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1. Evaluating modularity in the hominine skull related to feeding biomechanics

   https://doi.org/10.1002/ajpa.24875  

   Jung, Hyunwoo; Strait, David; Rolian, Campbell; Baab, Karen L. (November 2023, American Journal of Biological Anthropology)

   Abstract ObjectivesModular architecture of traits in complex organisms can be important for morphological evolution at micro‐ and sometimes macroevolutionary scales as it may influence the tempo and direction of changes to groups of traits that are essential for particular functions, including food acquisition and processing. We tested several distinct hypotheses about craniofacial modularity in the hominine skull in relation to feeding biomechanics. Materials and MethodsFirst, we formulated hypothesized functional modules for craniofacial traits reflecting specific demands of feeding biomechanics (e.g., masseter leverage/gape or tooth crown mechanics) inHomo sapiens,Pan troglodytes, andGorilla gorilla. Then, the pattern and strength of modular signal was quantified by the covariance ratio coefficient and compared across groups using covariance ratio effect size. Hierarchical clustering analysis was then conducted to examine whether a priori‐defined functional modules correspond to empirically recovered clusters. ResultsThere was statistical support for most a priori‐defined functional modules in the cranium and half of the functional modules in the mandible. Modularity signal was similar in the cranium and mandible, and across the three taxa. Despite a similar strength of modularity, the empirically recovered clusters do not map perfectly onto ourpriorifunctional modules, indicating that further work is needed to refine our hypothesized functional modules. ConclusionThe results suggest that modular structure of traits in association with feeding biomechanics were mostly shared with humans and the two African apes. Thus, conserved patterns of functional modularity may have facilitated evolutionary changes to the skull during human evolution. 

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2. Evolutionary history and environmental variability structure contemporary tropical vertebrate communities

   https://doi.org/10.1111/geb.13829  

   Hsieh, Chia; Gorczynski, Daniel; Bitariho, Robert; Espinosa, Santiago; Johnson, Steig; Lima, Marcela Guimarães Moreira; Rovero, Francesco; Salvador, Julia; Santos, Fernanda; Sheil, Douglas; et al (March 2024, Global Ecology and Biogeography)

   Abstract AimTropical regions harbour over half of the world's mammals and birds, but how their communities have assembled over evolutionary timescales remains unclear. To compare eco‐evolutionary assembly processes between tropical mammals and birds, we tested how hypotheses concerning niche conservatism, environmental stability, environmental heterogeneity and time‐for‐speciation relate to tropical vertebrate community phylogenetic and functional structure. LocationTropical rainforests worldwide. Time periodPresent. Major taxa studiedGround‐dwelling and ground‐visiting mammals and birds. MethodsWe used in situ observations of species identified from systematic camera trap sampling as realized communities from 15 protected tropical rainforests in four tropical regions worldwide. We quantified standardized phylogenetic and functional structure for each community and estimated the multi‐trait phylogenetic signal (PS) in ecological strategies for the four regional species pools of mammals and birds. Using linear regression models, we test three non‐mutually exclusive hypotheses by comparing the relative importance of colonization time, palaeo‐environmental changes in temperature and land cover since 3.3 Mya, contemporary seasonality in temperature and productivity and environmental heterogeneity for predicting community phylogenetic and functional structure. ResultsPhylogenetic and functional structure showed non‐significant yet varying tendencies towards clustering or dispersion in all communities. Mammals had stronger multi‐trait PS in ecological strategies than birds (mean PS: mammal = 0.62, bird = 0.43). Distinct dominant processes were identified for mammal and bird communities. For mammals, colonization time and elevation range significantly predicted phylogenetic clustering and functional dispersion tendencies respectively. For birds, elevation range and contemporary temperature seasonality significantly predicted phylogenetic and functional clustering tendencies, respectively, while habitat diversity significantly predicted functional dispersion tendencies. Main conclusionsOur results reveal different eco‐evolutionary assembly processes structuring contemporary tropical mammal and bird communities over evolutionary timescales that have shaped tropical diversity. Our study identified marked differences among taxonomic groups in the relative importance of historical colonization and sensitivity to environmental change. 

