Pre-existing Patterns Research Articles

Increasing disturbance frequency undermines coral reef recovery

AbstractClimate‐driven alterations to disturbance regimes are increasingly disrupting patterns of recovery in many biomes. Here, we examine the impact of disturbance and subsequent level of recovery in live hard coral cover on the Great Barrier Reef (GBR) across the last three decades. We demonstrate that a preexisting pattern of infrequent disturbances of limited spatial extent has changed to larger and more frequent disturbances, dominated by marine heatwaves and severe tropical cyclones. We detected an increase in the impact (measured as coral loss) across 265 individual disturbance impacts on 131 reefs in a 36‐year dataset (1985–2022). Additionally, the number of survey reefs impacted by disturbance has increased each decade from 6% in the 1980s to 44% in the 2010s, as has the frequency of mass coral bleaching across the GBR, which has increased between 19% and 28% per year, and cyclones (3%–5% per year), resulting in less time for recovery. Of the 265 disturbance impacts we recorded, complete recovery to the highest levels of coral cover recorded earlier in this study (the “historical benchmark”) occurred only 62 (23%) times. Of the 23% of disturbance impacts that resulted in complete recovery to historical benchmarks, 34/62 recovered to their benchmark in 2021 or 2022. Complete recovery was more likely when the historical benchmark was <25% live hard coral cover. The lack of recovery was attributed to recovery time windows becoming shorter due to increases in the frequency of cyclones and of thermal stress events that result in mass coral bleaching episodes. These results confirm that climate change is contributing to ecosystem‐wide changes in the ability of coral reefs to recover.

Pattern Matters in the Aposematic Colouration of Papilio polytes Butterflies.

Many toxic animals display bright colour patterns to warn predators about their toxicity. This sometimes leads other sympatric palatable organisms to evolve mimetic colour patterns to also evade predation. These mimics, however, are often imperfect, and it is unclear how much their colour patterns can vary away from the model before they become ineffective. In this study, we investigated how predation risk of the palatable Common Mormon butterfly (Papilio polytes) is affected by two alterations of its wing pattern that make it progressively more distinct from its model, the Common Rose (Pachliopta aristolochiae). We deployed butterfly paper models in the field, where all models displayed the same colours but had different patterns. In the first modification from the Wildtype pattern, we exchanged the position of the red and white colour patches but kept the overall pattern constant. In the second modification, we created an eyespot-like shape from the pre-existing pattern elements by moving their positions in the wing, altering the overall wing pattern. Both modifications increased attack risk from predators relative to Wildtype patterns, with the eyespot-like modification having the highest predation risk. Our results show that avian predators can distinguish between all three patterns tested, and that pattern is important in aposematic signals. Predators learn to avoid aposematic colours, not in isolation, but as part of specific patterns.

Phase Field Fracture Model for Assessing the Load Bearing Capacity of Fractured Glass

The use of glass as structural material has highlighted the need for more reliable numerical approaches to analyze its mechanical behavior, especially in the accidental eventuality of fracture. Modelling the behavior of fractured laminated glass, in fact, is fundamental to assess the Post-Fracture load-bearing capacity. However, this is a highly challenging task because of the many interplaying factors, such as the viscoelastic and thermal-dependent behavior of the interlayer, the presence of a highly complex and variable crack pattern and the interaction among fragments. The objective of the present work is the development and testing of a robust numerical model that can naturally introduce the generated crack pattern into virtual specimens and manage the interaction among many fragments. The phase field fracture model is herein explored, by assigning the damage variable to fit the pre-existing crack pattern. Then, the specimen is loaded letting the phase field managing the fragments interaction. The dependence of the stress tensor with the damage variable is herein defined through the Cleavage-Deviatoric model, since it prevents fully damaged regions from transmitting tensile and shear stresses yet keeping their ability to bear compressive forces. Indeed, this model can asymptotically reproduce unilateral and frictionless contact conditions between the existing crack lips. Preliminary case studies are discussed to check the potentiality of the proposed approach.

