Island area,body size and demographic history shape genomic diversity in Darwin's finches and related tanagers

Genomic diversity is the evolutionary foundation for adaptation to environmental change and thus is essential to consider in conservation planning. Island species are ideal for investigating the evolutionary drivers of genomic diversity, in part because of the potential for biological replicates. Here, we use genome data from 180 individuals spread among 27 island populations from 17 avian species to study the effects of island area, body size, demographic history and conservation status on contemporary genomic diversity. Our study expands earlier work on a small number of neutral loci to the entire genome and from a few species to many. We find significant positive correlation between island size and genomic diversity, a significant negative correlation between body size and genomic diversity, and that historical population declines significantly reduced contemporary genomic diversity. Our study shows that island size is the key factor in determining genomic diversity, indicating that habitat conservation is key to maintaining adaptive potential in the face of global environmental change. We found that threatened species generally had a significantly smaller values of Watterson's theta (θ_W = 4N_eμ) compared to nonthreatened species, suggesting that θ_W may be useful as a conservation indicator for at‐risk species. Overall, these findings (a) provide biological insights into how genomic diversity scales with ecological, morphological and demographic factors; and (b) illustrate how population genomic data can be leveraged to better inform conservation efforts.     

Explaining human uniqueness: genome interactions with environment, behaviour and culture

What makes us human? Specialists in each discipline respond through the lens of their own expertise. In fact, 'anthropogeny' (explaining the origin of humans) requires a transdisciplinary approach that eschews such barriers. Here we take a genomic and genetic perspective towards molecular variation, explore systems analysis of gene expression and discuss an organ-systems approach. Rejecting any 'genes versus environment' dichotomy, we then consider genome interactions with environment, behaviour and culture, finally speculating that aspects of human uniqueness arose because of a primate evolutionary trend towards increasing and irreversible dependence on learned behaviours and culture - perhaps relaxing allowable thresholds for large-scale genomic diversity.     

Evolutionary distinctiveness and historical decline in genetic diversity in the Seychelles Black Parrot Coracopsis nigra barklyi

Island endemic species are acutely vulnerable to extinction as a result of stochastic and human impacts. Conservation of unique island biodiversity is high priority, and an understanding of the evolutionary history of vulnerable island species is important to inform conservation management. The Seychelles Black Parrot Coracopsis nigra barklyi is an island endemic threatened with extinction. The total population of 520–900 individuals is restricted to the 38‐km² island of Praslin, and it is one of the last few remaining endemic island parrots that survive in the Indian Ocean. We combined mitochondrial and microsatellite DNA markers with morphological data to examine the evolutionary distinctiveness of C. n. barklyi within Coracopsis, and to compare levels of genetic diversity between historical and contemporary specimens. Phylogenetic analyses revealed C. n. barklyi as sister to the remaining three C. nigra subspecies, and discriminant function analysis suggested the Seychelles Black Parrot is the smallest of the four subspecies. Higher levels of genetic diversity were observed in historical specimens, whereas only one mtDNA haplotype was observed in the contemporary specimens, suggesting that C. n. barklyi has lost genetic diversity as a consequence of substantial recent population decline. This study provides a first insight into the evolutionary, genetic and morphological processes that have shaped C. n. barklyi and provides an important perspective on this parrot's current genetic status to guide its future conservation management. Further ecological studies are essential but we suggest that C. n. barklyi should be managed as an evolutionary significant unit to conserve its unique evolutionary pathway.     

