Morphology and morphometry of two hybridizing buntings at their hybrid zone in northern Iran reveal intermediate and transgressive morphotypes

The closely related Black-headed Bunting(Emberiza melanocephala,a western Palearctic lineage)and Red-headed Bunting(Emberiza bruniceps,an eastern Palearctic lineage)hybridize and replace each other south of the Caspian Sea.The parental species have distinct phenotypes and therefore morphology is useful for assessing hybridization in the contact zone.In the years of 1940 and 1977,quite a few hybrids were collected and studied morphologically.Since then,the hybrid zone appears to have expanded westwards,but there has been a time gap in the collection of morphological data.Here we reanalyze bunting specimens morphologically and compare the historical data with recent data.Morphometric and phenotypic traits from three time periods(1940,1977 and recent)were studied to assess phenotypic variation of hybrids,pattern of hybridization,and transgressive traits in the hybrid zone.Our results show that most of the birds in the hybrid zone exhibit intermediate phenotypes(both colors and morphometric characters),ranging from the pure phenotype of either of the parental species.However,hybridization has also produced novel phenotypes not seen in any of the parents.Using a canonical discriminant function analysis,the morphometric characters separated each parental species and the hybrids quite well.Our results showed morphometric intermediacy of hybrids in accordance with phenotypes.We observe a time trend in which recent hybrids are more similar to Red-headed Buntings phenotypically compared to historical samples.This pattern is likely a signature of a westward expansion of the Red-headed Bunting into the breeding range of the Black-headed Bunting.

Hybridization and genome evolution II： Mechanisms of species divergence and their effects on evolution in hybrids

Recent genomic studies have highlighted the importance of hybridization and gene exchange in evolution. We ask what factors cause variation in the impact of hybridization, through adaptation in hybrids and the likelihood of hybrid speciation. During speciation, traits that diverge due to both divergent and stabilizing selection can contribute to the buildup of reproductive isolation. Divergent directional selection in parent taxa should lead to intermediate phenotypes in hybrids, whereas stabilizing se- lection can also produce extreme, transgressive phenotypes when hybridization occurs. By examining existing theory and em- pirical data, we discuss how these effects, combined with differences between modes of divergence in the chromosomal distribu- tion of incompatibilities, affect adaptation and speciation in hybrid populations. The result is a clear and testable set of predic- tions that can be used to examine hybrid adaptation and speciation. Stabilizing selection in parents increases transgression in hy- brids, increasing the possibility for novel adaptation. Divergent directional selection causes intermediate hybrid phenotypes and increases their ability to evolve along the direction of parental differentiation. Stabilizing selection biases incompatibilities to- wards autosomes, leading to reduced sexual correlations in trait values and reduced pleiotropy in hybrids, and hence increased freedom in the direction of evolution. Directional selection causes a bias towards sex-linked incompatibilities, with the opposite consequences. Divergence by directional selection leads to greater dominance effects than stabilizing selection, with major but variable impacts on hybrid evolution [Current Zoology 59 （5）： 675-685, 2013].

Relationship between increase rate of human plague in China and global climate index as revealed by cross-spectral and cross-wavelet analyses

Plague has caused the death of hundreds of millions of people throughout the human history.Today this disease is again re-emerging and hence is again becoming an increasing threat to human health in several parts of the world.However,impacts of global climate variation(e.g.El Nino and Southern Oscillation[ENSO])and global warming on plagues are largely unknown.Using cross-spectral analysis and cross-wavelet analysis,we have analyzed the relationship between increase rate of human plague in China during 1871–2003 and the following climate factors(as measured by the Southern Oscillation Index[SOI],Sea Surface Temperature of east Pacific equator[SST]and air Temperature of the Northern Hemisphere[NHT]).We found in the frequency domain that increase rate of human plague was closely associated with SOI and SST.Cross-spectral analysis reveals that significant coherencies between increase rate of human plague and ENSO were found over short periods(2–3 years),medium periods(6–7 years)and long periods(11–12 years,30–40 years).Cross-wavelet analysis reveals that increase rate of human plague oscillates in phase with SOI,but in anti-phase with SST over periods of 2–4 years and approximately 8 years(6–10 years).These results indicate that ENSO-driven climate variation may be important for occurrences of human plague in China.However,there is a need for a further analysis of the underlying mechanism between human plague in China and ENSO.

