Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 27
Filter
1.
Nature ; 628(8009): 811-817, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38632397

ABSTRACT

Hybridization allows adaptations to be shared among lineages and may trigger the evolution of new species1,2. However, convincing examples of homoploid hybrid speciation remain rare because it is challenging to demonstrate that hybridization was crucial in generating reproductive isolation3. Here we combine population genomic analysis with quantitative trait locus mapping of species-specific traits to examine a case of hybrid speciation in Heliconius butterflies. We show that Heliconius elevatus is a hybrid species that is sympatric with both parents and has persisted as an independently evolving lineage for at least 180,000 years. This is despite pervasive and ongoing gene flow with one parent, Heliconius pardalinus, which homogenizes 99% of their genomes. The remaining 1% introgressed from the other parent, Heliconius melpomene, and is scattered widely across the H. elevatus genome in islands of divergence from H. pardalinus. These islands contain multiple traits that are under disruptive selection, including colour pattern, wing shape, host plant preference, sex pheromones and mate choice. Collectively, these traits place H. elevatus on its own adaptive peak and permit coexistence with both parents. Our results show that speciation was driven by introgression of ecological traits, and that speciation with gene flow is possible with a multilocus genetic architecture.


Subject(s)
Butterflies , Genetic Introgression , Genetic Speciation , Hybridization, Genetic , Quantitative Trait Loci , Animals , Female , Male , Butterflies/anatomy & histology , Butterflies/classification , Butterflies/genetics , Gene Flow , Genetic Introgression/genetics , Genome, Insect/genetics , Mating Preference, Animal , Phenotype , Pigmentation/genetics , Quantitative Trait Loci/genetics , Reproductive Isolation , Selection, Genetic/genetics , Species Specificity , Sympatry/genetics , Wings, Animal/anatomy & histology , Wings, Animal/metabolism
2.
J Hered ; 115(1): 130-138, 2024 Feb 03.
Article in English | MEDLINE | ID: mdl-37793045

ABSTRACT

The little pocket mouse, Perognathus longimembris, and its nine congeners are small heteromyid rodents found in arid and seasonally arid regions of Western North America. The genus is characterized by behavioral and physiological adaptations to dry and often harsh environments, including nocturnality, seasonal torpor, food caching, enhanced osmoregulation, and a well-developed sense of hearing. Here we present a genome assembly of Perognathus longimembris longimembris generated from PacBio HiFi long read and Omni-C chromatin-proximity sequencing as part of the California Conservation Genomics Project. The assembly has a length of 2.35 Gb, contig N50 of 11.6 Mb, scaffold N50 of 73.2 Mb, and includes 93.8% of the BUSCO Glires genes. Interspersed repetitive elements constitute 41.2% of the genome. A comparison with the highly endangered Pacific pocket mouse, P. l. pacificus, reveals broad synteny. These new resources will enable studies of local adaptation, genetic diversity, and conservation of threatened taxa.


Subject(s)
Chromosomes , Genome , Animals , Mice , Genomics , North America
3.
Pol Przegl Chir ; 96(2): 11-20, 2023 Oct 12.
Article in English | MEDLINE | ID: mdl-38629281

ABSTRACT

<br><b>Introduction:</b> The use of meshes in mastectomies with immediate breast reconstruction (IBR) has become the gold standard.</br> <br><b>Aim:</b> The use of meshes in mastectomies with immediate breast reconstruction (IBR) has become a gold standard. The purpose of the study was to analyze the complications and own experience with the use of Serasynth fully absorbable and SeragynBR partially absorbable synthetic meshes.</br> <br><b>Material and methods:</b> In the period from December 2017 to July 2020, 118 IBR were performed in the Author's Department with the use of SeragynBR and Serasynth meshes in 93 patients operated for breast cancer. 78 Serasynth meshes (Group 1) and 40 SeragynBR meshes (Group 2) were implanted.</br> <br><b>Results:</b> The most common complication was persistent seroma collection, which was reported in 17.9% of cases in Group 1 and 25% in Group 2. Skin inflammation was reported in 7.6% and 17.5%, while infections in 2.5% and 5% of the operated breasts in Group 1 and Group 2. Reoperation was required in 5.1% and 5% of the patients in Group 1 and Group 2. The percentage of complications was lower when Serasynth rather than Seragyn BR meshes were implanted. The frequent incidence of the seroma collection did not contribute in any significant way to serious complications such as removal of mesh/implant or infection. The complications, which developed following the implantation of both mesh types, were similar to those presented in other publications concerning mastectomy with IBR with the use of synthetic meshes. The percentage of implant losses/explanations in the discussed groups was lower than that reported in the literature.</br> <br><b>Conclusion:</b> Despite the complications, both types of meshes can be considered as safe additions to reconstructive breast surgeries.</br> <br><b>Level of Evidence:</b> Level III.</br>.


