Significant cross-species gene flow detected in the Tamias quadrivittatus group of North American chipmunks

In the past two decades genomic data have been widely used to detect historical gene flow between species in a variety of plants and animals. The Tamias quadrivittatus group of North America chipmunks, which originated through a series of rapid speciation events, are known to undergo massive amounts of mitochondrial introgression. Yet in a recent analysis of targeted nuclear loci from the group, no evidence for cross-species introgression was detected, indicating widespread cytonuclear discordance. The study used heuristic methods that analyze summaries of the multilocus sequence data to detect gene flow, which may suffer from low power. Here we use the full likelihood method implemented in the Bayesian program BPP to reanalyze these data. We take a stepwise approach to constructing an introgression model by adding introgression events onto a well-supported binary species tree. The analysis detected robust evidence for multiple ancient introgression events affecting the nuclear genome, with introgression probabilities reaching 65%. We estimate population parameters and highlight the fact that species divergence times may be seriously underestimated if ancient cross-species gene flow is ignored in the analysis. Our analyses highlight the importance of using adequate statistical methods to reach reliable biological conclusions concerning cross-species gene flow.

It’s All about the Zone: Spider Assemblages in Different Ecological Zones of Levantine Caves

Caves possess a continuum of ecological zones that differ in their microhabitat conditions, resulting in a gradient of nutrients, climate, and illumination. These conditions engender relatively rapid speciation and diverse assemblages of highly specialised spider fauna. It is unclear, however, how zonation of these caves affects spider assemblage composition and structure. Surveys of 35 Levantine caves were conducted to compare the assemblages of spiders between their different ecological zones. The diverse spider assemblages of these caves differed between the entrance, twilight, and dark zones, with troglophiles and accidental species occupying the cave entrance, endemic troglobites occupying the dark zones, and hybrid assemblages existing in the twilight zones. The progression of assemblage composition and divergence throughout cave zones is suggestive of processes of ecological specialisation, speciation, and adaptation of cave-endemic troglobites in the deepest zones of caves, while cave entrance assemblages are composed of relatively common species that can also be found in epigean habitats. Moreover, the cave entrance zone assemblages in our study were similar in the different caves, while the cave dark zone assemblages were relatively distinct between caves. Cave entrance assemblages are a subset of the regional species pool filtered by the cave conditions, while dark zone assemblages are likely a result of adaptations leading to local speciation events.

Conserving Endemic Plant Species in Oceanic Island’s Protected Areas

Oceanic islands are known for their high levels of plant diversity, due to disjunct geographical distribution that leads to speciation. The main factors contributing to genetic speciation includes the creation of a barrier within a previously widely distributed taxon and the limited dispersal of seeds, which favours genetic differentiation and, thus, fosters rapid speciation. Plant survival and population fitness vary according to environmental factors and to human interference. This chapter depicts the importance of oceanic islands as biodiversity hotspots, discusses the threats to which endemic plants on islands are exposed, namely climate change, invasive alien species, urbanisation, touristic activities, fire, changes in agriculture practices and collecting pressure. The best practices worldwide to protect endemic plant species in protected areas are also addressed, namely the implementation of prevention and mitigation actions, the programs executed to protect endemic species, and management plans to avoid future threats.

Understanding Diversity and Systematics in Australian Fabaceae Tribe Mirbelieae

Australia has a very diverse pea-flowered legume flora with 1715 native and naturalised species currently recognised. Tribe Mirbelieae s.l. includes 44% of Australia’s peas in 24 genera with 756 recognised species. However, several genera within the Pultenaea alliance in tribe Mirbelieae are considered to be non-monophyletic and two main options have been proposed: option one is to merge ca. 18 genera containing ca. 540 species (the largest genus, Pultenaea has nomenclatural priority); and option two is to re-circumscribe some genera and describe new genera as required to form monophyletic groups. At the species level, option one would require 76% of names to be changed; whereas based on available data, option two is likely to require, at most, 8.3% of names to change. Option two therefore provides the least nomenclatural disruption but cannot be implemented without a robust phylogenetic framework to define new generic limits. Here we present novel analyses of available plastid DNA data (trnL-F) which suggest that option two would be feasible once sufficient data are generated to resolve relationships. However, the reticulate evolutionary histories or past rapid speciation suggested for this group may prevent the resolution of all nodes. We propose targeted use of Next-Generation Sequencing technology as the best way to resolve relationships between the key clades in the tribe and present a framework for such a study. An overview of current taxonomy in the tribe is presented, along with the state of taxonomic knowledge and availability of published descriptions for electronic flora treatments. Several new combinations and typifications are published in an appendix.

A molecular phylogeny and revision of the genus Pyropteron Newman, 1832 (Lepidoptera, Sesiidae) reveals unexpected diversity and frequent hostplant switch as a driver of speciation

