Dispersal to a geographic area or colonizing a new habitat can lead to ecological opportunity, which predicts that in absent or reduced competition, lineages can diversify to exploit available resources, ultimately leading to adaptive radiation. We investigated the role of colonizing new environments with novel community contexts in Central Mexican Silversides, a putative adaptive radiation. We explored macroevolutionary dynamics of speciation and phenotypic evolution across New World Silversides in different community settings. We analyzed geometric morphometric, linear, and functional traits, three classes of morphological data rarely evaluated jointly in a single group. We found that Central Mexican Silversides, which occupy a region characterized by low species richness, and isolated freshwater habitats, experienced elevated rates of phenotypic evolution and speciation. In the absence of ecological opportunity, other lineages of Menidiinae experienced constant evolutionary rates through time and patterns consistent with non-adaptive diversification dynamics. We found that traits related to piscivory and burst-swimming have the highest rates of evolution in Central Mexican Silversides. We also show that functional traits and linear morphometrics better capture among lineage variation than body shape data. Our study shows that unique paleogeographic and ecological settings can promote adaptive radiation in clades that otherwise experience steady-state diversification dynamics.

The partitioning of global biodiversity into biogeographic regions is critical for understanding the impacts of global-scale ecological and evolutionary processes on species assemblages as well as prioritizing areas for conservation. However, the lack of globally comprehensive data on species distributions preclude fine-scale estimation of biogeographical regionalization for numerous taxa of ecological, economic, and conservation interest. Using a recently-published phylogeny and novel curated native range maps for over 10,000 species of butterflies around the world, we delineated biogeographic regions for the world’s butterflies using phylogenetic dissimilarity. We uncovered 19 distinct phylogenetically delimited regions (phyloregions) nested within 6 realms. Regional boundaries were predicted by spatial turnover in modern-day temperature and precipitation seasonality, but historical climate change also left a significant fingerprint on deeper- (realm-) level boundaries. We use a culturally and ecologically important group of insects to expand our understanding of how historical and contemporary factors drive the distribution of organismal lineages on Earth. As insects and global biodiversity more generally face unprecedented challenges from anthropogenic factors, our research provides the groundwork for prioritizing regions and taxa for conservation, especially with the goal of preserving the legacies of our biosphere’s evolutionary history.

A process-driven biogeochemistry model, Wetland Carbon Assessment Tool - DeNitrification-DeComposition model (WCAT-DNDC) was validated and applied to examine the responses of daily net ecosystem exchange (NEE), net primary productivity (NPP), ecosystem respiration (ER), methane (CH4) and nitrous oxide (N2O) emissions in the Lake Maurepas swamp forests under dry (2011), normal (2019), and wet (2021) conditions, SLR (low 0.27 m and high 0.50 m over the next 50 years), and a Mississippi River (MR) diversion with various hydrologic and salinity regimes. Model simulations were conducted at twelve Coastwide Reference Monitoring System (CRMS) sites that were classified as three habitats (throughput, relict, and degraded) inside the Lake Maurepas swamp forests.

Jawless vertebrates once dominated Paleozoic waters, but just two lineages persisted to the present day: lampreys and hagfishes. Living lampreys are a relatively small clade, with just over fifty species described, but knowledge of their evolutionary relationships has always been based on either a few mitochondrial genes or a small number of taxa. Biogeographers have noted the disjunct antitropical distribution of living lamprey families. Here we present a comprehensive phylogenomic analysis of living and fossil lampreys, sampling 36 species with phylogenomic data and 46 in total with genetic data. We present new divergence time estimates based on comprehensive nuclear data and analysis of their diversification dynamics. Our analysis indicates a central role for extreme global warming during the Late Cretaceous Cenomanian-Turonian Boundary Event as a likely cause for the antitropical distribution of living lampreys, and a notable increase in lineage diversification in northern hemisphere lampreys during the Miocene corresponding with a period of global cooling.