Subject(s)
Breast Neoplasms , Mammaplasty , Plastic Surgery Procedures , Humans , Female , Breast Neoplasms/surgery , Seroma/etiology , Mastectomy , Mammaplasty/adverse effects
4.
Nat Commun ; 13(1): 4676, 2022 08 09.
Article in English | MEDLINE | ID: mdl-35945236

ABSTRACT

Repeated evolution can provide insight into the mechanisms that facilitate adaptation to novel or changing environments. Here we study adaptation to altitude in two tropical butterflies, Heliconius erato and H. melpomene, which have repeatedly and independently adapted to montane habitats on either side of the Andes. We sequenced 518 whole genomes from altitudinal transects and found many regions differentiated between highland (~ 1200 m) and lowland (~ 200 m) populations. We show repeated genetic differentiation across replicate populations within species, including allopatric comparisons. In contrast, there is little molecular parallelism between the two species. By sampling five close relatives, we find that a large proportion of divergent regions identified within species have arisen from standing variation and putative adaptive introgression from high-altitude specialist species. Taken together our study supports a role for both standing genetic variation and gene flow from independently adapted species in promoting parallel local adaptation to the environment.


Subject(s)
Butterflies , Adaptation, Physiological/genetics , Altitude , Animals , Butterflies/genetics , Phenotype , Phylogeny
5.
Article in English | MEDLINE | ID: mdl-35409936

ABSTRACT

Exposure to radon is the second most common factor causing lung cancer in smokers and the first among non-smokers. We aimed to measure the impact of the radon exposure on patients with different histological types of advanced lung cancer. The measurement of radon exposure was performed in 102 patients with lung cancer in stage 3B or higher (Poland). There were 78.4% of patients with non-small cell carcinoma and 21.6% of patients with small cell carcinoma. One month radon exposure measurement was performed with trace detectors in order to control whether high radon concentrations (>800 Bq/m3) were found in the homes of patients with cancer diagnosed. Results of the determinations were then compared with the representation of the most common types of lung cancer in the study population. In the analyzed group, the average concentration of radon during the exposure of the detector in the residential premises of the respondents accounted for 69.0 Bq/m3 [37.0−117.0] and had no statistically significant effect on the type of lung cancer developed in patients. The lack of statistical significance may result from the small study group and the accompanying exposure to other harmful components. As the incidence of lung adenocarcinoma is increasing and exposure to tobacco smoke is decreasing, the search for other modifiable causes of lung cancer should be the task in the future.


Subject(s)
Lung Neoplasms , Neoplasms, Radiation-Induced , Radon , Case-Control Studies , Environmental Exposure/adverse effects , Housing , Humans , Lung Neoplasms/chemically induced , Lung Neoplasms/etiology , Neoplasms, Radiation-Induced/epidemiology , Poland/epidemiology , Radon/analysis
6.
Genome Biol Evol ; 13(7)2021 07 06.
Article in English | MEDLINE | ID: mdl-33944917

ABSTRACT

How frequent is gene flow between species? The pattern of evolution is typically portrayed as a phylogenetic tree, yet gene flow between good species may be an important mechanism in diversification, spreading adaptive traits and leading to a complex pattern of phylogenetic incongruence. This process has thus far been studied mainly among a few closely related species, or in geographically restricted areas such as islands, but not on the scale of a continental radiation. Using a genomic representation of 40 out of 47 species in the genus, we demonstrate that admixture has played a role throughout the evolution of the charismatic Neotropical butterflies Heliconius. Modeling of phylogenetic networks based on the exome uncovers up to 13 instances of interspecific gene flow. Admixture is detected among the relatives of Heliconius erato, as well as between the ancient lineages leading to modern clades. Interspecific gene flow played a role throughout the evolution of the genus, although the process has been most frequent in the clade of Heliconius melpomene and relatives. We identify Heliconius hecalesia and relatives as putative hybrids, including new evidence for introgression at the loci controlling the mimetic wing patterns. Models accounting for interspecific gene flow yield a more complete picture of the radiation as a network, which will improve our ability to study trait evolution in a realistic comparative framework.