Impact of COVID-19 on referrals to outpatient palliative care for patients with advanced cancer in a safety-net health system.

e24071 Background: Medically underserved adults with cancer experience challenges with access to care and tend to present at later disease stage. Amidst the complex needs of safety-net patients, the value of early palliative care (PC) services can go unrecognized. Few studies have examined PC referral patterns in the outpatient setting among advanced cancer patients within a safety-net system, and none has studied how or whether referrals have evolved since the most acute stages of the COVID-19 pandemic. This study examined PC referrals for cancer patients seen as outpatients in the urban safety-net primary provider of cancer care for uninsured individuals in Dallas, TX, and assessed changes from before to after the acute pandemic phase. Methods: We used tumor registry records linked to outpatient PC referral data from the safety-net health system’s electronic health record from January 1, 2018 to July 31, 2023. The primary outcome was a binary indicator for receipt of PC referral among patients diagnosed with advanced-stage solid tumor cancer. Using a multivariate logistic regression model, we evaluated whether our independent variable – a binary indicator for pre-pandemic (January 1, 2018 to February 28, 2020) and post-pandemic (March 1, 2020 to July 31, 2023) time periods – was associated with PC referrals. We included age, sex, race/ethnicity, cancer type, preferred language, and insurance as covariates. Results: Among 1,590 eligible patients (mean age 58.1, range: 21-94), 44% were female and 75% were non-White. Diagnoses included lung (20%), gastrointestinal (17%), colorectal (14%), breast (9%), prostate (9%), head/neck (9%), pancreatic (8%), gynecologic (6%), and other (8%) cancers. Across both time periods, a total of 785 (49%) of patients received a PC referral. Whereas 53% of the 754 patients in the pre-pandemic cohort received a PC referral, 46% of the 836 in the post-pandemic cohort received a referral. In the adjusted regression model, pre-pandemic patients were 1.26 times more likely to have a PC referral than post-pandemic patients (95% CI, 1.02-1.56). Referrals varied by cancer type across both time periods – compared to breast cancer patients, gynecologic cancer patients had lower odds of PC referral (aOR, 0.19; 95% CI, 0.10-0.36) and pancreatic cancer patients had higher odds of PC referral (aOR, 2.93; 95% CI, 1.71-5.00). Conclusions: Our analysis showed that referrals declined during the COVID-19 pandemic and revealed differing underlying patterns of PC referral along disease groups. Understanding pre-existing referral patterns and lasting practice changes post-pandemic can support clinicians to integrate PC and improve cancer outcomes. Findings can be used to develop interventions, such as clinical triggers, to improve PC delivery for underserved cancer patients.

Impact of COVID-19 pandemic on breast cancer screening in a large midwestern United States academic medical center.

Access to breast screening mammogram services decreased during the COVID-19 pandemic. Our objectives were to estimate: 1) the COVID-19 affected period, 2) the proportion of pandemic-associated missed or delayed screening encounters, and 3) pandemic-associated patient attrition in screening encounters overall and by sociodemographic subgroup. We included screening mammogram encounter EPIC data from 1-1-2019 to 12-31-2022 for females ≥40 years old. We used Bayesian State Space models to describe weekly screening mammogram counts, modeling an interruption that phased in and out between 3-1-2020 and 9-1-2020. We used the posterior predictive distribution to model differences between a predicted, uninterrupted process and the observed screening mammogram counts. We estimated associations between race/ethnicity and age group and return screening mammogram encounters during the pandemic among those with 2019 encounters using logistic regression. Our analysis modeling weekly screening mammogram counts included 231,385 encounters (n = 127,621 women). Model-estimated screening mammograms dropped by >98% between 03-15-2020 and 05-24-2020 followed by a return to pre-pandemic levels or higher with similar results by race/ethnicity and age group. Among 79,257 women, non-Hispanic (NH) Asians, NH Blacks, and Hispanics had significantly (p < .05) lower odds of screening encounter returns during 2020-2022 vs. NH Whites with odds ratios (ORs) from 0.70 to 0.91. Among 79,983 women, those 60-69 had significantly higher odds of any return screening encounter during 2020-2022 (OR = 1.28), while those ≥80 and 40-49 had significantly lower odds (ORs 0.77, 0.45) than those 50-59 years old. A sensitivity analysis suggested a possible pre-existing pattern. These data suggest a short-term pandemic effect on screening mammograms of ~2 months with no evidence of disparities. However, we observed racial/ethnic disparities in screening mammogram returns during the pandemic that may be at least partially pre-existing. These results may inform future pandemic planning and continued efforts to eliminate mammogram screening disparities.