Reconstructing the evolutionary history of different groups of organisms provides insight into how life originated and diversified on Earth. Phylogenetic trees are commonly used to estimate this evolutionary history. Within Bayesian phylogenetics a major step in estimating a tree is in choosing an appropriate model of character evolution. While the most common character data used is molecular sequence data, morphological data remains an vital source of information. The use of morphological characters allows for the incorporation fossil taxa, and despite advances in molecular sequencing, continues to play a significant role in neontology. Moreover, it is the main data source that allows us to unite extinct and extant taxa directly under the same generating process. We therefore require suitable models of morphological character evolution, the most common being the Mk Lewis model. While it is frequently used in both palaeobiology and neontology, it is not known whether the simple Mk substitution model, or any extensions to it, provide a sufficiently good description of the process of morphological evolution. In this study we investigate the impact of different morphological models on empirical tetrapod data sets. Specifically, we compare unpartitioned Mk models with those where characters are partitioned by the number of observed states, both with and without allowing for rate variation across sites and accounting for ascertainment bias. We show that the choice of substitution model has an impact on both topology and branch lengths, highlighting the importance of model choice. Through simulations, we validate the use of the model adequacy approach, posterior predictive simulations, for choosing an appropriate model. Additionally we compare the performance of model adequacy with Bayesian model selection. We demonstrate how model selection approaches based on marginal likelihoods are not appropriate for choosing between models with partition schemes that vary in character state space (i.e., that vary in Q-matrix state size).Using posterior predictive simulations we found that current variations of the Mk model are often performing adequately in capturing the evolutionary dynamics that generated our data. We do not find any preference for a particular model extension across multiple data sets, indicating that there is no `one size fits all' when it comes to morphological data and that careful consideration should be given to choosing models of discrete character evolution. By using suitable models of character evolution, we can increase our confidence in our phylogenetic estimates, which should in turn allow us to gain more accurate insights into the evolutionary history of both extinct and extant taxa.

All foraging animals face a trade-off: how much time should they invest in exploitation of known resources versus exploration to discover new resources? For group-living central place foragers, this balance is challenging. Due to the nature of their movement patterns, exploration and exploitation are often mutually exclusive, while the availability of social information may discourage individuals from exploring. To examine these trade-offs, we GPS-tracked groups of greater spear-nosed bats (Phyllostomus hastatus) from three colonies on Isla Colón, Panamá. During the dry season, when these omnivores forage on the nectar of unpredictable balsa flowers, bats consistently travelled long distances to remote, colony-specific foraging areas, bypassing flowering trees closer to their roosts. They continued using these areas in the wet season, when feeding on a diverse, presumably ubiquitous diet, but also visited other, similarly distant foraging areas. Foraging areas were shared within, but not always between colonies. Our longitudinal dataset suggests that bats from each colony invest in long-distance commutes to socially learned shared foraging areas, bypassing other available food patches. Rather than exploring nearby resources, these bats exploit colony specific foraging locations that appear to be culturally transmitted. These results give insight into how social animals might diverge from optimal foraging.

Read Counts per geneAll read counts by inidividual and speciesSpecies abbreviations keyR script for data analyses

Read Counts per geneAll read counts by inidividual and speciesSpecies abbreviations keyR script for data analyses

Phylogenetic trees establish a historical context for the study of organismal form and function. Most phylogenetic trees are estimated using a model of evolution. For molecular data, modeling evolution is often based on biochemical observations about changes between character states. For example, there are four nucleotides, and we can make assumptions about the probability of transitions between them. By contrast, for morphological characters, we may not know a priori how many character states there are per character, as both extant sampling and the fossil record may be highly incomplete, which leads to an observer bias. For a given character, the state space may be larger than what has been observed in the sample of taxa collected by the researcher. In this case, how many evolutionary rates are needed to even describe transitions between morphological character states may not be clear, potentially leading to model misspecification. To explore the impact of this model misspecification, we simulated character data with varying numbers of character states per character. We then used the data to estimate phylogenetic trees using models of evolution with the correct number of character states and an incorrect number of character states. The results of this study indicate that this observer bias may lead to phylogenetic error, particularly in the branch lengths of trees. If the state space is wrongly assumed to be too large, then we underestimate the branch lengths, and the opposite occurs when the state space is wrongly assumed to be too small.

Coastal wetlands store carbon in their soils. Carbon is produced by emergent biomass and in-situ root growth, as well as deposited through sedimentation. Burial of aboveground carbon within soils and disruption of long-term soil carbon storage are both influenced by the fauna present in coastal wetlands. Data were used to test the hypothesis that the American Alligator (Alligator mississippiensis) offsets the losses of soil carbon as influenced by herbivores by serving in herbivore population control, thereby facilitating greater soil carbon storage when alligators are present. Data were either extracted on-line (https://serc.si.edu/coastal-carbon, accessed 11 July 2024) or through surveys conducted along the Atlantic and Gulf Coasts of the United States. R code for the analyses used is also provided.