Subject(s)
Butterflies , Animals , Butterflies/genetics , Gene Flow , Genome , Phylogeny , Wings, Animal
7.
J Gastrointest Cancer ; 52(2): 476-488, 2021 Jun.
Article in English | MEDLINE | ID: mdl-33761051

ABSTRACT

PURPOSE: Recent studies have suggested that molecular targets for the anti-angiogenic therapy might constitute a basis for additional therapy in gastric cancer treatment. A vast number of molecules, receptors, pathways, specific interactions, and thus strategies that target gastric cancer angiogenesis specifically have been reported in numerous research articles and clinical trials. METHODS: We conducted a systematic literature review of molecularly targeted treatment strategies in gastric cancer on the following databases-PubMed, Google Scholar, and Scopus-on September 20, 2020. Multiple articles and evaluations were searched for studies reporting newly found and promising molecular anti-angiogenic therapy pathways. Eventually, 39 articles regarding the anti-angiogenic therapy in gastric cancer were included in the final analysis. RESULTS: As a consequence of the release of the pro-angiogenic molecules from the tumour cells, gastric cancer presents high angiogenic capability. Therefore, potential schemes for future treatment strategies include the decrease of the process ligands as well as the expression of their receptors. Moreover, the increase in the angiogenic inhibitor levels and direct aim for the inner walls of the endothelial cells appear as a promising therapeutic strategy. Beyond that, angiogenesis process inhibition seems to indirectly exaggerate the effects of chemotherapy in the considered patients. CONCLUSIONS: The anti-angiogenic treatment in gastric cancer patients evaluates its significance especially in the early stages of the malignancy. The studies conducted so far show that most of the meaningful angiogenic factors and receptors with the potential molecular pathways should be further evaluated since they could potentially play a substantial role in future therapies.


Subject(s)
Angiogenesis Inhibitors/pharmacology , Stomach Neoplasms/drug therapy , Antineoplastic Agents , Humans , Molecular Targeted Therapy/methods , Stomach Neoplasms/surgery
8.
Toxics ; 8(4)2020 Dec 14.
Article in English | MEDLINE | ID: mdl-33327615

ABSTRACT

Lung cancer is a heterogeneous group of diseases with multifactorial aetiology. Smoking has been undeniably recognized as the main aetiological factor in lung cancer, but it should be emphasized that it is not the only factor. It is worth noting that a number of nonsmokers also develop this disease. Radon exposure is the second greatest risk factor for lung cancer among smokers-after smoking-and the first one for nonsmokers. The knowledge about this element amongst specialist oncologists and pulmonologists seems to be very superficial. We discuss the impact of radon on human health, with particular emphasis on respiratory diseases, including lung cancer. A better understanding of the problem will increase the chance of reducing the impact of radon exposure on public health and may contribute to more effective prevention of a number of lung diseases.

9.
Proc Biol Sci ; 287(1937): 20201071, 2020 10 28.
Article in English | MEDLINE | ID: mdl-33081613

ABSTRACT

Studies of altitudinal and latitudinal gradients have identified links between the evolution of insect flight morphology, landscape structure and microclimate. Although lowland tropical rainforests offer steeper shifts in conditions between the canopy and the understorey, this vertical gradient has received far less attention. Butterflies, because of their great phenotypic plasticity, are excellent models to study selection pressures that mould flight morphology. We examined data collected over 5 years on 64 Nymphalidae butterflies in the Ecuadorian Chocó rainforest. We used phylogenetic methods to control for similarity resulting from common ancestry, and explore the relationships between species stratification and flight morphology. We hypothesized that species should show morphological adaptations related to differing micro-environments, associated with canopy and understorey. We found that butterfly species living in each stratum presented significantly different allometric slopes. Furthermore, a preference for the canopy was significantly associated with low wing area to thoracic volume ratios and high wing aspect ratios, but not with the relative distance to the wing centroid, consistent with extended use of fast flapping flight for canopy butterflies and slow gliding for the understorey. Our results suggest that microclimate differences in vertical gradients are a key factor in generating morphological diversity in flying insects.