Assessing the utility of conserving evolutionary history

It is often claimed that conserving evolutionary history is more efficient than species‐based approaches for capturing the attributes of biodiversity that benefit people. This claim underpins academic analyses and recommendations about the distribution and prioritization of species and areas for conservation, but evolutionary history is rarely considered in practical conservation activities. One impediment to implementation is that arguments related to the human‐centric benefits of evolutionary history are often vague and the underlying mechanisms poorly explored. Herein we identify the arguments linking the prioritization of evolutionary history with benefits to people, and for each we explicate the purported mechanism, and evaluate its theoretical and empirical support. We find that, even after 25 years of academic research, the strength of evidence linking evolutionary history to human benefits is still fragile. Most – but not all – arguments rely on the assumption that evolutionary history is a useful surrogate for phenotypic diversity. This surrogacy relationship in turn underlies additional arguments, particularly that, by capturing more phenotypic diversity, evolutionary history will preserve greater ecosystem functioning, capture more of the natural variety that humans prefer, and allow the maintenance of future benefits to humans. A surrogate relationship between evolutionary history and phenotypic diversity appears reasonable given theoretical and empirical results, but the strength of this relationship varies greatly. To the extent that evolutionary history captures unmeasured phenotypic diversity, maximizing the representation of evolutionary history should capture variation in species characteristics that are otherwise unknown, supporting some of the existing arguments. However, there is great variation in the strength and availability of evidence for benefits associated with protecting phenotypic diversity. There are many studies finding positive biodiversity–ecosystem functioning relationships, but little work exists on the maintenance of future benefits or the degree to which humans prefer sets of species with high phenotypic diversity or evolutionary history. Although several arguments link the protection of evolutionary history directly with the reduction of extinction rates, and with the production of relatively greater future biodiversity via increased adaptation or diversification, there are few direct tests. Several of these putative benefits have mismatches between the relevant spatial scales for conservation actions and the spatial scales at which benefits to humans are realized. It will be important for future work to fill in some of these gaps through direct tests of the arguments we define here.     

Evaluating the genome-wide impacts of species translocations: the greater prairie-chicken as a case study

A variety of conservation management strategies have been developed to address rapid, anthropogenically-driven biodiversity loss. The translocation of individuals from viable populations to those experiencing significant decline is one such strategy to increase genetic diversity and avoid extirpation, yet efficacy of this strategy has rarely been examined in detail utilizing genomic data. Here, we employ a conservation icon, the greater prairie-chicken (Tympanuchus cupido pinnatus), as a case study to demonstrate how genome-wide SNPs derived from RADseq offer the ability to assess translocation success with respect to the genomic aspects of genetic restoration, encompassing (1) the alleviation of inbreeding (2) the restoration of evolutionary potential, and (3) the maintenance of local variation. Genome-wide diversity estimates calculated from 356,778 SNPs demonstrate that translocations rescued the Illinois population from severe inbreeding and lack of genetic diversity, restoring variation to levels comparable to the three non-bottlenecked source populations. Delineation of genetic structure using non-linked and ubiquitously genotyped SNPs reveal distinct genetic variation among the source and recipient populations as well as high levels of admixture in the post-translocation population resulting from translocations. Estimated ancestry derived from private alleles uncover introgression of unique variation from each source population as well as the maintenance of substantial levels of variation unique to Illinois. Our findings demonstrate that genome-wide analysis of variation is a valuable management tool for measuring the genomic effects of translocations and, subsequently, gauging genetic restoration success.

     

Chromosomal domains of chimpanzee are diverged from human as revealed by in situ hybridization using human genomic probe

Utilization of repetitive DNA probes to assess the taxonomic affinity between related species has become the most powerful tool in evolutionary biology today. Consequently, tremendous strides have recently been made towards establishing the phylogenetic relationship of humans with chimpanzee. We employed human genomic proe (P5080 B.5) to identify the degree of divergence of chimpanzee genome from humans. A small protion of structurally distinct genomic areas in chimpanzee could be identified by fluorescencein situ hybridization (FISH) technique when compared to human DNA. The genomic divergence is confined mainly to the chromosomal ends in chimpanzee and may be an important phylogenetic characteristic in human evolution.     

Survival in the Tropics despite isolation,inbreeding and asexual reproduction: insights from the genome of the world’s southernmost poplar (Populus ilicifolia)

Species are becoming extinct at unprecedented rates as a consequence of human activity. Hence it is important to understand the evolutionary dynamics of species with already small population sizes. Populus ilicifolia is a vulnerable poplar species that is isolated from other poplar species and is uniquely adapted to the Tropics. It has a very limited size, reproduces partly clonally and is therefore an excellent case study for conservation genomics. We present here the first annotated draft genome of P. ilicifolia, characterize genome‐wide patterns of polymorphisms and compare those to other poplar species with larger natural ranges. P. ilicifolia experienced a more prolonged and severe decline of effective population size (N_e) and signs of genetic erosion than any other poplar species with which it was compared. At present, the species has the lowest genome‐wide genetic diversity, the highest abundance of long runs of homozygosity, high inbreeding levels as well as a high overall accumulation of deleterious variants. However, more effective purging of severely deleterious variants and adaptation to the Tropics may have contributed to its survival. Hence, in spite of its limited genetic variation, it is certainly worth pursuing the conservation efforts of this unique species.     

