Fitness Of Species Research Articles

Analysis of Selected IT Tools for Environmental Product Assessment

This article discusses the subject of the environmental assessment of products based on specific methods (LCA, ReCiPe, and SM2013) and tools (GaBi, SimaPro, and Sustainable Minds). The aim of this work was to analyze selected IT tools for supporting such an assessment. Assumptions and criteria were adopted, based on which specific IT tools were selected for a comparative analysis. Then, an environmental assessment of reference products was carried out using three different IT tools. The structure of the products was prepared in such a way that the parts and subassemblies met two basic requirements. First, they were made of construction materials that are generally available and used in industry. The second requirement was that the technologies for manufacturing these parts included as many frequently used technological processes as possible. This allowed for a comparison of the results of estimated environmental assessments generated by selected IT tools. As a result, the strengths and weaknesses of each of the IT tools were identified.

Drivers of geophagy of large-bodied amazonian herbivorous and frugivorous mammals

Mineral licks, critical for the survival of many large-bodied mammals in the Amazon, serve as keystone resources that influence the behavior and ecological dynamics of these species. This study presents the most comprehensive analysis to date on the drivers of geophagy—the consumption of soil by animals—at mineral licks in the Peruvian Amazon. Using a combination of camera traps and soil analyses from 52 mineral licks, we examined the visitation patterns of six large-bodied mammals: the black agouti (Dasyprocta fuliginosa), paca (Cuniculus paca), collared peccary (Pecari tajacu), Brazilian porcupine (Coendou prehensilis), lowland tapir (Tapirus terrestris), and red howler monkey (Alouatta seniculus). Our results reveal that mineral licks provide essential nutrients, particularly sodium (Na), which may be deficient in the diets of frugivorous species such as agouti, paca, and red howler monkey, supporting the mineral supplementation hypothesis. Conversely, the toxin adsorption hypothesis, which posits that animals consume soil to mitigate dietary toxins, was most strongly supported for the herbivorous Brazilian porcupine. The omnivorous collared peccary and the mixed-diet tapir exhibited complex interactions between soil characteristics, suggesting that both mineral supplementation and toxin adsorption play roles in their geophagy. This study highlights the importance of mineral licks for the conservation of Amazonian mammals, emphasizing their role in supporting biodiversity by providing critical nutritional resources that enhance species fitness and ecological resilience. Our findings underscore the need for the protection of these sites, which are integral not only to the survival of individual species but also to the health of the broader Amazonian ecosystem.

Polymicrobial interactions influence Mycobacterium abscessus co-existence and biofilm forming capabilities.

The lungs of patients with cystic fibrosis (CF) are vulnerable to persistent polymicrobial colonization by bacterial pathogens including Pseudomonas aeruginosa, Staphylococcus aureus, and the non-tuberculous mycobacterium (NTM) Mycobacterium abscessus. The polymicrobial milieu within the CF lung impacts individual species fitness, influences biofilm-forming capabilities, pathogenicity, production of virulence factors and even antimicrobial responses, all potentially compromising therapeutic success. Interaction studies among these CF pathogens are very limited, especially studies on the influences of P. aeruginosa and S. aureus on M. abscessus co-existence and virulence. Based on the little known thus far about coinfection of these pathogens, we hypothesize that the co-existence of P. aeruginosa and S. aureus alters M. abscessus virulence and phenotypic characteristics. We evaluated the direct (co-culture) and indirect (using supernatant) effects of P. aeruginosa and S. aureus on M. abscessus growth rate, biofilm formation, macrophage internalization and glycopeptidolipids (GPL) expression. Our observations indicate that P. aeruginosa and S. aureus exert a competitive behavior toward M. abscessus during direct contact or indirect interaction in-vitro, probably as is the case of polymicrobial infections in the lungs of patients with CF. This is the first report that demonstrates S. aureus inhibitory effects on M. abscessus growth and biofilm forming capabilities. Collectively, co-culture studies enhance our understanding of polymicrobial interactions during coinfection and can guide to establish better management of coinfections and treatment strategies for M. abscessus.

The landscape of structural variation in aye-ayes (Daubentonia madagascariensis).

