Calicophoron daubneyi (Paramphistomidae) in deer of the Sumava National Park, Czech Republic - Consequence of prevalent rumen fluke infection in cattle.

A substantial parallel increase in prevalence and geographical spread of the rumen fluke, Calicophoron daubneyi, in livestock in western and central Europe has been recognized in the recent past. In the course of the examination of rectum feces of 471 red deer (Cervus elaphus) and one sika deer (Cervus nippon) from the Fascioloides magna endemic Sumava National Park in the years 2021 and 2022, rumen fluke eggs were detected in four red deer (0.8%) and the sika deer and identified as eggs of C. daubneyi by molecular analysis. Subsequent examination of rectal fecal samples of 247 beef cattle from 22 herds of 14 farms located in or nearby the national park revealed rumen fluke eggs in 53 samples (21.5%) originating from 16 herds of 11 farms, molecularly identified as C. daubneyi eggs as well. One C. daubneyi egg positive red deer and three C. daubneyi egg positive cattle samples also contained fasciolid eggs, respectively, which were detected in 9.5% or 3.6% of the total samples from red deer or cattle, respectively. Results of this investigation reveal the first finding of C. daubneyi in sika deer worldwide and in red deer in mainland Europe and add to the growing number of reports on C. daubneyi in livestock in Europe. Considering that the ratio of cattle excreting rumen fluke eggs exceeded that of deer substantially, it can reasonably be assumed that the C. daubneyi infections in deer are a consequence of the prevalent infection in cattle, illustrating a pathogen spillover event from livestock into wildlife.

TB index case tracing in the Roma community in the Czech Republic.

Tuberculosis (TB) contact tracing and TB preventive treatment are key tools in preventing the transmission of TB with the aim of eliminating the disease. Our study seeks to demonstrate how the infection spread from an individual patient to the entire community and how proactive contact tracing facilitated prompt diagnosis and treatment. Our work was conducted as a retrospective analysis of the spread of TB infection within the Roma community in the Czech Republic, following the case of an index patient who succumbed to pulmonary TB. Several levels of care and preventive and treatment measures are outlined. Confirming the identity of the Mycobacterium tuberculosis strain was achieved using molecular methods. Among the 39 individuals examined, TB disease was detected in eight patients and TB infection was detected in six patients. The investigation of contacts within this group yielded positive results in 36% of cases, necessitating treatment. The study's findings provide evidence that actively tracing individuals at risk can lead to early detection of cases, prompt treatment, and prevention of further disease transmission. The study also indicates that the highest risk of infection occurs within the sick person's household and that young children under the age of 5 are most susceptible to falling ill.

Mental health and help-seeking in Czech sexual minorities: a nationally representative cross-sectional study.

AIMS: The mental health of sexual minority (SM) individuals remains overlooked and understudied in Czechia. We aimed to estimate (1) the prevalence rate and (2) the relative risk of common mental disorders and (3) the mental distress severity among the Czech SM people compared with the heterosexual population. In addition, we aimed to investigate help-seeking for mental disorders in SM people. METHODS: We used data from a cross-sectional, nationally representative survey of Czech community-dwelling adults, consisting of 3063 respondents (response rate = 58.62%). We used the Mini-International Neuropsychiatric Interview to assess the presence of mental disorders. In individuals scoring positively, we established help-seeking in the past 12 months. We assessed symptom severity using the 9-item Patient Health Questionnaire and the 7-item Generalized Anxiety Disorder scale. We computed the prevalence of mental disorders and the treatment gap with 95% confidence intervals. To assess the risk of having a mental disorder, we used binary logistic regression. RESULTS: We demonstrated that the prevalence of current mental disorders was 18.85% (17.43-20.28), 52.27% (36.91-67.63), 33.33% (19.5-47.17) and 25.93% (13.85-38) in heterosexual, gay or lesbian, bisexual and more sexually diverse individuals, respectively. Suicidal thoughts and behaviours were present in 5.73% (4.88-6.57), 25.00% (11.68-38.32), 22.92% (10.58-35.25) and 11.11% (2.45-19.77) of heterosexual, gay or lesbian, bisexual and more sexually diverse individuals, respectively. After confounder adjustment, gay or lesbian individuals were more likely to have at least one current mental disorder compared with heterosexual counterparts (odds ratio = 3.51; 1.83-6.76). For bisexual and sexually more diverse individuals, the results were consistent with a null effect (1.85; 0.96-3.45 and 0.89; 0.42-1.73). The mean depression symptom severity was 2.96 (2.81-3.11) in heterosexual people and 4.68 (2.95-6.42), 7.12 (5.07-9.18) and 5.17 (3.38-6.95) in gay or lesbian, bisexual and more sexually diverse individuals, respectively. The mean anxiety symptom severity was 1.97 (1.85-2.08) in heterosexual people and 3.5 (1.98-5.02), 4.63 (3.05-6.2) and 3.7 (2.29-5.11) in gay or lesbian, bisexual and more sexually diverse individuals, respectively. We demonstrated broadly consistent levels of treatment gap in heterosexual and SM individuals scoring positively for at least one current mental disorder (82.91%; 79.5-85.96 vs. 81.13%; 68.03-90.56). CONCLUSIONS: We provide evidence that SM people in Czechia have substantially worse mental health outcomes than their heterosexual counterparts. Systemic changes are imperative to provide not only better and more sensitive care to SM individuals but also to address structural stigma contributing to these health disparities.