Conservation genetics of two critically endangered island dwarf carnivores

Genetic diversity is crucial for conservation biology and for understanding evolutionary processes. Oceanic islands harbor a unique biota and high endemism, with populations frequently facing detrimental genetic processes (e.g. drift, bottlenecks). Human activities like habitat transformation further increase extinction risk of insular biota. Mammals comprise the most endangered group among insular fauna. Our aim was to evaluate the genetic and evolutionary patterns of two critically endangered dwarf carnivores from Cozumel Island, the pygmy raccoon (Procyon pygmaeus) and the dwarf coati (Nasua nelsoni), at both historical and contemporary evolutionary scales. We also reviewed their genetic relationships with their mainland counterparts (P. lotor, N. narica), not intended to describe their phylogeny but to ascertain their endemism. Our mitochondrial results support that both Cozumel carnivores are divergent from continental populations, strengthening their endemic status. Both species showed moderate levels of nuclear genetic diversity that were, as expected for island populations, lower in comparison with their mainland congeneric species; they also exhibited significantly low population sizes. We documented historical and contemporary bottleneck signals for P. pygmaeus, whereas N. nelsoni may be suffering the initial stages of a bottleneck not yet fully manifested. The pygmy raccoon is structured into two isolated genetic clusters likely due to interactions with humans on the north of the island, where most potential for disease transmission and health problems exist. We also add evidence about the introduction of the mainland species into the island, risking genetic introgression and hybridization. We discuss specific conservation measures that should include our genetic information, directed to the long-term viability of these endemic carnivores.

     

Rhizobial communities in symbiosis with legumes: genetic diversity,competition and interactions with host plants

The term ‘Rhizobium-legume symbiosis’ refers to numerous plant-bacterial interrelationships. Typically, from an evolutionary perspective, these symbioses can be considered as species-to-species interactions, however, such plant-bacterial symbiosis may also be viewed as a low-scale environmental interplay between individual plants and the local microbial population. Rhizobium-legume interactions are therefore highly important in terms of microbial diversity and environmental adaptation thereby shaping the evolution of plant-bacterial symbiotic systems. Herein, the mechanisms underlying and modulating the diversity of rhizobial populations are presented. The roles of several factors impacting successful persistence of strains in rhizobial populations are discussed, shedding light on the complexity of rhizobial-legume interactions.     

Contribution of genetics and genomics to seagrass biology and conservation

Genetic diversity is one of three forms of biodiversity recognized by the IUCN as deserving conservation along with species and ecosystems. Seagrasses provide all three levels in one. This review addresses the latest advances in our understanding of seagrass population genetics and genomics within the wider context of ecology and conservation. Case studies are used from the most widely studied, northern hemisphere species Zostera marina, Z. noltii, Posidonia oceanica and Cymodocea nodosa.

We begin with an analysis of the factors that have shaped population structure across a range of spatial and temporal scales including basin-level phylogeography, landscape-scale connectivity studies, and finally, local-scale analyses at the meadow level—including the effects of diversity, clonality and mating system. Genetic diversity and clonal architecture of seagrass meadows differ within and among species at virtually all scales studied. Recent experimental studies that have manipulated seagrass genetic biodiversity indicate that genotypic diversity matters in an immediate ecological context, and enhances population growth, resistance and resilience to perturbation, with positive effects on abundance and diversity of the larger community. In terms of the longer term, evolutionary consequences of genetic/genotypic diversity in seagrass beds, our knowledge remains meagre. It is here that the new tools of ecogenomics will assist in unravelling the genetic basis for adaptation to both biotic and abiotic change. Gene expression studies will further assist in the assessment of physiological performance which may provide an early warning system under complex disturbance regimes that seagrasses are at or near their tolerance thresholds.

At the most fundamental level, ecological interactions of seagrasses with their environment depends on the genetic architecture and response diversity underlying critical traits. Hence, given the rapid progress in data acquisition and analysis, we predict an increasing role of genetic and genomic tools for seagrass ecology and conservation.     