Aye-ayes (Daubentonia madagascariensis) are one of the 25 most critically endangered primate species in the world. Endemic to Madagascar, their small and highly fragmented populations make them particularly vulnerable to both genetic disease and anthropogenic environmental changes. Over the past decade, conservation genomic efforts have largely focused on inferring and monitoring population structure based on single nucleotide variants to identify and protect critical areas of genetic diversity. However, the recent release of a highly contiguous genome assembly allows, for the first time, for the study of structural genomic variation (deletions, duplications, insertions, and inversions) which are likely to impact a substantial proportion of the species' genome. Based on whole-genome, short-read sequencing data from 14 individuals, >1,000 high-confidence autosomal structural variants were detected, affecting ~240 kb of the aye-aye genome. The majority of these variants (>85%) were deletions shorter than 200 bp, consistent with the notion that longer structural mutations are often associated with strongly deleterious fitness effects. For example, two deletions longer than 850 bp located within disease-linked genes were predicted to impose substantial fitness deficits owing to a resulting frameshift and gene fusion, respectively; whereas several other major effect variants outside of coding regions are likely to impact gene regulatory landscapes. Taken together, this first glimpse into the landscape of structural variation in aye-ayes will enable future opportunities to advance our understanding of the traits impacting the fitness of this endangered species, as well as allow for enhanced evolutionary comparisons across the full primate clade.

Mutualistic interactions facilitate invasive species spread

Abstract Invasive species are major drivers of global ecosystem change. They often displace native species through competitive exclusion, creating novel species interactions. These interactions can lead to ecological cascades, where the presence of one invasive species enhances the fitness of another. Despite this, the mechanisms that underpin these mutualistic interactions and promote secondary invasions remain poorly understood. We assessed how the introduction of the invasive Argentine ant (Linepithema humile) alters mutualistic interactions within the recipient community, enhancing the dispersal and fitness of species of a secondary invasive plant genus (Acacia spp.). Our study examines these interactions at the community, individual species, and trait levels for a range of native and non‐native ant and plant species. Specifically, we aimed to investigate the direct and indirect effects of L. humile on seed dispersal mutualisms. We found that in L. humile invaded locations, seeds of the invasive Acacia plant species were approximately three times more likely to be dispersed than seeds of native endemic plant species. This preference is driven by indirect changes in the community structure of native seed‐dispersing ants, rather than direct interactions between the invasive ant and plant species. Moreover, we found that native ant species that co‐exist with L. humile, such as Tetramorium sericeiventre, respond to a narrower range of seed traits—traits which the invasive Acacia seeds possess. Our findings suggest that the invasion of L. humile has cascading effects on ant‐plant mutualisms, potentially increasing community permeability to secondary invasions. These results highlight that the impact of invaders like the Argentine ant may be greater than initially perceived, driving losses in both biological and functional plant diversity. Read the free Plain Language Summary for this article on the Journal blog.

Experimental species removal reveals species contributions to positive pollinator-mediated reproductive interactions.

Pollinator-mediated reproductive interactions among co-flowering plant species provide a canonical example of how biotic factors may contribute to species coexistence, yet we lack understanding of the exact mechanisms. Flowering-dominant and unusually attractive "magnet species" with disproportionate contributions to pollination may play key roles in such reproductive interactions, but their relative roles within the same community have rarely been assessed. We experimentally removed either a flowering-dominant or a highly attractive magnet species and compared effects on visitation frequency, pollinator richness, and seed set of co-flowering plants. Removal of either the flowering-dominant species or the magnet species reduced community-level pollinator visitation. Removal of the magnet species had the most consistent effect, including reduced pollinator visitation and richness, and reduced seed set of most co-flowering plants. These results suggest that the magnet species, which interacts with a wider range of pollinator species than does the dominant species, promotes the visitation and reproductive fitness of most other species. Removal of the flowering-dominant species affected only certain species, perhaps because these plants had floral traits similar to the dominant species. Our results highlight the role of attractive magnet species within a community in structuring reproductive interactions and identify potential mechanisms involved in coexistence facilitated by reproductive interactions.

