BMC ecology and evolution最新文献

Background: Semi-aquatic mammals represent a transitional phase in the evolutionary spectrum between terrestrial and aquatic mammals. The sense of balance is crucial for mammalian locomotion, and in semi-aquatic mammals, the structural foundation of this sense (the vestibular system) shows distinct morphological adaptations to both aquatic and terrestrial environments compared to their terrestrial counterparts. Despite this, the precise molecular mechanisms driving these adaptations remain elusive. Our study endeavors to unravel the genetic components associated with the sense of balance in semi-aquatic mammals and to examine the evolutionary trajectories of these genes, shed light on the molecular mechanisms underlying the adaptive evolution of balance perception in semi-aquatic mammals.

Results: We selected 42 mammal species across 20 orders, 38 families, and 42 genera for analysis. We analyzed a comprehensive set of 116 genes related to the vestibular system's development or function. Our findings indicate that 27 of these genes likely experienced adaptive evolution in semi-aquatic mammals. Particularly, genes such as SLC26A2, SOX10, MYCN, and OTX1 are implicated in collectively orchestrating morphological adaptations in the semicircular canals to suit semi-aquatic environments. Additionally, genes associated with otolith development, including SLC26A2, OC90, and OTOP1, likely regulate otolith sensitivity across various locomotor modes. Moreover, genes linked to vestibular disorders, such as GJB2, GJB6, and USH1C, may provide a molecular foundation for averting vertigo amidst intricate locomotor scenarios in semi-aquatic mammals.

Conclusions: Our research offers insights into the molecular mechanisms underlying the evolution of the sense of balance in semi-aquatic mammals, while also providing a new research direction for the adaptive evolution of mammals undergoing a secondary transition to an aquatic lifestyle.

Caves are one of the most exciting environments on earth, often considered an evolutionary laboratory due to the suite of convergent adaptive traits (troglomorphisms) of organisms inhabiting them. Sinonychia martensi Zhang & Derkarabetian, 2021, is the first and only Travunioidea species recorded in China and is endemic to Beijing, being known from multiple caves. However, nothing is known regarding its phylogeographic or evolutionary history. In this study, we assessed the species boundaries of S. martensi from nine caves using morphological and molecular methods to elucidate its phylogenetic position and genealogical relationships. We also investigated the genetic diversity, population genetic structure and demographic history of S. martensi to clarify the population-level relationships and make inferences about historical phylogeography. The results indicate that the species from different caves all belonged to S. martensi but represent different populations. These populations exhibit strong population structure and low genetic diversity. Cave populations may share a common ancestor and multiple independent invasions to different caves. The diversification within S. martensi was likely driven by climate change and subtropical evergreen broadleaf forests associated with the middle Miocene. This study highlights the need for further conservation efforts and exploration in Beijing caves.

Background: Protein evolution is central to molecular adaptation and largely characterized by modular rearrangements of domains, the evolutionary and structural building blocks of proteins. Genetic events underlying protein rearrangements are relatively rare compared to changes of amino-acids. Therefore, these events can be used to characterize and reconstruct major events of molecular adaptation by comparing large data sets of proteomes.

Results: Here we determine, at unprecedented completeness, the rates of fusion, fission, emergence and loss of domains in five eukaryotic clades (monocots, eudicots, fungi, insects, vertebrates). By characterizing rearrangements that were previously considered "ambiguous" or "complex" we raise the fraction of resolved rearrangement events from previously ca. 60% to around 92%. We exemplify our method by analyzing the evolutionary histories of protein rearrangements in (i) the extracellular matrix, (ii) innate immunity across Eukaryota, Metazoa, and Vertebrata, and (iii) Toll-Like-Receptors in the innate immune system of Eukaryota. In all three cases we can find hot-spots of rearrangement events in their phylogeny which (i) can be related with major events of adaptation and (ii) which follow the emergence of new domains which become integrated into existing arrangements.

Conclusion: Our results demonstrate that, akin to the change at the level of amino acids, domain rearrangements follow a clock-like dynamic which can be well quantified and supports the concept of evolutionary tinkering. While many novel domain emergence events are ancient, emerged domains are quickly incorporated into a great number of proteins. In parallel, the observed rates of emergence of new domains are becoming smaller over time.

Background: The destructive human activities, encroachment of natural habitats, and hyperarid climate threaten the wild flora of the unprotected mountainous areas facing the Gulf of Suez, Egypt. So, this study aims to revise and give an updated systematic status of the flowering plants growing there to conserve and utilize valuable biodiversity.