Riverscape genomics of a threatened fish across a hydroclimatically heterogeneous river basin

Understanding how natural selection generates and maintains adaptive genetic diversity in heterogeneous environments is key to predicting the evolutionary response of populations to rapid environmental change. Detecting selection in complex spatial environments remains challenging, especially for threatened species where the effects of strong genetic drift may overwhelm signatures of selection. We carried out a basinwide riverscape genomic analysis in the threatened southern pygmy perch (Nannoperca australis), an ecological specialist with low dispersal potential. High‐resolution environmental data and 5162 high‐quality filtered SNPs were used to clarify spatial population structure and to assess footprints of selection associated with a steep hydroclimatic gradient and with human disturbance across the naturally and anthropogenically fragmented Murray–Darling Basin (Australia). Our approach included F_ST outlier tests to define neutral loci, and a combination of spatially explicit genotype–environment association analyses to identify candidate adaptive loci while controlling for the effects of landscape structure and shared population history. We found low levels of genetic diversity and strong neutral population structure consistent with expectations based on spatial stream hierarchy and life history. In contrast, variables related to precipitation and temperature appeared as the most important environmental surrogates for putatively adaptive genetic variation at both regional and local scales. Human disturbance also influenced the variation in candidate loci for adaptation, but only at a local scale. Our study contributes to understanding of adaptive evolution along naturally and anthropogenically fragmented ecosystems. It also offers a tangible example of the potential contributions of landscape genomics for informing in situ and ex situ conservation management of biodiversity.     

Correlated patterns of genetic diversity and differentiation across an avian family

Comparative studies of closely related taxa can provide insights into the evolutionary forces that shape genome evolution and the prevalence of convergent molecular evolution. We investigated patterns of genetic diversity and differentiation in stonechats (genus Saxicola), a widely distributed avian species complex with phenotypic variation in plumage, morphology and migratory behaviour, to ask whether similar genomic regions have become differentiated in independent, but closely related, taxa. We used whole‐genome pooled sequencing of 262 individuals from five taxa and found that levels of genetic diversity and divergence are strongly correlated among different stonechat taxa. We then asked whether these patterns remain correlated at deeper evolutionary scales and found that homologous genomic regions have become differentiated in stonechats and the closely related Ficedula flycatchers. Such correlation across a range of evolutionary divergence and among phylogenetically independent comparisons suggests that similar processes may be driving the differentiation of these independently evolving lineages, which in turn may be the result of intrinsic properties of particular genomic regions (e.g. areas of low recombination). Consequently, studies employing genome scans to search for areas important for reproductive isolation or adaptation should account for corresponding regions of differentiation, as these regions may not necessarily represent speciation islands or evidence of local adaptation.     

Phylogenetics support an ancient common origin of two scientific icons: Devils Hole and Devils Hole pupfish

The Devils Hole pupfish (Cyprinodon diabolis; DHP) is an icon of conservation biology. Isolated in a 50 m² pool (Devils Hole), DHP is one of the rarest vertebrate species known and an evolutionary anomaly, having survived in complete isolation for thousands of years. However, recent findings suggest DHP might be younger than commonly thought, potentially introduced to Devils Hole by humans in the past thousand years. As a result, the significance of DHP from an evolutionary and conservation perspective has been questioned. Here we present a high‐resolution genomic analysis of DHP and two closely related species, with the goal of thoroughly examining the temporal divergence of DHP. To this end, we inferred the evolutionary history of DHP from multiple random genomic subsets and evaluated four historical scenarios using the multispecies coalescent. Our results provide substantial information regarding the evolutionary history of DHP. Genomic patterns of secondary contact present strong evidence that DHP were isolated in Devils Hole prior to 20–10 ka and the model best supported by geological history and known mutation rates predicts DHP diverged around 60 ka, approximately the same time Devils Hole opened to the surface. We make the novel prediction that DHP colonized and have survived in Devils Hole since the cavern opened, and the two events (colonization and collapse of the cavern's roof) were caused by a common geologic event. Our results emphasize the power of evolutionary theory as a predictive framework and reaffirm DHP as an important evolutionary novelty, worthy of continued conservation and exploration.     