Towards a typology of virtual tourists: Efficacy of visual patterns and attentional cues

Virtual tourism is rapidly emerging in prominence in contemporary tourism research. Previous studies tend to consider the virtual tourism population as a homogeneous entity, resulting in unintended consequences. Despite the ocular-centric nature within virtual environments, existing eye tracking studies have rarely classified virtual tourists into benefit-based segments, discounting the critical role of pre-existing visual patterns and associated attentional cues. Subsequently, this research constructs a theoretically rigorous and evidence-informed typology of virtual tourists, based on attention patterns discerned from eye tracking trajectory and associated visual cues, triangulated with interview data. Building on the theory of bottom-up and top-down attentional processing, four discrete virtual tourist typologies emerged in terms of visual completeness and visual cognition: visual passives, curious scanners, focused observers, and comprehensive engagers. The visual and cognitive characteristics among the groups were collated, revealing significant differences articulated between each of the virtual tourist typologies. This research not only advances knowledge through a renewed emphasis on typology-driven theorising within the virtual tourism population, but also offers practical insights into implementing an innovative and effective segmentation approach. Future research should consider comparing the theoretical and empirical specifications of the virtual tourist typology.

The Wrong Side of the River: a Cantonese Emigrant Community in the Nineteenth-Century Mobility Transition

Abstract This focused study of one emigrant community in southern China explores linkages between internal and overseas migration during the nineteenth century, emphasizing both the diversity of lived experience and the contingent nature of categories that have informed the historiography of overseas Chinese migrants. Building on comparative studies that present an aggregate picture of changing migration patterns during the “mobility transition,” this microhistory shows how both preexisting and novel patterns of internal migration (urbanization, frontier migration, and military migration) shaped new strategies of overseas migration. For this particular emigrant community, new dynamics of migration in the mid-nineteenth century influenced the reputation of its emigrants, bringing about a transition from respectability to notoriety. Whereas earlier patterns of internal migration had linked this community to its neighbor on the opposite bank of the West River, new dynamics of migration in the nineteenth century bolstered the river’s role as a boundary. This community’s liminal place highlights the contingent nature of nineteenth-century tropes and current categories of overseas Chinese migrants.

From apprentice to president? Entertainment TV and US elections

This article studies the importance of entertainment TV for the selection of political leaders in the context of an important case study: Donald Trump's win in the 2016 presidential election and his previous role as host of the popular TV show “The Apprentice.” We find a positive correlation between TV ratings of The Apprentice and the county-level Republican vote share in 2016, but this correlation vanishes once we control for pre-existing voting and NBC viewership patterns. This null result is robust to different model specifications, measures of exposure to The Apprentice, and an extensive investigation of heterogeneous effects. Viewership of The Apprentice is also unrelated to Congressional election results, as well as support for Trump in survey data and the Republican primaries. These findings highlight the context-dependent importance of television for political leadership.

Correlation between Malocclusion and Mandibular Fractures: An Experimental Study Comparing Dynamic Finite Element Models and Clinical Case Studies.

Mandibular fractures are very common in maxillofacial trauma surgery. While previous studies have focused on possible risk factors related to post-operative complications, none have tried to identify pre-existing conditions that may increase the risk of mandibular fractures. We hypothesized, through clinical observation, that anatomical conditions involving poor dental contacts, such as malocclusions, may increase the risk of mandibular fractures. This work was subdivided into two parts. In the first part, Digital Imaging and Communications in Medicine (DICOM) data of four healthy patients characterized by different dentoskeletal occlusions (class I, class II, class III, and anterior open bite) have been used to develop four finite element models (FEMs) that accurately reproduce human bone structure. A vertical and lateral impact have been simulated at increasing speed on each model, analyzing the force distribution within the mandibular bone. Both vertical and lateral impact showed higher level of stress at the impact point and in the condylar area in models characterized by malocclusion. Specifically, the class III and the open bite models, at the same speed of impact, had higher values for a longer period, reaching critical stress levels that are correlated with mandibular fracture, while normal occlusion seems to be a protective condition. In the second part of this study, the engineering results were validated through the comparison with a sample of patients previously treated for mandibular fracture. Data from 223 mandibular fractures, due to low-energy injuries, were retrospectively collected to evaluate a possible correlation between pre-existing malocclusion and fracture patterns, considering grade of displacement, numbers of foci, and associated CFI score. Patients were classified, according to their occlusion, into Class I, Class II, Class III, and anterior open bite or poor occlusal contact (POC). Class I patients showed lower frequencies of fracture than class II, III, and open bite or POC patients. Class I was associated with displaced fractures in 16.1% of cases, class II in 47.1%, class III in 48.8% and open bite/POC in 65.2% of cases (p-value < 0.0001). In class I patients we observed a single non-displaced fracture in 51.6% of cases, compared to 12.9% of Class II, 19.5% of Class III and 22.7% of the open bite/POC group. Our analysis shows that class I appears to better dissipate forces applied on the mandible in low-energy injuries. A higher number of dental contacts showed a lower rate of multifocal and displaced fractures, mitigating the effect of direct forces onto the bone. The correlation between clinical data and virtual simulation on FEM models seems to point out that virtual simulation successfully predicts fracture patterns and risk of association with different type of occlusion. Better knowledge of biomechanics and force dissipation on the human body may lead to the development of more effective safety devices, and help select patients to plan medical, orthodontic/dental, and/or surgical intervention to prevent injuries.