Damage to the host cadaver, simulating the effects of scavenging, differentially affects fitness of entomopathogenic nematode species

Insect cadavers infected by entomopathogenic nematodes (EPN) are defended against scavengers by chemical mechanisms and other means. Despite these defences, the cadaver may be bitten before being rejected. In this study, we investigated the effect of damage to the cadaver cuticle on the fitness of nematodes (Heterorhabditis downesi Stock, Griffin & Burnell or Steinernema feltiae Filipjev) developing inside. We first quantified the severity of scavenger damage to EPN-infected Galleria mellonella Linnaeus cadavers in the field, and separately, with crickets (Gryllus bimaculatus De Geer) in the laboratory. In both field and laboratory, EPN-infected cadavers suffered less damage than freeze-killed controls, and damage consisted mainly of small lesions to the cuticle. In further experiments, scavenging damage was simulated shortly after death of infected cadavers by piercing the cuticle 0, 1, 3 or 5 times and incubating in moist (100% relative humidity (RH)) or dry (60–70% RH) conditions. The greater the level of damage, the greater the loss of moisture from the cadaver (estimated by weight loss), and this was exacerbated in dry conditions. The number of infective juveniles (IJs) emerging from H. downesi-infected cadavers was significantly reduced by damage, especially in dry conditions. In addition, emerging IJs were progressively smaller with increasing damage. For this species, the number of IJs was negatively correlated with moisture loss, indicating that the reduction in fitness was mediated by desiccation. For S. feltiae, damage impacted IJ number to a lesser extent and size was not affected. The reduction in numbers was not explained by moisture loss, indicating that for S. feltiae, some factor other than desiccation (perhaps competition with opportunistic microbes) impacts the nematodes when the cuticle is damaged. The greater vulnerability of H. downesi, compared to S. feltiae, to scavenger damage to the host cadaver may be due to its longer developmental time in the host resulting in longer exposure to damaging conditions. In conclusion, damage simulating biting by scavengers impacts the fitness of EPN, with the effect depending on nematode species, environmental conditions and the extent of damage. These findings have implications for the success of field application of EPN in infected cadavers.

Effective management of endangered Blanding’s Turtle (Emydoidea blandingii) populations in Nova Scotia, Canada, requires consideration of threats posed by legacy gold mine contamination

The Nova Scotia, Canada, Blanding’s turtle (Emydoidea blandingii) population is designated as endangered both federally and provincially. Currently, its range is confined to five disjunct sub-populations in the province’s southwestern interior. With fewer than 500 breeding adults in the wild, current recovery efforts are focused on reducing mortality risk to adult and juvenile turtles. However, little is being done to address the cumulative impacts of environmental contamination on species fitness and reproductive capacity. This paper focuses on legacy impacts of Nova Scotia’s gold mining industry within present-day Blanding’s turtle critical habitat, with a focus on mercury and arsenic contamination. To date, previous studies have not considered the impacts of legacy gold mining contaminants on Blanding’s turtle recovery and conservation. Three historical gold mining areas were identified as overlapping with Blanding’s turtle ranges (West Caledonia District, Brookfield District, and Pleasant River Barrens District). To address the current knowledge gap, site assessments for Blanding’s turtle presence, food web contamination surveys, turtle claw tissue sampling, and overall site remediation are recommended to complement existing recovery efforts. Keywords: Blanding’s turtle, critical habitat, environmental con-tamination, gold mine tailings

Fluctuating selection in a monkeyflower hybrid zone

Abstract While hybridization was viewed as a hindrance to adaptation and speciation by early evolutionary biologists, recent studies have demonstrated the importance of hybridization in facilitating evolutionary processes. However, it is still not well-known what role spatial and temporal variation in natural selection play in the maintenance of naturally occurring hybrid zones. To identify whether hybridization is adaptive between two closely related monkeyflower species, Mimulus guttatus and Mimulus laciniatus, we performed repeated reciprocal transplants between natural hybrid and pure species’ populations. We planted parental genotypes along with multiple experimental hybrid generations in a dry (2021) and extremely wet (2023) year in the Sierra Nevada, CA. By taking fine-scale environmental measurements, we found that the environment of the hybrid zone is more similar to M. laciniatus’s seasonally dry rocky outcrop habitat than M. guttatus’s moist meadows. In our transplants hybridization does not appear to be maintained by a consistent fitness advantage of hybrids over parental species in hybrid zones, but rather a lack of strong selection against hybrids. We also found higher fitness of the drought-adapted species, M. laciniatus, than M. guttatus in both species’ habitats, as well as phenotypic selection for M. laciniatus-like traits in the hybrid habitat in the dry year of our experiment. These findings suggest that in this system, hybridization might function to introduce drought-adapted traits and genes from M. laciniatus into M. guttatus, specifically in years with limited soil moisture. However, we also find evidence of genetic incompatibilities in second generation hybrids in the wetter year, which may balance a selective advantage of M. laciniatus introgression. Therefore, we find that hybridization in this system is both potentially adaptive and costly, and that the interaction of positive and negative selection likely determines patterns of gene flow between these Mimulus species.