An essay on the necessity and feasibility of conservation genomics

The basic premise of conservation genetics is that small populations may be genetically threatened. The two steps leading to this premise are: (1) due to prominent influence of random genetic drift and inbreeding allelic and genotypic diversity in small populations is expected to be low, and (2) low allelic diversity and high homozygosity are expected to lead to immediate fitness decreases (inbreeding depression) and a compromised potential for evolutionary adaptation. Conservation genetic research has been strongly stimulated by the application of neutral molecular markers like microsatellites and AFLPs. In general these marker studies have provided evidence for step 1. It is less evident how these markers may provide evidence for step 2. In this essay we argue that, in order to get detailed insight in step 2, adopting a conservation genomic approach, in which conservation genetics will use approaches from ecological and evolutionary functional genomics (ecogenomics), is both necessary and feasible. Conservation genomics is necessary for studying functional genomic variation as function of drift and inbreeding, for studying the mechanisms that relate low genetic variation to low fitness, for integrating environmental and genetic approaches to conservation biology, and for developing modern, fast monitoring tools. The rapid technical and financial developments in genomics currently make conservation genomics feasible, and will improve feasibility in the very near future even further. We therefore argue that conservation genomics personifies part of the near future of conservation genetics.     

Combining molecular evolution and environmental genomics to unravel adaptive processes of MHC class IIB diversity in European minnows (Phoxinus phoxinus)

Host–pathogen interactions are a major evolutionary force promoting local adaptation. Genes of the major histocompatibility complex (MHC) represent unique candidates to investigate evolutionary processes driving local adaptation to parasite communities. The present study aimed at identifying the relative roles of neutral and adaptive processes driving the evolution of MHC class IIB (MHCIIB) genes in natural populations of European minnows (Phoxinus phoxinus). To this end, we isolated and genotyped exon 2 of two MHCIIB gene duplicates (DAB1 and DAB3) and 1′665 amplified fragment length polymorphism (AFLP) markers in nine populations, and characterized local bacterial communities by 16S rDNA barcoding using 454 amplicon sequencing. Both MHCIIB loci exhibited signs of historical balancing selection. Whereas genetic differentiation exceeded that of neutral markers at both loci, the populations' genetic diversities were positively correlated with local pathogen diversities only at DAB3. Overall, our results suggest pathogen‐mediated local adaptation in European minnows at both MHCIIB loci. While at DAB1 selection appears to favor different alleles among populations, this is only partially the case in DAB3, which appears to be locally adapted to pathogen communities in terms of genetic diversity. These results provide new insights into the importance of host–pathogen interactions in driving local adaptation in the European minnow, and highlight that the importance of adaptive processes driving MHCIIB gene evolution may differ among duplicates within species, presumably as a consequence of alternative selective regimes or different genomic context.     

Lack of genetic polymorphism among peregrine falcons Falco peregrinus of Fiji

We compared levels of genetic diversity and isolation among peregrine falcons Falco peregrinus from two South Pacific island complexes (Fiji and Vanuatu: F. p. nesiotes), relative to other island and mainland populations. Fragment data from 12 microsatellite loci and sequence information from the control region of the mitochondrial DNA indicated levels of genetic variation in the South Pacific populations were lower than other island and mainland populations. Indeed, diversity varied from extremely low (Vanuatu) to completely absent (Fiji). We find little support for a hypothesis that populations on Fiji or Vanuatu were colonized via Australia. The complete lack of polymorphism in peregrine falcons of Fiji is remarkable, and to our knowledge has not been observed in a natural avian population. This lack of polymorphism, and the inability to test for decrease in polymorphism using museum samples, precludes testing whether the lack of genetic diversity in the population on Fiji is due to a recent bottleneck, or sustained isolation over evolutionary time. Increased fertility in eggs of Fiji peregrines upon outbreeding with males from other areas is consistent with inbreeding depression within a population typified by heterozygote deficiency.     

Louse flies of Eleonora’s falcons that also feed on their prey are evolutionary dead‐end hosts for blood parasites