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3. Review on functional data classification

   https://doi.org/10.1002/wics.1638  

   Wang, Shuoyang; Huang, Yuan; Cao, Guanqun (January 2024, WIREs Computational Statistics)

   Abstract A fundamental problem in functional data analysis is to classify a functional observation based on training data. The application of functional data classification has gained immense popularity and utility across a wide array of disciplines, encompassing biology, engineering, environmental science, medical science, neurology, social science, and beyond. The phenomenal growth of the application of functional data classification indicates the urgent need for a systematic approach to develop efficient classification methods and scalable algorithmic implementations. Therefore, we here conduct a comprehensive review of classification methods for functional data. The review aims to bridge the gap between the functional data analysis community and the machine learning community, and to intrigue new principles for functional data classification. This article is categorized under:Statistical Learning and Exploratory Methods of the Data Sciences > Clustering and ClassificationStatistical Models > Classification ModelsData: Types and Structure > Time Series, Stochastic Processes, and Functional Data 

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4. Temperature seasonality drives taxonomic and functional homogenization of tropical butterflies

   https://doi.org/10.1111/ddi.13814  

   Hulshof, Catherine M.; Ackerman, James D.; Franqui, Rosa A.; Kawahara, Akito Y.; Restrepo, Carla (January 2024, Diversity and Distributions)

   Abstract AimTo better understand the potential impact of climate change on butterfly assemblages across a tropical island, we model the potential for taxonomic and functional homogenization and determine climate‐ and trait‐mediated shifts in projected species distributions. LocationPuerto Rico. MethodsWe used thousands of museum records of diurnal Lepidoptera to model current (1970–2000) and forecast future (2061–2080) species distributions and combined these to test for taxonomic and functional homogenization. We then quantified climatic‐mediated effects on current and forecasted taxonomic and functional composition and, specifically, whether temperature was a primary driver, as predicted by the temperature–size rule and the thermal melanism hypotheses. Finally, we measured wing traits important in thermoregulation (size and colour) and determined trait‐mediated changes in forecasted species distributions over time. ResultsBased on ensemble model outputs, taxonomic and functional richness and turnover were predicted to vary across the island's complex topography. Our models projected an increase in taxonomic and functional richness over time, and a decrease in taxonomic and functional turnover – a signature of biotic homogenization. Under future climate scenarios, models projected a decrease in wing length and an increase in wing brightness at higher elevations. One variable, temperature seasonality, was the strongest predicted driver of both the current spatial distribution and the projected per cent change over time for not only wing traits but also taxonomic and functional richness and turnover. Main conclusionsThe species distribution models generated here identify several priority regions and species for future research and conservation efforts. Our work also highlights the role of seasonality and climatic variability on diverse tropical Lepidoptera assemblages, suggesting that climatic variability may be an important, albeit overlooked, driver of climate change responses. 

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5. Does island ontogeny dictate the accumulation of both species richness and functional diversity?

   https://doi.org/10.1111/geb.13420  

   Kraemer, Andrew C.; Roell, Yannik E.; Shoobs, Nate F.; Parent, Christine E. (October 2021, Global Ecology and Biogeography)

   Abstract AimThe accumulation of functional diversity in communities is poorly understood. Conveniently, the general dynamic model of island biogeography (GDM) makes predictions for how such diversity might accumulate over time. In this multiscale study of land snail communities on 10 oceanic archipelagos located in various regions of the globe, we test hypotheses of community assembly in systems where islands serve as chronosequences along island ontogeny. LocationTen volcanic archipelagos. Time periodFrom 23 Ma to the present. Major taxa studiedEndemic land snails. MethodsInitially, we assembled geological island characteristics of area, isolation and ontogeny for all studied islands. We then characterized island‐scale biotic variables, including the species diversity and functional diversity of snail communities. From these data, we assessed relationships between island and snail community variables as predicted by the GDM, focusing initially on the islands of the Galápagos archipelago and thereafter with a broader analysis of 10 archipelagoes. ResultsAs in other studies of island assemblages, in Galápagos we find a hump‐shaped curve of species richness, with depauperate snail faunas on early‐ontogeny islands, increasing species richness on mid‐ontogeny islands and low species richness on islands in late ontogeny. We find exceptionally low functional diversity on early‐ontogeny islands that increases through mid‐ontogeny, whereas late‐ontogeny islands exhibit a range of functional diversity. The analysis including all 10 archipelagos indicates a major role of archipelago‐specific factors. In both sets of analyses, functional diversity is exceptionally low on early‐ontogeny islands, and island ontogeny is a significant predictor of morphology. Main conclusionsConsistent patterns of functional diversity across island ontogeny on all examined archipelagos indicate a common role for habitat filtering, ecological opportunity and competition in a diversity of systems, leading to predictable changes in functional diversity and average morphology through island ontogeny, whereas patterns of species richness appear subject to archipelago‐specific factors. 

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