Temporal variability in host availability alters the outcome of competition between two parasitoid species.

Variability in the availability of resources through time is a common attribute in trophic interactions, but its effects on the fitness of different consumer species and on interspecific competition between them are not clearly understood. To investigate this, we allowed two parasitoid species, Trichopria drosophilae and Pachycrepoideus vindemiae, to exploit Drosophila host pupae under different temporal variability treatments, either on their own or simultaneously. When tested individually (in the absence of interspecific competition), both parasitoid species had lower fitness when hosts were exposed for a short duration at high density than when exposed for a long duration at low density. When both parasitoid species exploited hosts simultaneously, interspecific competition significantly decreased the number of offspring for both parasitoid species. The outcome of this interspecific competition depended on host temporal variability, with T. drosophilae or P. vindemiae dominating in short and long host exposure treatments, respectively. These results can be explained by the combination of host availability and egg load of female adult parasitoids. When abundant hosts are provided for a short period, the ample mature eggs of the proovigenic T. drosophilae enable them to exploit hosts more efficiently than P. vindemiae, which is synovigenic. However, P. vindemiae is an intrinsically superior competitor and dominates when multiparasitism occurs. Multiparasitism is more frequent when hosts are at low levels relative to the egg load of the parasitoids. Our results clearly demonstrate that resource temporal availability can alter the outcome of competition between consumers with different reproductive traits.

Environmentally acquired gut-associated bacteria are not critical for growth and survival in a solitary bee, Megachile rotundata.

Social bees have been extensively studied for their gut microbial functions, but the significance of the gut microbiota in solitary bees remains less explored. Solitary bee, Megachile rotundata females provision their offspring with pollen from various plant species, harboring a diverse microbial community that colonizes larvae guts. The Apilactobacillus is the most abundant microbe, but evidence concerning the effects of Apilactobacillus and other provision microbes on growth and survival are lacking. We hypothesized that the presence of Apilactobacillus in abundance would enhance larval and prepupal development, weight, and survival, while the absence of intact microbial communities was expected to have a negative impact on bee fitness. We reared larvae on pollen provisions with naturally collected microbial communities (Natural pollen) or devoid of microbial communities (Sterile pollen). We also assessed the impact of introducing Apilactobacillus micheneri by adding it to both types of pollen provisions. Feeding larvae with sterile pollen + A. micheneri led to the highest mortality rate, followed by natural pollen + A. micheneri, and sterile pollen. Larval development was significantly delayed in groups fed with sterile pollen. Interestingly, larval and prepupal weights did not significantly differ across treatments compared to natural pollen-fed larvae. 16S rRNA gene sequencing found a dominance of Sodalis, when A. micheneri was introduced to natural pollen. The presence of Sodalis with abundant A. micheneri suggests potential crosstalk between both, shaping bee nutrition and health. Hence, this study highlights that the reliance on nonhost-specific environmental bacteria may not impact fitness of M. rotundata.IMPORTANCEThis study investigates the impact of environmentally acquired gut microbes of solitary bee fitness with insights into the microbial ecology of bee and their health. While the symbiotic microbiome is well-studied in social bees, the role of environmental acquired microbiota in solitary bees remains unclear. Assessing this relationship in a solitary pollinator, the leaf-cutting bee, Megachile rotundata, we discovered that this bee species does not depend on the diverse environmental bacteria found in pollen for either its larval growth or survival. Surprisingly, high concentrations of the most abundant pollen bacteria, Apilactobacillus micheneri did not consistently benefit bee fitness, but caused larval mortality. Our findings also suggest an interaction between Apilactobacillus and the Sodalis and perhaps their role in bee nutrition. Hence, this study provides significant insights that contribute to understanding the fitness, conservation, and pollination ecology of other solitary bee species in the future.