Hybridization and genome evolution I： The role of contingency during hybrid speciation

Homoploid hybrid speciation （HHS） involves the recombination of two differentiated genomes into a novel, func- tional one without a change in chromosome number. Theoretically, there are numerous ways for two parental genomes to recom- bine. Hence, chance may play a large role in the formation of a hybrid species. If these genome combinations can evolve rapidly following hybridization and sympatric situations are numerous, recurrent homoploid hybrid speciation is a possibility. We argue that three different, but not mutually exclusive, types of contingencies could influence this process. First, many of these ＂hopeful monsters＂ of recombinant parent genotypes would likely have low fitness. Only specific combinations of parental genomic con- tributions may produce viable, intra-fertile hybrid species able to accommodate potential constraints arising from intragenomic conflict. Second, ecological conditions （competition, geography of the contact zones or the initial frequency of both parent spe- cies） might favor different outcomes ranging from sympatric coexistence to the formation of hybrid swarms and ultimately hybrid speciation. Finally, history may also play an important role in promoting or constraining recurrent HHS if multiple hybridization events occur sequentially and parental divergence or isolation differs along this continuum. We discuss under which conditions HHS may occur multiple times in parallel and to what extent recombination and selection may fuse the parent genomes in the same or different ways. We conclude by examining different approaches that might help to solve this intriguing evolutionary puz- zle [Current Zoology 59 （5）： 667-674, 2013].

Role of conspecifics and personal experience on behavioral avoidance of contaminated flowers by bumblebees

Pollinators use multiple cues whilst foraging in eluding direct cues from flowers and in direct cues from other pollinators. The use of indirect social cues is common in social in sects, such as honeybees and bumblebees, where a social environment facilitates the ability to use such cues. Bumblebees use cues to forage on flowers according to previous foraging experiences. Flowers are an essential food source for pollinators but also pose a high risk of parasite infection through the shared use of flowers leading to parasite spillover. Nevertheless, bumblebees have evolved behavioral defense mechanisms to limit parasite infection by avoiding contaminated flowers. Mechanisms underlying the avoidance of contaminated flowers by bumblebees are poorly understood. Bumblebees were recorded having the choice to forage on non-contaminated flowers and flowers contaminated by a trypan osome gut parasite, Crithidia bombi. The use of different treatments with presence or absence of con specifics on both con taminated and non-contami nated flowers allowed to investigate the role of social visual cues on their pathogen avoidance behavior. Bumblebees are expected to use social visual cues to avoid contaminated flowers. Our study reveals that the presence of a con specific on flowers either con taminated or not does not help bumblebee foragers avoiding contaminated flowers. Nevertheless, bumblebees whereas gaining experie nee tend to avoid their con specific when placed on contami nated flower and copy it whe n on the non-contami nated flower. Our experime nt suggests a detrime ntal impact of floral see nt on disease avoidanee behavior.

Identifying the spatiotemporal clusters of plague occurrences in China during the Third P Identifying the spatiotemporal clusters of plague occurrences in China during the Third Pandemic andemic

Plague,a devastating infectious disease caused by Yersinia pestis,has killed millions of people in the past and is still active in the natural foci of the world today.Understanding the spatiotemporal patterns of plague outbreaks in history is critically important,as it may help to facilitate prevention and control of potential future outbreaks.In this study,we explored spatiotemporal clusters of human plague occurrences in China using a machine-learning clustering method and reconstructed the potential transmission pattern during the Third Pandemic(1772-1964).We succeeded in identifying 6 clusters in the space domain(2D)and 13 clusters in the spatiotemporal domain(3D).Our results suggest that there were several temporal outbreaks and transmissions of plague in different spatial clusters.Together with the spatiotemporal nearest neighbor approach(ST-NNA),this method could allow us to have a clearer look at the spatiotemporal patterns of plague.

Ecometrics:The traits that bind the past and present together

We outline here an approach for understanding the biology of climate change,one that integrates data at multiple spatial and temporal scales.Taxon-free trait analysis,or“ecometrics,”is based on the idea that the distribution in a community of ecomorphological traits such as tooth structure,limb proportions,body mass,leaf shape,incubation temperature,claw shape,any aspect of anatomy or physiology can be measured across some subset of the organisms in a community.Regardless of temporal or spatial scale,traits are the means by which organisms interact with their environment,biotic and abiotic.Ecometrics measures these interactions by focusing on traits which are easily measurable,whose structure is closely related to their function,and whose function interacts directly with local environment.Ecometric trait distributions are thus a comparatively universal metric for exploring systems dynamics at all scales.The main challenge now is to move beyond investigating how future climate change will affect the distribution of organisms and how it will impact ecosystem services and to shift the perspective to ask how biotic systems interact with changing climate in general,and how climate change affects the interactions within and between the components of the whole biotic-physical system.We believe that it is possible to provide believable,quantitative answers to these questions.Because of this we have initiated an IUBS program iCCB(integrative Climate Change Biology).