Computer-assisted image analysis of preexisting histological patterns of the cephalic vein to predict wrist arteriovenous fistula non-maturation

BackgroundWe used computer-assisted image analysis to determine whether preexisting histological features of the cephalic vein influence the risk of non-maturation of wrist fistulas. MethodsThis study focused on patients aged 20–80 years who underwent their first wrist fistula creation. A total of 206 patients participated, and vein samples for Masson's trichrome staining were collected from 134 patients. From these, 94 patients provided a complete girth of the venous specimen for automatic image analysis. Maturation was assessed using ultrasound within 90 days after surgery. ResultsThe collagen to muscle ratio in the target vein, measured by computer-assisted imaging, was a strong predictor of non-maturation in wrist fistulas. Receiver operating characteristic analysis revealed an area under the curve of 0.864 (95% confidence interval of 0.782–0.946, p < 0.001). The optimal cut-off value for the ratio was 1.138, as determined by the Youden index maximum method, with a sensitivity of 89.0% and specificity of 71.4%. For easy application, we used a cutoff value of 1.0; the non-maturation rates for patients with ratios >1 and ≤ 1 were 51.7% (15 out of 29 patients) and 9.2% (6 out of 65 patients), respectively. Chi-square testing revealed significantly different non-maturation rates between the two groups (X2 (1, N = 94) = 20.9, p < 0.01). ConclusionComputer-assisted image interpretation can help to quantify the preexisting histological patterns of the cephalic vein, while the collagen-to-muscle ratio can predict non-maturation of wrist fistula development at an early stage.

DNA methylation-environment interactions in the human genome

Previously, we showed that a massively parallel reporter assay, mSTARR-seq, could be used to simultaneously test for both enhancer-like activity and DNA methylation-dependent enhancer activity for millions of loci in a single experiment (Lea et al., 2018). Here, we apply mSTARR-seq to query nearly the entire human genome, including almost all CpG sites profiled either on the commonly used Illumina Infinium MethylationEPIC array or via reduced representation bisulfite sequencing. We show that fragments containing these sites are enriched for regulatory capacity, and that methylation-dependent regulatory activity is in turn sensitive to the cellular environment. In particular, regulatory responses to interferon alpha (IFNA) stimulation are strongly attenuated by methyl marks, indicating widespread DNA methylation-environment interactions. In agreement, methylation-dependent responses to IFNA identified via mSTARR-seq predict methylation-dependent transcriptional responses to challenge with influenza virus in human macrophages. Our observations support the idea that pre-existing DNA methylation patterns can influence the response to subsequent environmental exposures—one of the tenets of biological embedding. However, we also find that, on average, sites previously associated with early life adversity are not more likely to functionally influence gene regulation than expected by chance.

DNA methylation-environment interactions in the human genome.

Previously, we showed that a massively parallel reporter assay, mSTARR-seq, could be used to simultaneously test for both enhancer-like activity and DNA methylation-dependent enhancer activity for millions of loci in a single experiment (Lea et al., 2018). Here, we apply mSTARR-seq to query nearly the entire human genome, including almost all CpG sites profiled either on the commonly used Illumina Infinium MethylationEPIC array or via reduced representation bisulfite sequencing. We show that fragments containing these sites are enriched for regulatory capacity, and that methylation-dependent regulatory activity is in turn sensitive to the cellular environment. In particular, regulatory responses to interferon alpha (IFNA) stimulation are strongly attenuated by methyl marks, indicating widespread DNA methylation-environment interactions. In agreement, methylation-dependent responses to IFNA identified via mSTARR-seq predict methylation-dependent transcriptional responses to challenge with influenza virus in human macrophages. Our observations support the idea that pre-existing DNA methylation patterns can influence the response to subsequent environmental exposures-one of the tenets of biological embedding. However, we also find that, on average, sites previously associated with early life adversity are not more likely to functionally influence gene regulation than expected by chance.