Host shifts are widespread among avian haemosporidians, although the success of transmission depends upon parasite‐host and parasite‐vector compatibility. Insular avifaunas are typically characterized by a low prevalence and diversity of haemosporidians, although the underlying ecological and evolutionary processes remain unclear. We investigated the parasite transmission network in an insular system formed by Eleonora's falcons (the avian host), louse flies that parasitize the falcons (the potential vector), and haemosporidians (the parasites). We found a great diversity of parasites in louse flies (16 Haemoproteus and 6 Plasmodium lineages) that did not match with lineages previously found infecting adult falcons (only one shared lineage). Because Eleonora's falcon feeds on migratory passerines hunted over the ocean, we sampled falcon kills in search of the origin of parasites found in louse flies. Surprisingly, louse flies shared 10 of the 18 different parasite lineages infecting falcon kills. Phylogenetic analyses revealed that all lineages found in louse flies (including five new lineages) corresponded to Haemoproteus and Plasmodium parasites infecting Passeriformes. We found molecular evidence of louse flies feeding on passerines hunted by falcons. The lack of infection in nestlings and the mismatch between the lineages isolated in adult falcons and louse flies suggest that despite louse flies’ contact with a diverse array of parasites, no successful transmission to Eleonora's falcon occurs. This could be due to the falcons’ resistance to infection, the inability of parasites to develop in these phylogenetically distant species, or the inability of haemosporidian lineages to complete their development in louse flies.     

Mapping the evolutionary twilight zone: molecular markers, populations and geography

Since evolutionary processes, such as dispersal, adaptation and drift, occur in a geographical context, at multiple hierarchical levels, biogeography provides a central and important unifying framework for understanding the patterns of distribution of life on Earth. However, the advent of molecular markers has allowed a clearer evaluation of the relationships between microevolutionary processes and patterns of genetic divergence among populations in geographical space, triggering the rapid development of many research programmes. Here we provide an overview of the interpretation of patterns of genetic diversity in geographical and ecological space, using both implicit and explicit spatial approaches. We discuss the actual or potential interaction of phylogeography, molecular ecology, ecological genetics, geographical genetics, landscape genetics and conservation genetics with biogeography, identifying their respective roles and their ability to deal with ecological and evolutionary processes at different levels of the biological hierarchy. We also discuss how each of these research programmes can improve strategies for biodiversity conservation. A unification of these research programmes is needed to better achieve their goals, and to do this it is important to develop cross‐disciplinary communication and collaborations among geneticists, ecologists, biogeographers and spatial statisticians.     

Lessons from the deep: mechanisms behind diversification of eukaryotic protein complexes

Genetic variation is the major mechanism behind adaptation and evolutionary change. As most proteins operate through interactions with other proteins, changes in protein complex composition and subunit sequence provide potentially new functions. Comparative genomics can reveal expansions, losses and sequence divergence within protein-coding genes, but in silico analysis cannot detect subunit substitutions or replacements of entire protein complexes. Insights into these fundamental evolutionary processes require broad and extensive comparative analyses, from both in silico and experimental evidence. Here, we combine data from both approaches and consider the gamut of possible protein complex compositional changes that arise during evolution, citing examples of complete conservation to partial and total replacement by functional analogues. We focus in part on complexes in trypanosomes as they represent one of the better studied non-animal/non-fungal lineages, but extend insights across the eukaryotes by extensive comparative genomic analysis. We argue that gene loss plays an important role in diversification of protein complexes and hence enhancement of eukaryotic diversity.     

Colonizing the world in spite of reduced MHC variation

The major histocompatibility complex (MHC), which harbours the most polymorphic vertebrate genes, plays a critical role in the host-pathogen coevolutionary arms race. However, the extent to which MHC diversity determines disease susceptibility and long-term persistence of populations is currently under debate, as recent studies have demonstrated that low MHC variability does not necessarily hamper population viability. However, these studies typically assayed small and decimated populations in species with restricted distribution, thereby making inferences about the evolutionary potential of these populations difficult. Here, we show that MHC impoverishment has not constrained the ecological radiation and flourishing of falcons (Aves: Falconidae) worldwide. We found two remarkably different patterns of MHC variation within the genus Falco. Whereas MHC variation in kestrels (the basal group within the genus) is very high, falcons exhibit ancestrally low intra- and interspecific MHC variability. This pattern is not due to the inadvertent survey of paralogous genes or pseudogenes. Further, patterns of variation in mitochondrial or other nuclear genes do not indicate a generalized low level of genome-wide variability among falcons. Although a relative contribution of genetic drift cannot be completely ruled out, we propose the falcons went through an evolutionary transition, driven and maintained by natural selection, from primarily highly variable towards low polymorphic and slow-evolving MHC genes with a very specific immune function. This study highlights that the importance of MHC diversity cannot be generalized among vertebrates, and hints at the evolution of compensatory immune mechanisms in falcons to cope with emerging and continuously evolving pathogens.