Is mating failure caused by cryptic male choice in the seed bug Lygaeus simulans?

One yet unresolved question in the study of mating system evolution is the occurrence of mating failure, when individuals go through their lives without successfully mating. This includes the failure to produce offspring even following copulation, for instance due to insemination or fertilisation failure. Copulations are costly in a variety of ways, but also a fundamental route to fitness in sexual species, and so we should expect that engaging in copulations that generate no offspring should be strongly selected against. Nonetheless, it has become apparent that mating failure is quite common in nature. Here we consider post-copulatory sexual selection in Lygaeus simulans seed bugs to test the hypothesis that the high levels of mating failure found in this species (approximately 40%-60%) are caused by cryptic male choice (i.e. males choosing not to inseminate a female during copulation). In our first experiment, we found that mating failure depended on female size, but not male size, with smaller females experiencing mating failure more frequently. Mechanistically this is likely to be due to copulation duration, as shorter copulations were more likely to lead to mating failure. Likewise, copulations with smaller females were shorter. In our second and third experiments, rates of mating failure decreased when pairs were allowed to repeatedly interact with the same partner over longer durations (hours through to days), implying that mating failure is not primarily caused by infertility or chronic mechanical failure. Instead, our results strongly suggest cryptic male choice as the cause of mating failure in this species.

Towards the conservation of the crucian carp in Europe: Prolific hybridization but no evidence for introgression between native and non-native taxa.

Hybridization plays a pivotal role in evolution, influencing local adaptation and speciation. However, it can also reduce biodiversity, which is especially damaging when native and non-native species meet. Hybridization can threaten native species via competition (with vigorous hybrids), reproductive resource wastage and gene introgression. The latter, in particular, could result in increased fitness in invasive species, decreased fitness of natives and compromise reintroduction or recovery conservation practices. In this study, we use a combination of RAD sequencing and microsatellites for a range-wide sample set of 1366 fish to evaluate the potential for hybridization and introgression between native crucian carp (Carassius carassius) and three non-native taxa (Carassius auratus auratus, Carassius auratus gibelio and Cyprinus carpio) in European water bodies. We found hybridization between native and non-native taxa in 82% of populations with non-natives present, highlighting the potential for substantial ecological impacts from hybrids on crucian carp populations. However, despite such high rates of hybridization, we could find no evidence of introgression between these taxa. The presence of triploid backcrosses in at least two populations suggests that the lack of introgression among these taxa is likely due to meiotic dysfunction in hybrids, leading to the production of polyploid offspring which are unable to reproduce sexually. This result is promising for crucian reintroduction programs, as it implies limited risk to the genetic integrity of source populations. Future research should investigate the reproductive potential of triploid hybrids and the ecological pressures hybrids impose on C. carassius.

Synopsis of Akamboja (Coleoptera: Phengodidae): new species, synonym, new records and remarks on abdominal morphology for the genus.

Akamboja Roza et al., 2017 (Phengodidae: Mastinocerinae) was described to include five species, all from Atlantic Forest, which are characterized by having ten segmented antennae, biflabellate from antennomeres IV-VIII, and with fused flabellae on antennomere IX. The genus comprises six species today, including one from Ilha Grande (Angra dos Reis, Rio de Janeiro State, Brazil) with the IX antennomere flabellae not fused. In this paper, we describe seven new species based on specimens from seven entomological collections: Akamboja ganhoae sp. nov., Akamboja kumagaiae sp. nov., Akamboja microphthalmus sp. nov., Akamboja peckorum sp. nov., Akamboja piauiensis sp. nov., Akamboja planautensis sp. nov., and Akamboja wittmeri sp. nov. These new species include new biome records for Brazil (Cerrado, Caatinga and Amazonia), and the first species of the genus from Venezuela and Argentina. The seven new species fit in the genus diagnosis, but presents an antennal morphological variation in the flabellae of the antennomere VIII-IX: fusion of flabellae in antennomeres IX, in both antennomeres VIII and IX, or the absence of any fusion in any flabellae. Based on this variation, we propose an updated diagnosis for the genus. We also discuss and propose Akamboja caparaoensis Roza et al., 2017 as a new junior synonym of Akamboja cleidae Roza et al., 2017, and provide new distributional records for A. minimum Roza et al., 2017 and A. insularis Roza et al., 2018. Additionally, we describe for the first time in the genus the abdominal membranous projection present in several Mastinocerinae, but previously ignored, as well as the morphology of tergites IX, and X, and sternite IX.