Results: This study showed the presence of 136 species, including 7 sub-species of vascular plants, 12 species of monocots, and 124 species dicots belonged to 98 genera and 37 families. The most species-rich families were Asteraceae (22 species) and Amaranthaceae (19 species). Therophytes and Chamaephytes were the most dominant life- forms in the study area, representing 38.2%. They were followed by Phanerophytes, Hemicryptophytes, and Cryptophytes, which represented 11%, 8.8%, and 2.9%, respectively. Five plant assemblages were identified by TWINSAPN classification namely, Zygophyllum coccineum -Haloxylon salicornicum assemblage, Zilla spinosa -Zygophyllum coccineum assemblage, Zygophyllum coccineum-Tamarix nilotica assemblage, Tamarix nilotica - Phargmites australis assemblage and Tamarix nilotica-Chenopodium murale assemblage. Several invasive species were recorded in some wadis. However, their presence is unusual to the floristic composition of the wadis in general and acts as an alarm to protect the native species from anthropogenic interference. Moisture content, organic matter, electrical conductivity, pH, cations, anions, and total carbonate were identified as the significant factors controlling distribution of plant clusters by detrended correspondence analysis. This study recorded Tribulus mollis as a new addition to Egypt's flora of Eastern desert.

Conclusion: The comparative analysis of the present and past floral studies in the study area reveals a significant change in the plant community composition. This shift is likely attributed to the adverse impacts of climate change and anthropogenic activities. Thus, this area has to be safeguarded with practical strategies that aid in preserving the significant uncommon flora.

Background: Global warming and extreme weather events driven by greenhouse gas emissions are significantly impacting fish survival and reproduction, leading to dramatic consequences for marine biodiversity and ecosystem stability. Comparative analysis of closely related species from a phylogenetic perspective provides valuable insights for biodiversity conservation efforts. The study investigates the effects of climate change on the suitability of habitat and ecological vulnerability of two important sibling fishes, Collichthys lucidus and Collichthys niveatus, in the western Pacific.

Results: This study found that the main driver of ecological niche differences between the two species is the niche contraction of C. niveatus. Predictions from species distribution models indicate that C. lucidus has a wider distribution and greater adaptability under future climate scenarios. Both species will experience significant habitat loss and heightened ecological vulnerability in the southern Yellow Sea. Additionally, the two populations of C. lucidus in the Yangtze River estuary display different levels of ecological vulnerability. These two species also exhibit distinct responses to environmental factors such as temperature and chlorophyll concentration.

Conclusion: The study's findings indicate that climate change will accelerate the population differentiation of C. lucidus and the habitat loss of C. niveatus. These results underscore the importance of prioritizing the southern Yellow Sea in future research and emphasize the necessity of developing adaptive conservation strategies for both species.

Lygodactylus geckos represent a well-documented radiation of miniaturized lizards with diverse life-history traits that are widely distributed in Africa, Madagascar, and South America. The group has diversified into numerous species with high levels of morphological similarity. The evolutionary processes underlying such diversification remain enigmatic, because species live in different ecological biomes, ecoregions and microhabitats, while suggesting strikingly high levels of homoplasy. To underscore this evolutionary pattern, here we explore the shape variation of skull elements (i.e., cranium, jaw and inner ear) using 3D geometric morphometrics and phylogenetic comparative methods on computed tomography scans (CT-scan) of a sample encompassing almost all recognized taxa within Lygodactylus. The results of this work show that skull and inner ear shape variation is low (i.e., there is high overlapping on the morphospace) across geographic regions, macrohabitats and lifestyles, implying extensive homoplasy. Furthermore, we also found a strong influence of allometry shaping cranial variation both at intra and interspecific levels, suggesting a major constraint underlying skull architecture, probably as a consequence of its miniaturization. The remaining variation that is not allometric is independent of phylogeny and ecological adaptation and can probably be interpreted as the result of intrinsic developmental plasticity. This, in turn, supports the interpretation that speciation in this group is largely concordant with a non-adaptive hypothesis, which results mainly from vicariant processes.

Background: Citizen Science (CS) offers a promising approach to enhance data collection and engage communities in conservation efforts. This study evaluates the use of CS in environmental DNA (eDNA) monitoring for Mediterranean monk seal conservation. We validated CS by assessing the effectiveness of a newly developed CS-friendly filtration system called "WET" (Water eDNA Trap) in eDNA detection, addressing technical challenges, and analysing volunteer faults. The WET is a 4-litre, manual pump-based filtering system using positive pressure to force water through the filter. We also assessed the use of a retrospective questionnaire as a tool to measure CS's social impact on participants' perceived knowledge, attitudes, and conservation behaviours.

