23 research outputs found
Facultative parthenogenesis: a transient state in transitions between sex and obligate asexuality in stick insects?
Facultative parthenogenesis: a transient state in transitions between sex and obligate asexuality in stick insects?
Turning body and self inside out: visualized heartbeats alter bodily self-consciousness and tactile perception
Prominent theories highlight the importance of bodily perception for self-consciousness, but it is currently not known whether bodily perception is based on interoceptive or exteroceptive signals or on integrated signals from these anatomically distinct systems. In the research reported here, we combined both types of signals by surreptitiously providing participants with visual exteroceptive information about their heartbeat: A real-time video image of a periodically illuminated silhouette outlined participants' (projected, "virtual") bodies and flashed in synchrony with their heartbeats. We investigated whether these "cardio-visual" signals could modulate bodily self-consciousness and tactile perception. We report two main findings. First, synchronous cardio-visual signals increased self-identification with and self-location toward the virtual body, and second, they altered the perception of tactile stimuli applied to participants' backs so that touch was mislocalized toward the virtual body. We argue that the integration of signals from the inside and the outside of the human body is a fundamental neurobiological process underlying self-consciousness
Facultative parthenogenesis: a transient state in transitions between sex and obligate asexuality in stick insects?
Genomic Evidence for Cryptic Speciation in Tree Frogs From the Apennine Peninsula, With Description of Hyla perrini sp. nov
Despite increasing appreciation of the speciation continuum, delimiting and describing new species is a major yet necessary challenge of modern phylogeography to help optimize conservation efforts. In amphibians, the lack of phenotypic differences between closely-related taxa, their complex, sometimes unresolved phylogenetic relationships, and their potential to hybridize all act to blur taxonomic boundaries. Here we implement a multi-disciplinary approach to evaluate the nature of two deeply-diverged mitochondrial lineages previously documented in Italian tree frogs (Hyla intermedia s. l.), distributed north and south of the Northern Apennine Mountains. Based on evidence from mitochondrial phylogenetics, nuclear phylogenomics, hybrid zone population genomics, niche modeling analyses, and biometric assessments, we propose that these lineages be considered distinct, cryptic species. Both mitochondrial and nuclear data affirm that they belong to two monophyletic clades of Pliocene divergence (~3.5 My), only admixing over a relatively narrow contact zone restricted to the southeast of the Po Plain (50–100 km). These characteristics are comparable to similarly-studied parapatric amphibians bearing a specific status. Inferred from their current geographic distribution, the two Italian tree frogs feature distinct ecological niches (<15% of niche overlap), raising questions regarding potential adaptive components contributing to their incipient speciation. However, we found no diagnostic morphological and bioacoustic differences between them. This system illustrates the speciation continuum of Western-Palearctic tree frogs and identifies additional cryptic lineages of similar divergence to be treated as separate species (H. cf. meridionalis). We recommend combined approaches using genomic data as applied here for the future taxonomic assessment of cryptic diversity in alloparapatric radiations of terrestrial vertebrates, especially in controversial taxa. Finally, we formally described the northern Italian tree frogs as a new species, Hyla perrini sp. nov
Buccal swabs: a universal alternative to sample bird DNA
Least intrusive sampling should be prioritized for wildlife conservation and bioethics. In birds, DNA samples are typically obtained from blood. Here we emphasized buccal swabs as an alternative source. We tested swabs in adults and nestlings representative of 17 European species (n 189), ranging from small passerines to large Strigiformes (owls) and Larids (gulls), and characterized the extracted DNA yields. The contents were highly variable between and within species, both in terms of quantity and perhaps purity, but the amounts obtained (-100— 10,000 ng) meet the requirements of standard molecular analyses. No differences were found between adults and nestlings. The DNA yields were moderately higher for larger bird species, and samples taken from experienced swabbers yielded more DNA. In line with species-specific case studies that had successfully implemented buccal swabs, our results support the universal potential of the technique, which should be more generally applied in avian research, notably when endangered species are involved
Data from: Identifying homomorphic sex chromosomes from wild-caught adults with limited genomic resources
We demonstrate a genotyping-by-sequencing approach to identify homomorphic sex chromosomes and their homolog in a distantly related reference genome, based on noninvasive sampling of wild-caught individuals, in the moor frog Rana arvalis. Double-digest RADseq libraries were generated using buccal swabs from 30 males and 21 females from the same population. Search for sex-limited markers from the unfiltered data set (411 446 RAD tags) was more successful than searches from a filtered data set (33 073 RAD tags) for markers showing sex differences in heterozygosity or in allele frequencies. Altogether, we obtained 292 putatively sex-linked RAD loci, 98% of which point to male heterogamety. We could map 15 of them to the Xenopus tropicalis genome, all but one on chromosome pair 1, which seems regularly co-opted for sex determination among amphibians. The most efficient mapping strategy was a three-step hierarchical approach, where R. arvalis reads were first mapped to a low-coverage genome of Rana temporaria (17 My divergence), then the R. temporaria scaffolds to the Nanorana parkeri genome (90 My divergence), and finally the N. parkeri scaffolds to the X. tropicalis genome (210 My). We validated our conclusions with PCR primers amplifying part of Dmrt1, a candidate sex determination gene mapping to chromosome 1: a sex-diagnostic allele was present in all 30 males but in none of the 21 females. Our approach is likely to be productive in many situations where biological samples and/or genomic resources are limited
Herps without borders: A new newt case and a review of transalpine alien introductions in Western Europe: Supplementary material
Biogeographic processes have led to different
evolutionary taxa occurring in the northern and southern edges of the Alpine
Mountains in Western Europe. The integrity of this diversity is being
challenged by frequent human-mediated trans-alpine translocations, sometimes
leading to biological invasions. Several alien terrestrial vertebrates of south
Alpine origins (Italy, Swiss Ticino) are causing damages to native north Alpine
fauna. In this paper, we used molecular tools to characterize the understudied
case of the Mediterranean smooth newt (<i>Lissotriton
vulgaris meridionalis</i>) expanding in the outskirts of Geneva since its
introduction before 1975. Mitochondrial and nuclear DNA sequencing suggest that
these exotic populations are a mixture between two diverged<i> L. v. meridionalis </i>lineages from central Italy, and traces of
potential hybridization with the native <i>L.
v. vulgaris</i> was detected. This situation echoes many other trans-alpine
alien introductions. We review all comparable cases of southern to northern
Alps introductions in vertebrates, including seven reptiles and four
amphibians. The majority of south alpine alien lineages were presumably
imported voluntarily by enthusiasts and appear to perform better in the disturbed
habitats found in the anthropogenic landscapes of Western Europe compared to
their native north Alpine counterparts. Most pose serious threats to related
species of similar ecology, through direct competition, predation and
introgressive hybridization. Difficulties to detect alien species on time lead
to significant conservation costs. Better education together with more
appropriate and reactive management plans will be necessary to limit the impact
of future alien introductions