Subject(s)
Butterflies/physiology , Flight, Animal , Rainforest , Adaptation, Physiological , Animals , Biological Evolution , Wings, Animal
10.
Ecol Evol ; 10(9): 3895-3918, 2020 May.
Article in English | MEDLINE | ID: mdl-32489619

ABSTRACT

In many animals, mate choice is important for the maintenance of reproductive isolation between species. Traits important for mate choice and behavioral isolation are predicted to be under strong stabilizing selection within species; however, such traits can also exhibit variation at the population level driven by neutral and adaptive evolutionary processes. Here, we describe patterns of divergence among androconial and genital chemical profiles at inter- and intraspecific levels in mimetic Heliconius butterflies. Most variation in chemical bouquets was found between species, but there were also quantitative differences at the population level. We found a strong correlation between interspecific chemical and genetic divergence, but this correlation varied in intraspecific comparisons. We identified "indicator" compounds characteristic of particular species that included compounds already known to elicit a behavioral response, suggesting an approach for identification of candidate compounds for future behavioral studies in novel systems. Overall, the strong signal of species identity suggests a role for these compounds in species recognition, but with additional potentially neutral variation at the population level.

11.
Ecol Evol ; 10(5): 2677-2694, 2020 Mar.
Article in English | MEDLINE | ID: mdl-32185010

ABSTRACT

Evolutionary convergence of color pattern in mimetic species is tightly linked with the evolution of chemical defenses. Yet, the evolutionary forces involved in natural variations of chemical defenses in aposematic species are still understudied. Herein, we focus on the evolution of chemical defenses in the butterfly tribe Heliconiini. These neotropical butterflies contain large concentrations of cyanogenic glucosides, cyanide-releasing compounds acting as predator deterrent. These compounds are either de novo synthesized or sequestered from their Passiflora host plant, so that their concentrations may depend on host plant specialization and host plant availability. We sampled 375 wild Heliconiini butterflies across Central and South America, covering 43% species of this clade, and quantify individual variations in the different CGs using liquid chromatography coupled with tandem mass spectrometry. We detected new compounds and important variations in chemical defenses both within and among species. Based on the most recent and well-studied phylogeny of Heliconiini, we show that ecological factors such as mimetic interactions and host plant specialization have a significant association with chemical profiles, but these effects are largely explained by phylogenetic relationships. Our results therefore suggest that shared ancestries largely contribute to chemical defense variation, pointing out at the interaction between historical and ecological factors in the evolution of Müllerian mimicry.

12.
J Environ Radioact ; 188: 87-94, 2018 Aug.
Article in English | MEDLINE | ID: mdl-29021085

ABSTRACT

In this work a hand-held spectrometer InSpector 1000 with NaI (Tl) 2″ x 2″ detector has been adapted to fast in situ gamma-ray spectroscopy. Two specially designed mounting stands with shielding have been built, allowing conducting measurements in different geometries. Three particular geometries (NW, IS50, IS00) have been chosen for efficiency calibration and further study. The first one (NW) is intended for small environmental samples (volume ca 140 cm3) collected on site. IS50 geometry is a typical in situ geometry meant for radioactivity measurements in soil with detector pointed towards the ground. In this geometry the probe is shielded and mounted 50 cm above the soil surface. The new proposed geometry IS00 is designed in the way that the detector is inserted directly into the soil in order to increase the counting efficiency. The methods of efficiency calibration involved using calibration standards (in NW geometry) and the results obtained in previous in situ measurements with InSpector 2000 portable spectrometer with HPGe detector and ISOCS™ Shield Systems, which is routinely used in environmental measurements. NW geometry turned out to be useful for natural radioisotopes concentrations (K-40, U-238 and Th-232), which significantly exceed typical values of those concentrations observed in Poland. Both IS50 and IS00 geometries are applicative for quick (2 h long measurement) evaluation of typical concentrations of K, U and Th in soils. The newly proposed geometry IS00 is superior as it showed lower detection limits and uncertainties as well as its handling was far easier than of IS50. Authors have proven that hand-held spectrometer InSpector 1000, together with mounting stands and shielding, can be successfully used for fast in situ gamma-spectroscopy. Its relatively small weight and good mobility are additional assets. Moreover, detailed procedures for measurements in each geometry have been developed to conduct such analyses properly.