Evaluating the effectiveness of control measures in multiple regions during the early phase of the COVID-19 pandemic in 2020

The number of COVID-19 confirmed cases rapidly grew since the SARS-CoV-2 virus was identified in late 2019.Due to the high transmissibility of this virus,more countries are experiencing the repeated waves of the COVID-19 pandemic.However,with limited manufacturing and distribution of vaccines,control measures might still be the most critical measures to contain outbreaks worldwide.Therefore,evaluating the effectiveness of various control measures is necessary to inform policymakers and improve future preparedness.In addition,there is an ongoing need to enhance our understanding of the epidemiological parameters and the transmission patterns for a better response to the COVID-19 pandemic.This review focuses on how various models were applied to guide the COVID-19 response by estimating key epidemiologic parameters and evaluating the effectiveness of control measures.We also discuss the insights obtained from the prediction of COVID-19 trajectories under different control measures scenarios.

Plague reservoir species throughout the world

Plague has been known since ancient times as a re-emerging infectious disease,causing considerable socioeconomic burden in regional hotspots.To better understand the epidemiological cycle of the causative agent of the plague,its potential occurrence,and possible future dispersion,one must carefully consider the taxonomy,distribution,and ecological requirements of reservoir-species in relation either to natural or human-driven changes(e.g.climate change or urbanization).In recent years,the depth of knowledge on species taxonomy and species composition in different landscapes has undergone a dramatic expansion,driven by modern taxonomic methods such as synthetic surveys that take into consideration morphology,genetics,and the ecological setting of captured animals to establish their species identities.Here,we consider the recent taxonomic changes of the rodent species in known plague reservoirs and detail their distribution across the world,with a particular focus on those rodents considered to be keystone host species.A complete checklist of all known plague-infectable vertebrates living in plague foci is provided as a Supporting Information table.

Analyzing short time series data from periodically fluctuating rodent populations by thresholdmodels: A nearest block bootstrap approach

The study of the rodent fluctuations of the North was initiated in its modern form with Elton's pioneering work.Many scientific studies have been designed to collect yearly rodent abundance data,but the resulting time series are generally subject to at least two "problems":being short and non-linear.We explore the use of the continuous threshold autoregressive(TAR) models for analyzing such data.In the simplest case,the continuous TAR models are additive autoregressive models,being piecewise linear in one lag,and linear in all other lags.The location of the slope change is called the threshold parameter.The continuous TAR models for rodent abundance data can be derived from a general prey-predator model under some simplifying assumptions.The lag in which the threshold is located sheds important insights on the structure of the prey-predator system.We propose to assess the uncertainty on the location of the threshold via a new bootstrap called the nearest block bootstrap(NBB) which combines the methods of moving block bootstrap and the nearest neighbor bootstrap.The NBB assumes an underlying finite-order time-homogeneous Markov process.Essentially,the NBB bootstraps blocks of random block sizes,with each block being drawn from a non-parametric estimate of the future distribution given the realized past bootstrap series.We illustrate the methods by simulations and on a particular rodent abundance time series from Kilpisjrvi,Northern Finland.

The Biological Consequences of Global Change

ChangeClimate is currently changing.These changes will havea variety of effects on biological systems,at various lev-els spanning from the physiological to the ecosystem level.Zoologists,among others,need to address the questionof how climate changes(and variation)affect biologicalprocess at these different levels of organization,and theyneed to do so in an integrated manner.With this view inmind,Integrative Zoology is pleased to present this spe-cial issue on“the biological consequences of globalchange.”This special issue is linked to a larger initiativeof the International Society of Zoological Sciences,namely,its flagship research program with the same title:the“Bio-logical Consequences of Global Change”(BCGC).Thisspecial issue is the first in a series of such issues:duringthe period 2010 to 2012 Integrative Zoology plan to pub-lish one such special issue per year.