Terbinafine resistance in Trichophyton mentagrophytes and Trichophyton rubrum in the Czech Republic: A prospective multicentric study.

BACKGROUND: Terbinafine, an allylamine antifungal, is crucial for treating dermatophytosis by inhibiting squalene epoxidase (SQLE) in the ergosterol biosynthetic pathway. However, resistance is emerging, particularly in India and Southeast Asia, but reports of resistance spread worldwide. Despite this, comprehensive studies on terbinafine resistance in Trichophyton are still limited. OBJECTIVES: This research aimed to determine the prevalence of terbinafine resistance in the Czech Republic, with a focus on Trichophyton rubrum and Trichophyton mentagrophytes, and investigate the underlying molecular mechanisms. PATIENTS/METHODS: A total of 514 clinical strains of T. rubrum and 240 T. mentagrophytes collected from four Czech clinical institutions were screened for terbinafine resistance. Molecular investigations included DNA sequencing, specifically the ITS rDNA region and SQLE gene, as well as antifungal susceptibility testing following EUCAST guidelines. RESULTS: While no resistance was observed in T. rubrum, 2.5% of T. mentagrophytes strains exhibited resistance, marked by the F397L mutation in SQLE. Notably, resistance surged from 1.2% in 2019 to 9.3% in 2020 but reverted to 0% in 2021. All resistant strains were identified as T. mentagrophytes var. indotineae. Resistant strains exhibited high MICs for terbinafine (≥4 mg L-1 ) but low MICs to the other seven antifungals tested except for fluconazole. CONCLUSIONS: This study highlights the emergence of terbinafine-resistant T. mentagrophytes strains in the Czech Republic, with the F397L mutation being pivotal. Due to the relatively low resistance level, the current guidelines for dermatomycosis treatment in the Czech Republic remain effective, but ongoing surveillance is essential for timely adaptations if resistance patterns change.

Enzootic Circulation, Massive Gull Mortality and Poultry Outbreaks during the 2022/2023 High-Pathogenicity Avian Influenza H5N1 Season in the Czech Republic.

In 2022/2023, Europe experienced its third consecutive season of high-pathogenicity avian influenza. During this period, the Czech Republic was again severely affected. For the first time, the number of culled birds approached one million, which was three times higher than in previous seasons. In parallel to the outbreaks in poultry, mass die-offs of gulls were also observed. In the present study, we performed whole-genome sequencing and phylogenetic analysis of 137 H5N1 strains collected in the Czech Republic in 2022/2023 (94.6% of all outbreaks or locations). The analysis revealed four distinct genotypes: AB, CH, BB and AF. Phylogenetic analysis suggested that the AF genotype persisted from the previous H5N1 season without reassortment. In addition, the genotype BB, which was detected mainly in gulls, showed a noticeable strain diversity at the local level. This virus was also responsible for a single outbreak in commercially bred turkeys. Finally, an interesting spatio-temporal cluster with three co-circulating H5N1 genotypes, AB, CH and AF, was identified with no evidence of intrasubtype reassortment. Highly sensitive molecular surveillance and the timely sharing of genomic sequences and associated metadata could greatly assist in tracking the spread and detecting molecular changes associated with the increased virulence of this potentially zoonotic pathogen.

