American NaturalistPub Date : 2025-03-01Epub Date: 2025-01-17DOI: 10.1086/733931
Aintzane Santaquiteria, Elizabeth Christina Miller, Ulises Rosas-Puchuri, Carmen Del R Pedraza-Marrón, Emily M Troyer, Mark W Westneat, Giorgio Carnevale, Dahiana Arcila, Ricardo Betancur-R
{"title":"Colonization Dynamics Explain the Decoupling of Species Richness and Morphological Disparity in Syngnatharian Fishes across Oceans.","authors":"Aintzane Santaquiteria, Elizabeth Christina Miller, Ulises Rosas-Puchuri, Carmen Del R Pedraza-Marrón, Emily M Troyer, Mark W Westneat, Giorgio Carnevale, Dahiana Arcila, Ricardo Betancur-R","doi":"10.1086/733931","DOIUrl":"10.1086/733931","url":null,"abstract":"<p><p>AbstractA clear longitudinal gradient in species richness across oceans is observed in extant marine fishes, with the Indo-Pacific exhibiting the greatest diversity. Three non-mutually-exclusive evolutionary hypotheses have been proposed to explain this diversity gradient: time for speciation, center of accumulation, and in situ diversification rates. Using the morphologically disparate syngnatharians (seahorses, dragonets, goatfishes, and relatives) as a study system, we tested these hypotheses and additionally assessed whether patterns of morphological diversity are congruent with species richness patterns. We used well-sampled phylogenies and a suite of phylogenetic comparative methods (including a novel phylogenetically corrected Kruskal-Wallis test) that account for various sources of uncertainty to estimate rates of lineage diversification and morphological disparity within all three major oceanic realms (Indo-Pacific, Atlantic, and eastern Pacific), as well as within the Indo-Pacific region. We find similar lineage diversification rates across regions, indicating that increased syngnatharian diversity in the Indo-Pacific is due to earlier colonizations from the Tethys Sea followed by in situ speciation and more frequent colonizations during the Miocene coinciding with the formation of coral reefs. These results support both time for speciation and center of accumulation hypotheses. Unlike species richness unevenness, shape disparity and evolutionary rates are similar across oceans because of the early origin of major body plans and their subsequent spread via colonization rather than in situ evolution. Our results illustrate how species richness patterns became decoupled from morphological disparity patterns during the formation of a major biodiversity hot spot.</p>","PeriodicalId":50800,"journal":{"name":"American Naturalist","volume":"205 3","pages":"E80-E99"},"PeriodicalIF":2.4,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143450865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
American NaturalistPub Date : 2025-03-01Epub Date: 2025-01-17DOI: 10.1086/733197
Keila A Stark, Tom Clegg, Joey R Bernhardt, Tess N Grainger, Christopher P Kempes, Van Savage, Mary I O'Connor, Samraat Pawar
{"title":"Toward a More Dynamic Metabolic Theory of Ecology to Predict Climate Change Effects on Biological Systems.","authors":"Keila A Stark, Tom Clegg, Joey R Bernhardt, Tess N Grainger, Christopher P Kempes, Van Savage, Mary I O'Connor, Samraat Pawar","doi":"10.1086/733197","DOIUrl":"10.1086/733197","url":null,"abstract":"<p><p>AbstractThe metabolic theory of ecology (MTE) aims to link biophysical constraints on individual metabolic rates to the emergence of patterns at the population and ecosystem scales. Because MTE links temperature's kinetic effects on individual metabolism to ecological processes at higher levels of organization, it holds great potential to mechanistically predict how complex ecological systems respond to warming and increased temperature fluctuations under climate change. To scale up from individuals to ecosystems, applications of classical MTE implicitly assume that focusing on steady-state dynamics and averaging temperature responses across individuals and populations adequately capture the dominant attributes of biological systems. However, in the context of climate change, frequent perturbations from steady state and rapid changes in thermal performance curves via plasticity and evolution are almost guaranteed. Here, we explain how some of the assumptions made when applying MTE's simplest canonical expression can lead to blind spots in understanding how temperature change affects biological systems and how this presents an opportunity for formal expansion of the theory. We review existing advances in this direction and provide a decision tree for identifying when dynamic modifications to classical MTE are needed for certain research questions. We conclude with empirical and theoretical challenges to be addressed in a more dynamic MTE for understanding biological change in an increasingly uncertain world.</p>","PeriodicalId":50800,"journal":{"name":"American Naturalist","volume":"205 3","pages":"285-305"},"PeriodicalIF":2.4,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143450878","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
American NaturalistPub Date : 2025-03-01Epub Date: 2025-01-24DOI: 10.1086/733792
Douglas G Barron, Hubert Schwabl, Patrick A Carter, Daniel T Baldassarre, Willow R Lindsay, Jordan Karubian, Michael S Webster
