiconic, and auriculate sensilla, as well as other previously unnamed sensilla. From these antennal features, we created a matrix of characters that allowed us to recognize divergence between the tribes Leptideini and Dismorphiini. The antennae of Leptideini have fewer scaleless antennomeres in the antennal club than those of Dismorphiini, a greater number of pseudosulci disaggregated or dispersed (in Leptidea), and fewer types of sensilla and microtrichia (a more homogeneous antennal morphology), as well as a reduction in the density of sensilla. In Leptidea the antennal form is more specialized: it is shorter in comparison to genera of other Papilionoidea families. We also created a matrix of general morphological characters of Dismorphiinae and Pieridae from the taxonomic literature. This matrix confirms the marked character divergence between the tribes and allows for a more meaningful discussion regarding the relationships between Dismorphiinae and the other subfamilies of Pieridae (i.e., Pseudopontiinae, Coliadinae, and Pierinae). We argue that Pseudopontiinae cannot be considered the least derived subfamily among Pieridae because pupal features, wing venation, and antennal characters exhibit a combination of primitive and specialized states. In addition, we discuss our results from the perspective of patterns of food plant usage in pierid subfamilies, specifically the diversification of several Dismorphiinae genera on Hologalegina and Ingeae (Fabaceae).

Esophyllas, a new genus of erigonine spiders from southern California (Araneae: Linyphiidae: Erigoninae)

We erect a new genus, Esophyllas n. gen., to place two litter dwelling species of erigonine spiders from southern Califor-nia the type species, E. vetteri n. sp. and E. synankylis n. sp. A detailed genus diagnosis is presented as well as compre-hensive morphological descriptions, artist illustrations, and SEM images for each species. We also provide data on habitataffinities, phenology, and distribution, including a distribution map figure. For tentative phylogenetic placement both spe-cies were scored for the characters in the data matrix of Miller & Hormiga (2004) and subsequently entered into the ex-panded matrix of Frick et al. (2010). The analysis places Esophyllas n. gen. within the “distal erigonines” as sister toScirites Bishop and Crosby in a polytomy with Tapinocyba Simon 1884 and Abacoproeces (L. Koch). Data from morpho-logical comparisons with taxa not included in the expanded matrix do not strongly support these relationships but insteadsuggest that Esophyllas n. gen. is more closely related to Phlattothrata parva (Kulczyn’ski 1926). However, in light ofthe extent of character divergence from the above genera we contend that the true sister group to Esophyllas n. gen. either has not yet been described or is among the vast number of phylogenetically untested taxa.

Genetic parameters and variability in physic nut accessions during early developmental stages

The objective of this work was to estimate the genetic parameters and variability among accessions (half-sib families) of physic nut (Jatropha curcas) during the early stages of development. For this study, 110 accessions in the first year of development of the physic nut germplasm bank, maintained at Embrapa Cerrados, DF, Brazil, were evaluated in situ. The experiment was established in a randomized complete block design, with two replicates and five plants per plot arranged in rows at 4x2 m spacing. Grain yield, total number of branches per plant, plant height, stem diameter, canopy projection on the row, canopy projection between rows, canopy volume, number of days until first flowering and height of the first inflorescence were evaluated. Estimates of vegetative genetic parameters showed the existence of genetic variability in the physic nut germplasm bank. Physic nut accessions of the germplasm bank were grouped into five similarity groups based on character divergence. Although preliminary, the obtained results are promising for showing potential for Jatropha improvement with selective efficiency.