Host-specific Cryptosporidium, Giardia and Enterocytozoon bieneusi in shelter dogs from central Europe.

Cryptosporidium spp., Giardia intestinalis and microsporidia are unicellular opportunistic pathogens that can cause gastrointestinal infections in both animals and humans. Since companion animals may serve as a source of infection, the aim of the present screening study was to analyse the prevalence of these intestinal protists in fecal samples collected from dogs living in 10 animal shelters in central Europe (101 dogs from Poland and 86 from the Czech Republic), combined with molecular subtyping of the detected organisms in order to assess their genetic diversity. Genus-specific polymerase chain reactions were performed to detect DNA of the tested species and to conduct molecular subtyping in collected samples, followed by statistical evaluation of the data obtained (using χ2 or Fisher's tests). The observed prevalence was 15.5, 10.2, 1 and 1% for G. intestinalis, Enterocytozoon bieneusi, Cryptosporidium spp. and Encephalitozoon cuniculi, respectively. Molecular evaluation has revealed the predominance of dog-specific genotypes (Cryptosporidium canis XXe1 subtype; G. intestinalis assemblages C and D; E. cuniculi genotype II; E. bieneusi genotypes D and PtEbIX), suggesting that shelter dogs do not pose a high risk of human transmission. Interestingly, the percentage distribution of the detected pathogens differed between both countries and individual shelters, suggesting that the risk of infection may be associated with conditions typical of a given location.

LDLR gene rearrangements in Czech FH patients likely arise from one mutational event.

BACKGROUND: Large deletions and duplications within the low-density lipoprotein receptor (LDLR) gene make up approximately 10% of LDLR pathogenic variants found in Czech patients with familial hypercholesterolemia. The goal of this study was to test the hypothesis that all probands with each rearrangement share identical breakpoints inherited from a common ancestor and to determine the role of Alu repetitive elements in the generation of these rearrangements. METHODS: The breakpoint sequence was determined by PCR amplification and Sanger sequencing. To confirm the breakpoint position, an NGS analysis was performed. Haplotype analysis of common LDLR variants was performed using PCR and Sanger sequencing. RESULTS: The breakpoints of 8 rearrangements within the LDLR gene were analysed, including the four most common LDLR rearrangements in the Czech population (number of probands ranging from 8 to 28), and four less common rearrangements (1-4 probands). Probands with a specific rearrangement shared identical breakpoint positions and haplotypes associated with the rearrangement, suggesting a shared origin from a common ancestor. All breakpoints except for one were located inside an Alu element. In 6 out of 8 breakpoints, there was high homology (≥ 70%) between the two Alu repeats in which the break occurred. CONCLUSIONS: The most common rearrangements of the LDLR gene in the Czech population likely arose from one mutational event. Alu elements likely played a role in the generation of the majority of rearrangements inside the LDLR gene.

"We Never Stop Singing": The Dynamics of the Mental and Physical Health of Czech Religious Pastors during the COVID-19 Pandemic.

This study explores the dynamics of coping strategies of Czech religious leaders during a peak of the COVID-19 pandemic. An interpretative phenomenological analysis reveals that mental health among pastors is closely linked to a need to maintain community and social contact, while physical health is related to limitations upon ritual elements. In all narratives, the lived experience of mental health in the form of prosocial behavior is significantly prioritized despite the possibility of spreading infection. The analysis also shows that maintaining the community is closely linked to risky behaviors, which positively affected group and individual well-being.

Direct mailing of HPV self-sampling kits to women aged 50-65 non-participating in cervical screening in the Czech Republic.