Pan-cancer analyses of the associations between 109 pre-existing conditions and cancer treatment patterns across 19 adult cancers

Comorbidities present considerable challenges to cancer treatment and care. However, little is known about the effect of comorbidity on cancer treatment decisions across a wide range of cancer types and treatment modalities. Harnessing a cohort of 280,543 patients spanning 19 site-specific cancers, we explored pan-cancer frequencies of 109 comorbidities. Multinomial logistic regression was used to analyse the relationship between comorbidities and cancer treatment types, while binomial logistic regression examined the association between comorbidities and chemotherapy drug types, adjusting for demographic and clinical factors. Patients with comorbidity exhibited lower odds of receiving chemotherapy and multimodality treatment. End-stage renal disease was significantly associated with a decreased odds of receiving chemotherapy and surgery. Patients with prostate cancer who have comorbid non-acute cystitis, obstructive and reflux uropathy, urolithiasis, or hypertension were less likely to receive chemotherapy. Among patients with breast cancer, dementia, left bundle branch block, peripheral arterial disease, epilepsy, Barrett’s oesophagus, ischaemic stroke, unstable angina and asthma were associated with lower odds of receiving multimodal chemotherapy, radiotherapy and surgery. Comorbidity is also consistently associated with the lower odds of receiving chemotherapy when comparing across 10 drug classes. Patients with comorbid dementia, intracerebral haemorrhage, subarachnoid haemorrhage, oesophageal varices, liver fibrosis sclerosis and cirrhosis and secondary pulmonary hypertension were less likely to receive antimetabolites. Comorbidity can influence the effectiveness and tolerability of cancer treatment and ultimately, prognosis. Multi-specialty collaborative care is essential for the management of comorbidity during cancer treatment, including prophylactic measures to manage toxicities.

MORAL AND ETHICAL COMPONENT OF SCIENCE IN TIMES OF WAR

MORAL AND ETHICAL COMPONENT OF SCIENCE IN TIMES OF WAR

Community Size and Electoral Preferences: Evidence From Post-Second World War Baden-Württemberg

Abstract We examine whether electoral preferences depend on a community's population size by studying post-Second World War Baden-Württemberg in Southwest Germany. Our identification strategy exploits the fact that the French administration zone prohibited German expellees from entering, contrary to the contiguous American zone. Population size positively predicts voting for the Social Democrats (the party advocating substantial government involvement in practically all domains) and negatively for the Christian Democrats (the small-government party advocating free-market policies). Results are neither driven by pre-existing voting patterns, religious compositions, and location- and time-specific unobservables, nor other measurable cultural, demographic, economic, or political characteristics. Alternative explanations pertaining to expellee voting behaviour or a backlash of natives against expellees appear unlikely – population size prevails as a predominant voting predictor.

Autocratic Power and Older Citizens: The Political Subjectification of Retirees in Belarus

This article contributes to research on everyday resistance as a means of citizens’ political subjectification in autocracies and advances the literature on the manipulation of news. Through analysis of state-controlled media and individual interviews, it traces how older people in Belarus engage in anti-authoritarian protests by relying on pre-existing patterns of interactions with the state. My analysis demonstrates that to promote its legitimacy, the paternalist regime cultivates dependence in older citizens and represents itself as the primary solution to problems associated with old-age vulnerability. In response to their systemic marginalisation in the job market, urban development and public health policies, older people claim their equal rights by resisting old-age vulnerability or performing it to challenge the system. The article argues that by practising low-key acts of insubordination, older Belarusians acquire the collective self-awareness and cultural competence that allowed them to engage in the 2020 protests as a distinct political subject.