Changing climate patterns risk the spread of Varroa destructor infestation of African honey bees in Tanzania

Background:Climate change creates opportune conditions that favour the spread of pests and diseases outside their known active range.Modelling climate change scenarios is oftentimes useful tool to assess the climate analogues to unveil the potential risk of spreading suitability conditions for pests and diseases and hence allows development of appropriate responses to address the impending challenge.In the current study,we modelled the impact of climate change on the distribution of Varroa destructor,a parasitic mite that attacks all life forms of honey bees and remains a significant threat to their survival and productivity of bee products in Tanzania and elsewhere.Methods:The data about the presence of V.destructor were collected in eight regions of Tanzania selected in consideration of several factors including potentials for beekeeping activities,elevation(highlands vs.lowlands)and differences in climatic conditions.A total of 19 bioclimatic datasets covering the entire country were used for developing climate scenarios of mid-century 2055 and late-century 2085 for both rcp4.5 and rcp8.5.We thereafter modelled the current and future risk distribution of V.destructor using MaxEnt.Results:The results indicated a model performance of AUC=0.85,with mean diurnal range in temperature(Bio2,43.9%),mean temperature(Bio1,20.6%)and mean annual rainfall(Bio12,11.7%)as the important variables.Future risk projections indicated mixed responses of the potential risk of spreads of V.destructor,exhibiting both decrease and increases in the mid-century 2055 and late-century 2085 on different sites.Overall,there is a general decline of highly suitable areas of V.destructor in mid-and late-century across all scenarios(rcp4.5 and rcp8.5).The moderately suitable areas indicated a mixed response in mid-century with decline(under rcp4.5)and increase(under rcp8.5)and consistent increase in late century.The marginally suitable areas show a decline in mid-century and increase in late-century.Our results suggest that the climate change will continue to significantly affect the distribution and risks spread of V.destructor in Tanzania.The suitability range of V.destructor will shift where highly suitable areas will be diminishing to the advantage of the honey bees’populations,but increase of moderately suitable sites indicates an expansion to new areas.The late century projections show the increased risks due to surge in the moderate and marginal suitability which means expansion in the areas where V.destructor will operate Conclusion:The current and predicted areas of habitat suitability for V.destructor’s host provides information useful for beekeeping stakeholders in Tanzania to consider the impending risks and allow adequate interventions to address challenges facing honey bees and the beekeeping industry.We recommend further studies on understanding the severity of V.destructor in health and stability of the honey bees in Tanzania.This will provide a better picture on how the country will need to monitor and reduce the risks associated with the increase of V.destructor activities as triggered by climate change.The loss of honey bees’colonies and its subsequent impact in bees’products production and pollination effect have both ecological and economic implications that need to have prioritization by the stakeholders in the country to address the challenge of spreading V.destructor.

Reflections from the president of the International Society of Zoological Sciences:the zoology of zoonotic infectious diseases

The past 2 years we now have behind us have demonstrated the importance of understanding the dynamics of zoonotic diseases in the wild and how the disease agents spill over to the human population.At the end of 2021,Integrative Zoology published 2 special subsections on this topic,one of which focuses on plague—a zoonotic infectious disease which through history has ravaged the world.Plague,caused by the bacterium Yersinia pestis,continues to cause deaths among people.I am quite confident that we will not get rid of wildlife plague,but human plague epidemics might be history in the not too distant future(Baril et al.2019;Vallès et al.2020).

Contrasting phenology responses to climate warming across the northern extra-tropics

Climate warming has substantially advanced the timing of spring leaf-out of woody species at middle and high latitudes,albeit with large differences.Insights in the spatial variation of this climate warming response may therefore help to constrain future trends in leaf-out and its impact on energy,water and carbon balances at global scales.In this study,we used in situ phenology observations of 38 species from 2067 study sites,distributed across the northern hemisphere in China,Europe and the United States,to investigate the latitudinal patterns of spring leaf-out and its sensitivity(S T,advance of leaf-out dates per degree of warming)and correlation(R_(T),partial correlation coefficient)to temperature during the period 1980-2016.Across all species and sites,we found that S_(T) decreased significantly by 0.15±0.02 d℃^(-1)°N^(-1),and R_(T) increased by 0.02±0.001°N^(-1)(both at P<0.001).The latitudinal patterns in R_(T) and S_(T) were explained by the differences in requirements of chilling and thermal forcing that evolved to maximize tree fitness under local climate,particularly climate predictability and summed precipitation during the pre-leaf-out season.Our results thus showed complicated spatial differences in leaf-out responses to ongoing climate warming and indicated that spatial differences in the interactions among environmental cues need to be embedded into large-scale phenology models to improve the simulation accuracy.