Subject(s)
Radiation Monitoring/instrumentation , Radioisotopes/analysis , Spectrometry, Gamma/methods , Calibration , Poland , Radioactive Pollutants/analysis , Sodium Iodide/chemistry
13.
J Environ Radioact ; 188: 95-99, 2018 Aug.
Article in English | MEDLINE | ID: mdl-29029764

ABSTRACT

ISOCS (In Situ Counting Object System) from Canberra is applied in laboratory for creating efficiency calibrations of good quality without using radioactive standards. Besides of typical sample containers used in laboratory, ISOSC system also allows modelling containers and objects of almost any shape and elemental composition. The study was based on gamma spectrometry with HPGe semiconductor detector with electronics and software spectrum analysis GENIE 2000 + ISOCS. Measuring set is equipped with portable shield system with set of collimators ISOCS Shield Systems Model ISOXSHLD from Canberra. This shielding system provides attenuation of gamma background radiation with average value 33 (for gamma energies from 186 keV to 2615.5 keV). The portable shield system can be used for low-background laboratory measurements. For this purpose a measuring vessel of new geometry was constructed: the polystyrene cylinder with a height of 40 mm and a diameter of 70 mm. The efficiency calibration for this container was performed using both ISOCS system and classical calibration standard in the same geometry. In order to verify the correctness of performed calibration procedures, the measurements of radioactive standard CBSS 2 were made. The results of both calibrations were compared with the data from the standard certificate. Satisfactory agreement was achieved. Mean percentage difference between results from ISOCS calibration compared to reference values is 6% for all isotopes activities in CBSS 2 standard. The set of collimators was used to develop efficiency calibration for in situ measurements of the soil surface. Test measurements were carried out at the area of the Institute of Nuclear Physics Polish Academy of Sciences in Kraków, Poland (IFJ PAN). Two measurement methods were compared: in situ and laboratory gamma spectroscopy. The obtained average results (from all 10 measuring points) are consistent within the range of measurement uncertainty.


Subject(s)
Radiation Monitoring/methods , Spectrometry, Gamma/methods , Background Radiation , Calibration , Germanium/analysis , Laboratories , Software , Uncertainty
14.
Radiat Prot Dosimetry ; 177(1-2): 95-98, 2017 Nov 01.
Article in English | MEDLINE | ID: mdl-29036677

ABSTRACT

The measurements of radon concentration were carried out in kindergartens of V4 countries (Hungary, Poland and Slovakia). RSKS detectors (Radosys Ltd., Hungary) were used for integrating measurement in indoor air. In total, 67 rooms in 20 kindergartens were measured. The survey was carried out in two periods from October 2015 to March 2016. The results show that radon concentration is less than 300 Bq m-3 in approximately 86.0% of cases in the first period and in 82.1% of cases in second period. However, rooms in kindergartens with radon concentration exceeding 1000 Bq m-3 were found in Slovakia.


Subject(s)
Air Pollutants, Radioactive/analysis , Air Pollution, Indoor/analysis , Radiation Monitoring/methods , Schools , Child, Preschool , Female , Humans , Hungary , Male , Poland , Radon/analysis , Slovakia
15.
Evolution ; 71(2): 261-273, 2017 02.
Article in English | MEDLINE | ID: mdl-27958661

ABSTRACT

Understanding both the role of selection in driving phenotypic change and its underlying genetic basis remain major challenges in evolutionary biology. Here, we use modern tools to revisit a classic system of local adaptation in the North American deer mouse, Peromyscus maniculatus, which occupies two main habitat types: prairie and forest. Using historical collections, we find that forest-dwelling mice have longer tails than those from nonforested habitat, even when we account for individual and population relatedness. Using genome-wide SNP data, we show that mice from forested habitats in the eastern and western parts of their range form separate clades, suggesting that increased tail length evolved independently. We find that forest mice in the east and west have both more and longer caudal vertebrae, but not trunk vertebrae, than nearby prairie forms. By intercrossing prairie and forest mice, we show that the number and length of caudal vertebrae are not correlated in this recombinant population, indicating that variation in these traits is controlled by separate genetic loci. Together, these results demonstrate convergent evolution of the long-tailed forest phenotype through two distinct genetic mechanisms, affecting number and length of vertebrae, and suggest that these morphological changes-either independently or together-are adaptive.