BACKGROUND: A population-based cervical cancer screening programme is implemented in the Czech Republic. However, participation is insufficient among women over 50 years. This study aimed to estimate the potential improvement in participation through directly mailed HPV self-sampling kits (HPVssk) compared with standard invitation letters in women aged 50-65 non-participating in screening. METHODS: The study recruited 1564 eligible women (no cervical cancer screening in the last 3 years or more, no previous treatment associated with cervical lesions or cervical cancer). Eight hundred women were mailed with an HPVssk (HPVssk group), and 764 women were sent a standard invitation letter (control group) inviting them to a routine screening (Pap test). The primary outcome was a comparison of the overall participation rate between study groups using a binominal regression model. RESULTS: The participation rate in the HPVssk group was 13.4% [95% confidence interval (CI) 11.2-15.9%; 7.4% of women returned the HPVssk and 6.0% attended gynaecological examination] and 5.0% (95% CI 3.6-6.8%) in the control group. Using the binominal regression model, the difference between the groups was estimated as 7.6% (95% CI 5.0-10.2%; P < 0.001). In the HPVssk group, 22% of women who returned HPVssk had a positive result and 70% of them underwent a follow-up examination. CONCLUSIONS: Compared with traditional invitation letters, the direct mailing of the HPVssk achieved a significantly higher participation rate, along with a notable HPV positivity rate among HPVssk responders. This approach offers a potentially viable method for engaging women who have not yet attended a cervical screening programme.

Cholesterol associated genetic risk score and acute coronary syndrome in Czech males.

BACKGROUND: Despite a general decline in mean levels across populations, LDL-cholesterol levels remain a major risk factor for acute coronary syndrome (ACS). The APOB, LDL-R, CILP, and SORT-1 genes have been shown to contain variants that have significant effects on plasma cholesterol levels. METHODS AND RESULTS: We examined polymorphisms within these genes in 1191 controls and 929 patients with ACS. Only rs646776 within SORT-1 was significantly associated with a risk of ACS (P < 0.05, AA vs. + G comparison; OR 1.21; 95% CI 1.01-1.45). With regard to genetic risk score (GRS), the presence of at least 7 alleles associated with elevated cholesterol levels was connected with increased risk (P < 0.01) of ACS (OR 1.26; 95% CI 1.06-1.52). Neither total mortality nor CVD mortality in ACS subjects (follow up-9.84 ± 3.82 years) was associated with the SNPs analysed or cholesterol-associated GRS. CONCLUSIONS: We conclude that, based on only a few potent SNPs known to affect plasma cholesterol, GRS has the potential to predict ACS risk, but not ACS associated mortality.

Severe decline in abundance of Cyathostoma lari, a parasite of the nasal and orbital sinuses of gulls, at their central European nesting grounds.

Cyathostoma lari is a parasite of the nasal and orbital sinuses of gulls and other hosts in Europe and Canada. Here, we provide an overview of previously published data on the prevalence and infection intensity of C. lari in gulls. Furthermore, based on our data, we analyze the spatiotemporal trends in the prevalence and intensity of infection by C. lari in Chroicocephalus ridibundus in Czechia (central Europe; data from 1964 to 2014) and compare them with those obtained from five species of gulls in Karelia (Northwest Russia; data from 2012-2020). Based on our preliminary observations, we hypothesized that C. lari is subject to a decline in certain regions, but this decline is not necessarily applicable throughout its distribution range. We found that the C. lari population crashed in specific parts of its distribution range. The reasons are unknown, but the observed population changes correspond with the diet switch of their core host in Czechia, C. ridibundus. We previously observed a diet switch in Czech C. ridibundus from earthworms (intermediate hosts of C. lari) to other types of food. This diet switch affected both young and adult birds. Nevertheless, it may not necessarily affect populations in other regions, where they depend less on earthworms collected from agrocenoses affected by agrochemicals and trampling. Correspondingly, we found that these changes were limited only to regions where the gulls feed (or fed) on arable fields. In Karelia, where arable fields are scarce, gulls likely continue to feed on earthworms and still display high infection rates by C. lari. Therefore, C. lari, a parasite of the nasal and orbital sinuses of gulls, nearly disappeared from their central European nesting grounds but is still present in better-preserved parts of its distribution range.

Microsporidia (Encephalitozoon cuniculi) in Patients with Degenerative Hip and Knee Disease, Czech Republic.

Total joint arthroplasty is a commonly used surgical procedure in orthopedics. Revision surgeries are required in >10% of patients mainly because of prosthetic joint infection caused by bacteria or aseptic implant loosening caused by chronic inflammation. Encephalitozoon cuniculi is a microsporidium, an obligate intracellular parasite, capable of exploiting migrating proinflammatory immune cells for dissemination within the host. We used molecular detection methods to evaluate the incidence of E. cuniculi among patients who had total hip or knee arthroplasty revision. Out of 49 patients, E. cuniculi genotypes I, II, or III were confirmed in joint samples from 3 men and 2 women who had implant loosening. Understanding the risks associated with the presence of microsporidia in periprosthetic joint infections is essential for proper management of arthroplasty. Furthermore, E. cuniculi should be considered a potential contributing cause of joint inflammation and arthrosis.