Results: Results suggest the WET performs comparably to traditional methods, with minor technical issues. Despite some faults such as not folding or forgetting to change the filter, volunteers were generally reliable in sample processing. Moreover, CS involvement increased participants' perceived knowledge, affective attitudes, and conservation behaviours towards seal conservation. Volunteers reported a greater understanding of eDNA monitoring, increased interest in monk seal conservation, and more frequent conservation behaviours, including spreading awareness within their community. While these findings are exploratory due to the small sample size (19 participants) and potential ceiling effects in attitude assessment, they provide an initial validation of the questionnaire as a tool for measuring CS's social outcomes. Future studies with larger sample sizes are needed to confirm these results and investigate their applicability across broader stakeholder groups. Continuous improvement in volunteer training and equipment design is also recommended.

Conclusions: This study highlights CS's potential to improve public engagement and knowledge in conservation. By involving diverse participants, CS can play a critical role in long-term conservation efforts and promote sustainable coexistence between humans and monk seals. Furthermore, the validation of the questionnaire offers a valuable framework for evaluating the social impact of CS initiatives in conservation contexts.

Background: Understanding local communities' knowledge and insights is essential for developing effective mitigation and adaptation strategies for climate change. The young generation often brings new perspectives on climate change, demonstrating a growing awareness of its impacts and innovative ideas for sustainable solutions. By engaging youth in climate action we foster future leadership, empowering them as active participants in shaping long-term climate resilience. Higher education plays a pivotal role in raising awareness about climate change and fostering environmentally responsible behaviour among citizens. Thus, the study assessed climate change indicators in Tanzania by gathering insights from university students, leveraging their understanding of the local challenges posed by climate change.

Results: Out of the 486 sampled students, 80% were aware of climate change and could identify its indicators in their home regions. The primary perceived indicators of climate change reported by the respondents included increasing temperatures, crop failures, and the disappearance of native plant species. Respondents from the coastal zone ranked rising temperatures and increased rainfall as the most significant indicators, while those from the Kilimanjaro region emphasised crop failure. Additionally, respondents from the central zone highlighted the disappearance of native plant species. Conversely, respondents from the arid central zone believed that climate change has resulted in reduced rainfall and an increase in drought occurrences. Furthermore, socio-demographic factors such as gender, home region, and academic year influenced students' awareness of climate change. A lower proportion (0.78) of male students demonstrated knowledge of climate change compared to female students (0.91) (p = 0.001). Additionaly, a lower proportion (0.71) of students from urban areas demonstrated knowledge of climate change compared to students from rural areas (0.85) (p < 0.001). Moreover, students in their final year of study exhibited greater awareness of climate change than those in lower years, highlighting the significance of the formal education system in imparting knowledge about climate change.

Conclusions: This study underscores the role of higher education in fostering climate awareness and youth engagement through education and outreach. Additionally, it supports SDG 13: "Climate Action" and SDG 4: "Quality Education by promoting informed participation and sustainable solutions among young people".

Background: The spotted hyena (Crocuta crocuta) is one of the carnivore species that frequently comes into conflict with humans. These conflicts are attributed to their scavenging foraging behaviour and their ability to occupy habitats close to human settlements. In Tanzania, the Geita region has recently experienced an increase in livestock and human attacks by hyenas. However, there are limited studies examining the extent of these attacks and the associated social-economic impacts. Thus, this study evaluated the social impacts and economic losses due to spotted hyena attacks in the Nyang'whale district in the Geita region.

Materials and methods: The study was carried out in three villages in the Nyang'whale district, namely Wavu, which is close to the Mienze Forest Reserve; Bukungu, which is far from the forest but surrounded by many hills; and Izunya, which is far from the forest and the hills. Data collection was done through household surveys, focus group discussions, and key informant interviews. A Chi-square test assessed the association between hyena fear and daily activities across villages. Poisson regression compared the number of livestock attacked by hyenas by village and species. Linear regression analysis compared financial losses due to livestock attacks and reductions in working time due to hyena fear across villages.

Results: There was a significant variation in the frequency of livestock and human attacks between the villages. The frequency of livestock attacks was lower in Bukungu village, but human attacks were highest in this village. The Wavu village, which is close to the forest, had the highest livestock number and attacks, but no human attacks were reported. The hyena attacks had created fear, which had changed the daily routines of the villagers. The village with the most human attacks reported a high rate of school dropouts, while the one with the most livestock attacks reported a reduction in sleeping time at night to watch livestock. Economic losses due to livestock attacks averaged $300.5 per household per year, while losses due to reduced working time were equivalent to $285.6 per household per year.

Conclusion: Given that villages with a large number of livestock experienced more livestock attacks and fewer human attacks, this suggests that hyenas may target humans when their food resources are limited. Therefore, conducting further studies to assess the hyena population and the availability of their natural prey is crucial for formulating effective intervention strategies. Additionally, villagers should be educated on ways to control human and livestock attacks based on the animals' ecology and behaviour.