Subject(s)
Biological Evolution , Peromyscus/anatomy & histology , Peromyscus/genetics , Phenotype , Tail/anatomy & histology , Animals , DNA, Mitochondrial/genetics , Forests , Grassland , North America , Phylogeography , Sequence Analysis, DNA
16.
Microsc Res Tech ; 80(1): 131-143, 2017 Jan.
Article in English | MEDLINE | ID: mdl-27859863

ABSTRACT

Our aim was to study the influence of low doses (0.2-4 µGy) of α radiation on the stability of human erythrocytes isolated from healthy and diabetic erythrocytes. Absorption spectroscopy was used to measure the level of red blood cell (RBC) hemolysis, along with Mössbauer spectroscopy, which is a highly specific method suited to monitoring various hemoglobin forms. States of hemoglobin are sensitive to a homeostatic imbalance in red blood cells. Changes in the membrane skeleton organization of irradiated erythrocytes isolated from healthy donors were studied using atomic force microscopy (AFM). Hemolysis, in healthy red blood cells, showed characteristic discontinuities, depending on the α particle flux and the exposure time to the low doses applied. This phenomenon was not observed in severe diabetic cases, which could be a result of modified protein-lipid-sugar complexes and the attenuation/absence of some antioxidative enzymatic processes in their RBC membranes. Similar effects were also observed for red blood cells treated with low doses of neutron and γ-radiation. AFM measurements demonstrated a reorganization of the RBC membrane skeleton network depending on the time of RBC exposure to α radiation. This suggests that the changes in the activity of the acute defense processes against free radicals which are activated within the erythrocyte membrane irradiated with α-particles could additionally be up- or down regulated by modifications to the membrane-skeleton network. However, even the highest dose of α radiation applied in these studies did not cause any significant changes in the ability of hemoglobin to transport oxygen. Microsc. Res. Tech. 80:131-143, 2017. © 2016 Wiley Periodicals, Inc.


Subject(s)
Alpha Particles , Dose-Response Relationship, Radiation , Erythrocytes/radiation effects , Cells, Cultured , Erythrocyte Membrane/radiation effects , Gamma Rays , Hemoglobins/metabolism , Hemolysis/radiation effects , Homeostasis/drug effects , Humans , Microscopy, Atomic Force
17.
Appl Radiat Isot ; 110: 124-128, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26774389

ABSTRACT

The indoor radon measurements were carried out in 123 residential buildings and 33 schools in Visegrad countries (Slovakia, Hungary and Poland). In 13.2% of rooms radon concentration exceeded 300Bqm(-3), the reference value recommended in the Council Directive 2013/59/EURATOM. Indoor radon in houses shows the typical radon behavior, with a minimum in the summer and a maximum in the winter season, whereas in 32% of schools the maximum indoor radon was reached in the summer months.


Subject(s)
Air Pollutants, Radioactive/analysis , Air Pollution, Indoor/analysis , Radon/analysis , Housing , Humans , Hungary , Poland , Schools , Seasons , Slovakia , Surveys and Questionnaires
18.
BMC Evol Biol ; 15: 125, 2015 Jun 30.
Article in English | MEDLINE | ID: mdl-26123545

ABSTRACT

BACKGROUND: Sympatric speciation is today generally viewed as plausible, and some well-supported examples exist, but its relative contribution to biodiversity remains to be established. We here quantify geographic overlap of sister species of heliconiine butterflies, and use age-range correlations and spatial simulations of the geography of speciation to infer the frequency of sympatric speciation. We also test whether shifts in mimetic wing colour pattern, host plant use and climate niche play a role in speciation, and whether such shifts are associated with sympatry. RESULTS: Approximately a third of all heliconiine sister species pairs exhibit near complete range overlap, and analyses of the observed patterns of range overlap suggest that sympatric speciation contributes 32%-95% of speciation events. Müllerian mimicry colour patterns and host plant choice are highly labile traits that seem to be associated with speciation, but we find no association between shifts in these traits and range overlap. In contrast, climatic niches of sister species are more conserved. CONCLUSIONS: Unlike birds and mammals, sister species of heliconiines are often sympatric and our inferences using the most recent comparative methods suggest that sympatric speciation is common. However, if sister species spread rapidly into sympatry (e.g. due to their similar climatic niches), then assumptions underlying our methods would be violated. Furthermore, although we find some evidence for the role of ecology in speciation, ecological shifts did not show the associations with range overlap expected under sympatric speciation. We delimit species of heliconiines in three different ways, based on "strict and " "relaxed" biological species concepts (BSC), as well as on a surrogate for the widely-used "diagnostic" version of the phylogenetic species concept (PSC). We show that one reason why more sympatric speciation is inferred in heliconiines than in birds may be due to a different culture of species delimitation in the two groups. To establish whether heliconiines are exceptional will require biogeographic comparative studies for a wider range of animal taxa including many more invertebrates.