We here revise the genus Pyropteron Newman, 1832 using molecular and morphological analyses. Our data support the monophyly of Pyropteron with Synansphecia Căpușe, 1973 (syn. rev.) being its junior subjective synonym. Four taxa are described as new to science, Pyropteron minianiformis xerxes Bartsch, Pühringer, Lingenhöle & Kallies ssp. nov., Pyropteron hellenicum Bartsch, Pühringer, Lingenhöle & Kallies sp. nov., Pyropteron jordanicum Bartsch, Pühringer, Lingenhöle & Kallies sp. nov. and Pyropteron leucomelaena blaesii Bartsch, Pühringer, Lingenhöle & Kallies ssp. nov., and 4 species are raised to species rank, Pyropteron nigrobarbata (Rebel, 1916) stat. nov., Pyropteron icteropus (Zeller, 1847) stat. rev., Pyropteron euglossaeformis (Lucas, 1849) stat. rev. and Pyropteron erodiiphaga (Dumont, 1922) stat. rev. To stabilize the taxonomy, we designate neotypes for Pyropteron euglossaeformis stat. rev. and Pyropteron ceriaeformis (Lucas, 1849). Pyropteron pipiziformis (Lederer, 1855) comb. nov., is combined with Pyropteron for the first time. The identity of Pyropteron atlantis (Schwingenschuss, 1935), previously confused with Pyropteron borreyi (Le Cerf, 1922) is fixed. We treat Pyropteron muscaeformis lusohispanica Laštůvka & Laštůvka, 2007 syn. nov. as a synonym of Pyropteron koschwitzi (Špatenka, 1992), Pyropteron minianiformis aphrodite Bartsch, 2004 syn. nov. as a synonym of Pyropteron minianiformis destituta (Staudinger, 1894), Pyropteron muscaeformis occidentalis Joannis, 1908 syn. nov. as a synonym of Pyropteron muscaeformis (Esper, 1783), and Sesia lecerfi Oberthür, 1909 syn. nov. is considered a synonym of Bembecia ichneumoniformis ([Denis & Schiffermüller], 1775). Finally, we discuss a model whereby frequent switches in hostplant usage drive rapid speciation in the genus Pyropteron.

Rapid speciation via the evolution of pre-mating isolation in the Iberá Seedeater

Behavioral isolation can catalyze speciation and permit the slow accumulation of additional reproductive barriers between co-occurring organisms. We illustrate how this process occurs by examining the genomic and behavioral bases of pre-mating isolation between two bird species (Sporophila hypoxantha and the recently discovered S. iberaensis) that belong to the southern capuchino seedeaters, a recent, rapid radiation characterized by variation in male plumage coloration and song. Although these two species co-occur without obvious ecological barriers to reproduction, we document behaviors indicating species recognition by song and plumage traits and strong assortative mating associated with genomic regions underlying male plumage patterning. Plumage differentiation likely originated through the reassembly of standing genetic variation, indicating how novel sexual signals may quickly arise and maintain species boundaries.

Biogeographical and evolutionary aspects of a Guineo-Congolian bushcricket tribe: Revision of the genera Cestromoecha Karsch, 1893 and Poreuomena Brunner von Wattenwyl, 1878, with the description of new species (Orthoptera, Tettigoniidae, Phaneropterinae)

The genera Cestromoecha and Poreuomena of the tribe Poreuomenini in Phaneropterinae are revised and new generic characters are given for both genera, and six new species are described in Poreuomena. The newly described species are P. biaculeatasp. nov., P. ealasp. nov., P. gracilicercatasp. nov., P. ivorianasp. nov., P. matthaeisp. nov., and P. tshuapasp. nov. Based on characters defining the two genera, three species so far listed under Cestromoecha are transferred to Poreuomena: P. crassipes Karsch, 1890, P. laeglae (Massa, 2015), and P. magnicerca (Massa, 2013). One species of Cestromoecha, C. mundamensis Karsch, 1896, is synonymised with C. tenuipes (Karsch, 1890) since no morphological differences were detected between the type specimens. Thus, two species remain with Cestromoecha, and Poreuomena now contains 16 species. Morphological closely-related species of Poreuomena suggest rapid speciation in the Congo Basin due to several expansions and shrinkages of the Guineo-Congolian forest belt since the Oligocene. At least two different morphological lineages are discernible. On the other hand the genus Cestromoecha Karsch, 1893 is a species-poor taxon.

Systematics and biology of the Ichnestomina, including new genera and species (Coleoptera: Scarabaeidae, Cetoniinae)

The subtribe Ichnestomina, endemic to southern Africa, exhibits a suite of plesiomorphic features that reflects a particularly old evolutionary age among the Goliathini. Sexual dimorphism is extreme and females are generally brachypterous and unable to fly. Also, adult stages do not feed, and therefore remain active for only a few days after emerging from the soil, devoting all their energy reserves to reproduction. Consequently, populations are range-bound to small areas, often completely isolated on high mountain peaks or ridges, leading to rapid speciation. Results of recent investigations and historical data are hereby combined to provide an updated and revised structure of the systematics of this subtribe. As a result, four genera are now recognised in place of the perceived uniformity earlier expressed with much reservation by Holm (1992). This involves the rehabilitation of the original name of Gariep Gory & Percheron, 1833, to accommodate species with fully winged and flying females as well as elongate and incision-free dorsal lobes of parameres (Gariep patera and G. perstriata. It is further proposed that the genus Ichnestoma Gory & Percheron, 1833 be restricted to species with moderate female brachyptery and males with cretaceous markings on their body surface. Consequently, two new genera are erected (Karooida gen. nov., Mzansica gen. nov.) and four species-complexes (Ichnestoma cuspidata, I. albomaculata, Mzansica nasula and M. luridipennis), are added in order to account for key differences among species, including degree of female brachyptery (wing:elytron length ratio), presence/absence of cretaceous markings, aedeagal structure and biogeographic distribution. Eleven new species (Ichnestoma carbonaria sp. nov., I. dealbata sp. nov., I. furcata sp. nov., I. karoominoris sp. nov., I. spatulata sp. nov., Karooida balli sp. nov., K. sagittata sp. nov., Mzansica botswanica sp. nov., M. clarki sp. nov., M. denticulata sp. nov., M. falcipata sp. nov.) are added to the 13 species and three subspecies currently recognised in this subtribe. The three subspecies are elevated to species status (Ichnestoma cochleata stat. nov., I. fuscipennis stat. nov., Karooida kikvorsti comb. et stat. nov.). The diagnostic characters of each taxon are described along with all available knowledge on the habitat characteristics and general biology of each species.