Diameter growth models and performance of 100 tropical tree species in silvicultural trials in Brazil

Projects of reforestation for sustainable production of tropical timber and for nature-based solutions must be based on reliable growth models. However, there is still a big gap in knowledge about the growth in diameter for native and exotic tropical timber species. Here, we used diameter growth data from 100 tropical tree species in silvicultural experiments established from the late 1970s to the early 1990s in the Vale Natural Reserve in the north of Espírito Santo state, Brazil. Plantations were periodically measured, usually over 20–30 years, which allowed us to produce growth models for all species and recommend those that can help boost silviculture in Brazil. We also used the data to test a large set of tree species against the same set of models, to assess model’s performance. Among 71 native species studied, 31 % showed slow growth (MAI < 0.70 cm/yr), 40 % medium growth (0.70≤ MAI < 0.97 cm/yr) and 29 % high growth (MAI ≥ 0.97 cm/yr), while 47 % of the 29 exotic species showed high growth rates. Based on our analysis, we recommend the use of Korf, Levakovik II, Hossfeld IV, and Levakovic III models for growth studies, because they showed a better fit for most species or because they were plausible competitor models. Even though many species have shown a great performance for silvicultural projects, more experimental trials must be established in different site and management conditions, to fully explore the silvicultural potential of these tropical timber species.

Fitness consequences of population bottlenecks in an invasive blowfly.

Invasive species often undergo demographic bottlenecks that cause a decrease in genetic diversity and associated reductions in population fitness. Despite this, they manage to thrive in novel environments. Investigating the effects of inbreeding and genetic bottlenecks on population fitness for invasive species is, therefore, key to understanding how they may survive in new environments. We used the blowfly Calliphora vicina (Sciences, Mathématiques et Physique, 1830, 2, 1), which is native to Europe and was introduced to Australia and New Zealand, to examine the effects of genetic diversity on population fitness. We first collected 59 samples from 15 populations across New Zealand and one in Australia, and used 20,501 biallelic SNPs to investigate population genomic diversity, structure and admixture. We then explored the impacts of repeated experimental bottlenecks on population fitness by creating inbred and outbred lines of C. vicina and measuring a variety of fitness traits. In wild-caught samples, we found low overall genetic diversity, signals of genetic admixture and limited (<3%) genetic differentiation between North and South Island populations, with genetic links between the South Island and Australia. Following experimental bottlenecks, we found significant reductions in fitness for inbred lines. However, fitness effects were not felt equally across all phenotypic traits. Moreover, they were not enough to cause population collapse in any experimental line, suggesting that C. vicina (when under relaxed selection, as in laboratory settings) may be able to compensate for population bottlenecks even when highly inbred. Our results demonstrate the value of a tractable experimental system for investigating processes that may facilitate or hamper biological invasion.

Fungal primary and opportunistic pathogens: an ecological perspective.

Fungal primary pathogenicity on vertebrates is here described as a deliberate strategy where the host plays a role in increasing the species' fitness. Opportunism is defined as the coincidental survival of an individual strain in host tissue using properties that are designed for life in an entirely different habitat. In that case, the host's infection control is largely based on innate immunity, and the etiologic agent is not transmitted after infection, and thus fungal evolution is not possible. Primary pathogens encompass two types, depending on their mode of transmission. Environmental pathogens have a double life cycle, and tend to become enzootic, adapted to a preferred host in a particular habitat. In contrast, pathogens that have a host-to-host transmission pattern are prone to shift to a neighboring, immunologically naive host, potentially leading to epidemics. Beyond these prototypical life cycles, some environmental fungi are able to make large leaps between dissimilar hosts/habitats, probably due to the similarity of key factors enabling survival in an entirely different niche, and thus allowing a change from opportunistic to primary pathogenicity. Mostly, such factors seem to be associated with extremotolerance.

The complex effects of modern oncogenic environments on the fitness, evolution and conservation of wildlife species.