Subject(s)
Butterflies/classification , Butterflies/genetics , Animals , Biodiversity , Butterflies/anatomy & histology , Climate , Computer Simulation , Databases, Factual , Ecology , Genetic Speciation , Phylogeny , Sympatry , Wings, Animal/anatomy & histology
19.
Syst Biol ; 64(3): 505-24, 2015 May.
Article in English | MEDLINE | ID: mdl-25634098

ABSTRACT

Müllerian mimicry among Neotropical Heliconiini butterflies is an excellent example of natural selection, associated with the diversification of a large continental-scale radiation. Some of the processes driving the evolution of mimicry rings are likely to generate incongruent phylogenetic signals across the assemblage, and thus pose a challenge for systematics. We use a data set of 22 mitochondrial and nuclear markers from 92% of species in the tribe, obtained by Sanger sequencing and de novo assembly of short read data, to re-examine the phylogeny of Heliconiini with both supermatrix and multispecies coalescent approaches, characterize the patterns of conflicting signal, and compare the performance of various methodological approaches to reflect the heterogeneity across the data. Despite the large extent of reticulate signal and strong conflict between markers, nearly identical topologies are consistently recovered by most of the analyses, although the supermatrix approach failed to reflect the underlying variation in the history of individual loci. However, the supermatrix represents a useful approximation where multiple rare species represented by short sequences can be incorporated easily. The first comprehensive, time-calibrated phylogeny of this group is used to test the hypotheses of a diversification rate increase driven by the dramatic environmental changes in the Neotropics over the past 23 myr, or changes caused by diversity-dependent effects on the rate of diversification. We find that the rate of diversification has increased on the branch leading to the presently most species-rich genus Heliconius, but the change occurred gradually and cannot be unequivocally attributed to a specific environmental driver. Our study provides comprehensive comparison of philosophically distinct species tree reconstruction methods and provides insights into the diversification of an important insect radiation in the most biodiverse region of the planet.


Subject(s)
Butterflies/classification , Butterflies/genetics , Genetic Speciation , Phylogeny , Animals , Genetic Markers/genetics , Time
20.
Radiat Prot Dosimetry ; 162(4): 663-73, 2014 Dec.
Article in English | MEDLINE | ID: mdl-24375376

ABSTRACT

Radon and its decay products are harmful pollutants present in indoor air and are responsible for the majority of the effective dose due to ionising radiation that people are naturally exposed to. The paper presents the results of the series of measurements of radon and its progeny (in unattached and attached fractions) as well as indoor air parameters: temperature, relative humidity, number and mass concentrations of fine aerosol particles. The measurements were carried out in the auditorium (lecture hall), which is an indoor air quality laboratory, in controlled conditions during two periods of time: when air conditioning (AC) was switched off (unoccupied auditorium) and when it was switched on (auditorium in normal use). The significant influence of AC and of students' presence on the dynamics of radon and its progeny was confirmed. A decrease in the mean value of radon and its attached progeny was found when AC was working. The mean value of radon equilibrium factor F was also lower when AC was working (0.49) than when it was off (0.61). The linear correlations were found between attached radon progeny concentration and particle number and mass concentration only when the AC was switched off. This research is being conducted with the aim to study the variability of radon equilibrium factor F which is essential to determine the effective dose due to radon and its progeny inhalation.


Subject(s)
Air Conditioning , Air Pollutants, Radioactive/analysis , Air Pollution, Indoor/analysis , Radon Daughters/analysis , Radon/analysis , Air Pollutants, Radioactive/adverse effects , Air Pollution, Indoor/adverse effects , Humans , Poland , Radiation Monitoring , Radon/adverse effects , Radon Daughters/adverse effects , Seasons , Universities
SELECTION OF CITATIONS
SEARCH DETAIL
...