Palliative Care in the Ageing European Population: A Cross-Country Comparison.

With Europe's ageing population and rising demand for palliative care, it is crucial to examine the use of palliative care among older adults during their last years of life and understand the factors influencing their access and end-of-life circumstances. This study employed a cohort of SHARE participants aged 65 years or older who had passed away between Wave 6 (2015) and Wave 7 (2017). Information on death circumstances, palliative care utilization, and associated variables were analysed. The study revealed that nearly 13.0% of individuals across these countries died under palliative care, with Slovenia having the lowest rate (0.3%) and France the highest (30.4%). Palliative care utilization in the last 30 days before death was observed in over 24.0% of participants, with the Czech Republic having the lowest rate (5.0%) and Greece the highest (48.8%). A higher risk of using or dying in palliative care was significantly associated with cognitive impairment (low verbal fluency), physical inactivity, and good to excellent self-perceived health. This work highlights the urgent need for enhanced global access to palliative care and advocates for the cross-country comparison of effective practices within Europe, tailored to the unique healthcare needs of older adults.

Population mental health, help-seeking and associated barriers following the COVID-19 pandemic: Analysis of repeated nationally representative cross-sectional surveys in Czechia.

This study investigated the Czech adults' mental health following the COVID-19 pandemic and the potential influence of data collection methodology on prevalence estimates. Separately, it investigated changes in help-seeking and associated barriers. Data from representative surveys on Czech adults, conducted in November 2017 (n = 3,306), in May (n = 3,021) and November 2020 (n = 3,000), and in November and December 2022 (n = 7,311), were used. Current mental disorders were assessed by the Mini International Neuropsychiatric Interview, and the treatment gap was established in individuals scoring positively. In help-seeking individuals, encountering barriers was investigated. In 2017 and 2022, 20.02 % and 27.22 % of individuals had at least one mental disorder, respectively. The 2022 panel sampling and online and telephone interviewing estimates (34.29 % and 26.7 %) were substantially higher than those from household sampling and personal interviewing (19.9 %). Prevalence rates based on household sampling and personal interviewing were broadly consistent in 2017 and 2022. The treatment gap was around 80 % from 2017 to 2022. More than 50 % of individuals encountered structural barriers in help-seeking in 2022. This study showed that prevalence rates were still elevated in 2022, but suggests that data collection methodology influenced the estimates. Separately, the treatment gap remained consistently very high, and encountering structural barriers in help-seeking was common.

Countrywide analysis of heat- and cold-related mortality trends in the Czech Republic: growing inequalities under recent climate warming.

BACKGROUND: Only little is known about trends in temperature-mortality associations among the most vulnerable subgroups, especially in the areas of central and eastern Europe, which are considered major climatic hotspots in terms of heatwave exposure. Thus, we aimed to assess trends in temperature-related mortality in the Czech Republic by sex, age and cause of death, and to quantify the temporal evolution of possible inequalities. METHODS: We collected daily time series of all-cause (1987-2019) and cause-specific (1994-2019) mortality by sex and age category, and population-weighted daily mean 2-metre temperatures for each region of the Czech Republic. We applied a quasi-Poisson regression model to estimate the trends in region-specific temperature-mortality associations, with distributed lag non-linear models and multivariate random-effects meta-analysis to derive average associations across the country. We then calculated mortality attributable to non-optimal temperatures and implemented the indicator of sex- and age-dependent inequalities. RESULTS: We observed a similar risk of mortality due to cold temperatures for men and women. Conversely, for warm temperatures, a higher risk was observed for women. Results by age showed a clear pattern of increasing risk due to non-optimum temperatures with increasing age category. The relative risk (RR) related to cold was considerably attenuated in most of the studied subgroups during the study period, whereas an increase in the RR associated with heat was seen in the overall population, in women, in the age category 90+ years and with respect to respiratory causes. Moreover, underlying sex- and age-dependent inequalities experienced substantial growth. CONCLUSIONS: Our findings suggest ongoing adaptation to cold temperatures. Mal/adaptation to hot temperatures occurred unequally among population subgroups and resulted in growing inequalities between the sexes and among age categories.