Creativity in pivot audiovisual translation. Parasite subtitled and dubbed in Italian

ABSTRACT Creativity in pivot AVT is a burning issue, since the pivot text can be seen as imposing pre-existing patterns, which may limit the translator’s decision-making process and influence their creative output. To verify this, we examined the Italian subtitled and dubbed versions of the film Parasite (Bong Joon-ho, 2019), a well-known example of Korean audiovisual content transferred interlinguistically using English as a pivot language. The preliminary textual analysis of the data showed that both the Italian versions were also created using the pivot translation by Darcy Paquet. Being unable to retrieve the name of the Italian subtitler, we examined the Italian subtitles and found they are very close to the English pivot, often replicating some creative and controversial choices. For the Italian dubbing, we managed to interview the Italian dialogue writer (and dubbing director) and the translator. Their feedback on the translation process and the comparative analysis of the Korean source text, English subtitles and Italian dubbing demonstrated that the Italian dubbing team relied not only on the English subtitles but also on subtitles in other languages and the Korean script to create a text that often departs from the English pivot, and it is closer to the original.

Assessment and learning loss in England: never let a good crisis go to waste

ABSTRACT Disruption of the status quo caused by the pandemic in England provides a lens to view the priorities embedded in the qualifications system. The Government’s initial priority was to avert grade inflation, followed by a populist turn to teacher assessment after a widespread backlash. Subsequent Government arguments for the return to examinations as the fairest way to assess re-introduced policies which emphasised excellence agenda. Learning loss, a consequence of the pandemic, compounded pre-existing patterns of inequality. Inclusive policies to address this in the qualification system would require fundamentally different ways of thinking compared to, for example, the current adaptations that are made for young people with special educational needs because the modern inclusion agenda is broader. The excellence agenda assumes a competitive system in which educational resources must be rationed; that there will be winners and losers. We question this logic, arguing for principles that would underpin a more inclusive qualification system. Since 2015, pupils must stay in education or training until they are 18. Thus, at very least, rationing educational access before this is unwarranted. A modern approach would be more flexible, putting learners first and embrace diversity rather than standardisation as the main principle for fair assessment.

Do disasters exacerbate socioeconomic inequalities in health among older people?

Disasters can exacerbate socioeconomic health disparities because of differential exposure (e.g., socioeconomically disadvantaged groups are more likely to be exposed to disaster-related trauma) and differential vulnerability (disadvantaged groups are more likely to suffer health consequences of exposure to trauma). We sought to test whether health disparities among older adults widened in the area which was directly affected by the 2011 Great East Japan Earthquake & Tsunami compared to areas which largely escaped tsunami damage. We used data from a cohort of community-dwelling older adults who were directly affected by the 2011 disaster (the Iwanuma Study) and municipalities that were not directly affected (the JAGES parent cohort excluding Iwanuma city). The Iwanuma Study gathered pre-disaster information from participants in 2010 (seven months before the disaster) as well as post-disaster information in 2013, 2016 and 2019 (2.5, 5.5 and 8.5 years after the disaster). Our outcomes were depressive symptoms (GDS) and instrumental activities of daily living (IADL). We examined the pre-versus post-disaster trends in socioeconomic health disparities using the slope index and relative index of inequality. We then conducted a difference-in-difference analysis comparing the pre/post disaster change in health disparities in the “exposed” city (Iwanuma) compared to “control” cities. We found clear pre-disaster socioeconomic inequalities in both GDS and IADL in both the exposed and control cities. However, the magnitude of these inequalities did not change after the disaster on either the absolute or relative scales. The 2011 disaster in northeastern Japan did not exacerbate pre-existing patterns of health inequalities in the older population.

Robertsonian fusion triggers recombination suppression on sex chromosomes in Coleonyx geckos

The classical hypothesis proposes that the lack of recombination on sex chromosomes arises due to selection for linkage between a sex-determining locus and sexually antagonistic loci, primarily facilitated by inversions. However, cessation of recombination on sex chromosomes could be attributed also to neutral processes, connected with other chromosome rearrangements or can reflect sex-specific recombination patterns existing already before sex chromosome differentiation. Three Coleonyx gecko species share a complex X1X1X2X2/X1X2Y system of sex chromosomes evolved via a fusion of the Y chromosome with an autosome. We analyzed synaptonemal complexes and sequenced flow-sorted sex chromosomes to investigate the effect of chromosomal rearrangement on recombination and differentiation of these sex chromosomes. The gecko sex chromosomes evolved from syntenic regions that were also co-opted also for sex chromosomes in other reptiles. We showed that in male geckos, recombination is less prevalent in the proximal regions of chromosomes and is even further drastically reduced around the centromere of the neo-Y chromosome. We highlight that pre-existing recombination patterns and Robertsonian fusions can be responsible for the cessation of recombination on sex chromosomes and that such processes can be largely neutral.