Growing evidence indicates that human activities are causing cancer rates to rise in both human and wildlife populations. This is due to the inability of ancestral anti-cancer defences to cope with modern environmental risks. The evolutionary mismatch between modern oncogenic risks and evolved cancer defences has far-reaching effects on various biological aspects at different timeframes, demanding a comprehensive study of the biology and evolutionary ecology of the affected species. Firstly, the increased activation of anti-cancer defences leads to excessive energy expenditure, affecting other biological functions and potentially causing health issues like autoimmune diseases. Secondly, tumorigenesis itself can impact important fitness-related parameters such as competitiveness, predator evasion, resistance to parasites, and dispersal capacity. Thirdly, rising cancer risks can influence the species' life-history traits, often favoring early reproduction to offset fitness costs associated with cancer. However, this strategy has its limits, and it may not ensure the sustainability of the species if cancer risks continue to rise. Lastly, some species may evolve additional anti-cancer defences, with uncertain consequences for their biology and future evolutionary path. In summary, we argue that the effects of increased exposure to cancer-causing substances on wildlife are complex, ranging from immediate responses to long-term evolutionary changes. Understanding these processes, especially in the context of conservation biology, is urgently needed.

Phenotypic correlates between clock genes and phenology among populations of Diederik cuckoo, Chrysococcyx caprius.

The Diederik cuckoo, Chrysococcyx caprius, is a small Afrotropical bird in the family Cuculidae. It is taxonomically related to 13 other species within the genus Chrysococcyx and is migratory in sub-Saharan Africa. It has a unique breeding behaviour of being a brood parasite: Breeding pairs lay their eggs in the nests of a host species and hatchlings expel the eggs of the host species. The aim of the present study was to investigate diversity in two circadian clock genes, Clock and Adcyap1, to probe for a relationship between genetic polymorphisms and their role in circannual timing and habitat selection (phenology) in intra-African migrants. DNA extracted from blood was used for the PCR amplification and sequencing of clock genes in 30 Diederik cuckoos. Three alleles were detected for Clock with similar genotypes between individuals from the Northern and Southern breeding ranges while 10 alleles were detected for Adcyap1, having shorter alleles in the North and longer alleles in the South. Population genetic analyses, including allele frequency and zygosity analysis, showed distinctly higher frequencies for the most abundant Clock allele, containing 10 polyglutamine repeats, as well as a high degree of homozygosity. In contrast, all individuals were heterozygous for Adcyap1 and alleles from both regions showed distinct differences in abundance. Comparisons between both clock genes and phenology found several phenotypic correlations. This included evidence of a relationship between the shorter alleles and habitat selection as well as a relationship between longer alleles and timing. In both instances, evidence is provided that these effects may be sex-specific. Given that these genes drive some of the synchronicity between environments and the life cycles of birds, they provide valuable insight into the fitness of species facing global challenges including climate change, urbanisation and expanding agricultural practices.

Basic Research on Candida Species.

Candida species are common human pathogens that cause a wide range of diseases ranging from superficial to invasive candidiasis. However, basic studies focusing on the mechanisms underlying these diseases are limited. This article reviews our previous research on the mechanisms of superficial and invasive candidiasis, the virulence of Candida species, and Candida species fitness to hosts. Regarding invasive candidiasis, we focused on two types of infections: ocular candidiasis and endogenous candidiasis from the gastrointestinal tract. Using an established ocular candidiasis mouse model, along with retrospective epidemiological research, we found a strong association between Candida albicans and ocular candidiasis. Regarding endogenous candidiasis, research using Candida auris indicated that invasive strains had a higher capability for gastrointestinal tract colonization and showed greater dissemination compared with non-invasive strains. In terms of superficial candidiasis, we focused on the defense mechanism in vulvovaginal candidiasis. The results suggested that stimulated invariant natural killer T cells played a protective role against C. albicans vaginal infection and might be a therapeutic target for vulvovaginal candidiasis. Concerning Candida species fitness, we focused on environmental factors, particularly oxygen concentration, and evaluated biofilm formation under various oxygen concentrations, revealing that each Candida species favored different oxygen concentrations. In particular, Candida tropicalis showed greater biofilm formation under hypoxic conditions. Our research revealed several insights for understanding the exact mechanisms of candidiasis, which might lead to better control of Candida species infections and appropriate treatment.