Undermining support for COVID-19 public health policies: an analysis of the impact of subversive conspiracy narratives on Czech General Practitioners.

BACKGROUND: Limited knowledge exists regarding the impact of COVID-19 conspiracy theories on the professional practice of general practitioners (GPs). This study aimed to identify the basic characteristics of GPs who endorse COVID-19 conspiracy beliefs and compare their level of support for COVID-19 health policies with GPs who do not believe in conspiracies. METHODS: Between January and February 2021, a representative online survey was conducted among 1163 GPs in the Czech Republic. The sample was designed to be representative of members of The Association of GPs of the Czech Republic. RESULTS: The survey revealed that nearly 14% of the GPs surveyed believed in one or more COVID-19 conspiracies. The average age of GPs who endorsed conspiracies was 58, which was higher than the rest of the sample (average age of 50). GPs who believed in conspiracies were less likely to support COVID-19 public health policies and therapy recommendations, including vaccination. Logistic and linear regression analyses indicated that doctors who believed in conspiracies were 2.62 times less likely to have received a COVID-19 vaccine. Mediation analysis showed that approximately one-quarter (23.21%) of the total effect of trust in government information on support for public health policies was indirectly mediated by the endorsement of COVID-19 conspiracy beliefs. CONCLUSIONS: The study findings suggest a concerning association between belief in COVID-19 conspiracies and a reduced level of support for public health policies among GPs. These results underscore the importance of incorporating the 'conspiracy agenda' into medical authorities' more effective public health communication strategies.

Early vascular damage in retinal microcirculation in arterial hypertension: the Czech post-MONICA study.

Retinal microcirculation reflects retinal perfusion abnormalities and retinal arterial structural changes at relatively early stages of various cardiovascular diseases. Wall-to-lumen ratio (WLR) may represent the earliest step in hypertension-mediated organ damage.Our objective was to compare functional and structural parameters of retinal microcirculation in a randomly selected urban population sample, in hypertensive and normotensive individuals. DESIGN AND METHOD: A total of 398 randomly selected individuals from an urban population aged 25-65 years, residing in Pilsen, Czech Republic, were screened for major cardiovascular risk factors. Retinal microcirculation was assessed using scanning laser Doppler flowmetry, with data evaluable in 343 patients. Complete data were available for 342 individuals divided into four groups based on blood pressure and control status of hypertension: normotensive individuals ( n  = 213), treated controlled hypertensive individuals ( n  = 30), treated uncontrolled hypertensive individuals ( n  = 26), and newly detected/untreated hypertensive individuals ( n  = 73). RESULTS: There was a tendency to higher wall thickness in treated but uncontrolled hypertensive patients (compared to normotensive and treated controlled hypertensive individuals). WLR was significantly increased in treated but uncontrolled hypertensive patients as well as in individuals with newly detected thus untreated hypertension or in patients with known but untreated hypertension. There was no difference in WLR in treated, controlled hypertensive patients compared with normotensive individuals. CONCLUSION: Our results show that an increased WLR, reflecting early vascular damage, was found in newly detected individuals with hypertension and in untreated hypertensive patients, reflecting early hypertension-mediated vascular damage. Early initiation of hypertension treatment may be warranted.

Supplemental description of Gyrodactylus pseudorasborae (Gyrodactylidae) parasitic on topmouth gudgeon Pseudorasbora parva (Cyprinidae) in South China.

Based on morphology and ITS sequence data, we identify and supplementally describe Gyrodactylus pseudorasborae Ondracková, Seifertová & Tkachenko, 2023 on the fins of topmouth gudgeon (Pseudoraspora parva) from freshwaters of southern China. The highest similarity (99.57% and 99.47%) to G. pseudorasborae suggested they were the same species. Prevalence and mean intensity were 45% and 2.3, respectively. The gyrodactylid species morphologically resembled G. pseudorasborae recorded from the same host species P. parva in Czech Republic, Ukraine, and Central China. But there were slight morphological differences in the shape and size of the marginal hook. Comparisons of marginal hook sickles of various Gyrodactylus species suggested that G. pseudorasborae and G. parvae were members of the G. wageneri-group. A molecular phylogeny of G. pseudorasborae with related species is presented and discussed within the context of the mechanism of local evolution of these sister species.