{"title":"Females with Attractive Mates Gain Environmental Benefits That Increase Lifetime and Multigenerational Fitness.","authors":"Douglas G Barron, Hubert Schwabl, Patrick A Carter, Daniel T Baldassarre, Willow R Lindsay, Jordan Karubian, Michael S Webster","doi":"10.1086/733792","DOIUrl":"10.1086/733792","url":null,"abstract":"<p><p>AbstractResolving the degree to which environmental (direct) versus genetic (indirect) benefits shape female mate choice is a long-standing challenge, particularly for socially monogamous species where male environmental and genetic contributions are difficult to disentangle. This study combines long-term population monitoring with quantitative genetic analyses in a socially monogamous but sexually promiscuous Australian songbird to demonstrate that female mating preferences are driven by nongenetic environmental benefits that increase the fitness of both the female and her offspring. Male Red-backed Fairywrens (<i>Malurus melanocephalus</i>) flexibly breed in either ornamented or unornamented plumage, and females consistently prefer ornamented males. Females paired with ornamented males bred earlier and allocated more to current reproduction yet experienced higher survival and lifetime fitness. Furthermore, these females produced more grand-offspring because their early-born sons were more likely to be ornamented and to breed successfully than the later-born sons of females with unornamented partners. Quantitative genetic models showed lifetime fitness was best explained by parental environment rather than genetic effects. Mating preferences in this system are maintained by a combination of primary environmental benefits that increase the lifetime fitness of choosy females and secondary environmental benefits that increase the multigenerational fitness of those females through enhanced offspring quality and performance.</p>","PeriodicalId":50800,"journal":{"name":"American Naturalist","volume":"205 3","pages":"265-279"},"PeriodicalIF":2.4,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143450868","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
American NaturalistPub Date : 2025-03-01Epub Date: 2025-01-17DOI: 10.1086/733789
Rachel Germain, Sebastian J Schreiber
{"title":"Demystifying Fundamental Theories in Ecology.","authors":"Rachel Germain, Sebastian J Schreiber","doi":"10.1086/733789","DOIUrl":"10.1086/733789","url":null,"abstract":"<p><p>AbstractAs scientists, our collective goal is to make scientific progress in the pursuit of an absolute truth about the nature of the universe, through a feedback loop of observation, theory, and experimentation. What if a major limit to progress is not the science itself but rather in how broadly scientific ideas can be understood? In this introduction to a special feature, we highlight four articles, each tasked with demystifying a key theory in ecology for a general audience, with a special focus on aspects of each theory that have been misunderstood, misapplied, or underappreciated in some important way. These four theories are metabolic theory, competition theory based on consumer-resource models, mechanisms of coexistence in fluctuating environments, and metapopulation dynamics. We point out key ways in which each article applied best practices of accessible communication as well as challenges that might arise (and potential solutions for journals and authors) when attempting to publish articles with a deeper emphasis on explanation of fundamentals than a traditional article might provide.</p>","PeriodicalId":50800,"journal":{"name":"American Naturalist","volume":"205 3","pages":"280-284"},"PeriodicalIF":2.4,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143450866","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
American NaturalistPub Date : 2025-03-01Epub Date: 2025-01-22DOI: 10.1086/733382
Chhaya M Werner, Lauren M Hallett, Lauren G Shoemaker
{"title":"Fluctuation-Dependent Coexistence of Stage-Structured Species.","authors":"Chhaya M Werner, Lauren M Hallett, Lauren G Shoemaker","doi":"10.1086/733382","DOIUrl":"10.1086/733382","url":null,"abstract":"<p><p>AbstractModern coexistence theory is a dominant framework for understanding how environmental fluctuations promote species coexistence. However, assessing fluctuation-dependent mechanisms of coexistence in empirical systems-in which species have diverse life histories and environment-competition relationships-has remained challenging for many ecologists. To help empiricists and theoreticians alike build intuition for the role of fluctuation-dependent mechanisms across systems and environments, we explore how two stage-structured life histories-perennial and seedbanking annuals-differ in competition with a nonseedbanking annual across three environmental scenarios. Our scenarios delineate how species partition resources within and among years and whether competition is most intense during favorable or unfavorable periods. We use this work to link differences in vital rates and interaction strengths to patterns and mechanisms of coexistence. Fluctuation-dependent mechanisms of coexistence can be equally important for perennial species with an adult \"storage\" stage as for seedbanking annuals. However, coexistence outcomes differentiate between these two stage-structured strategies based on whether they experience stronger or weaker competition in favorable environments. This work sets the stage for applying coexistence theory and fluctuation-dependent partitioning frameworks to perennial and mixed stage-structure communities, facilitating understanding of how environmental variation drives species dynamics across a broader range of systems.</p>","PeriodicalId":50800,"journal":{"name":"American Naturalist","volume":"205 3","pages":"327-341"},"PeriodicalIF":2.4,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143450869","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
American NaturalistPub Date : 2025-02-01Epub Date: 2024-12-13DOI: 10.1086/733224
Bethany L F Stevens, Kristen Howard, Laura M Bogar, Holly V Moeller
{"title":"Environmental Fluctuations Promote Host Reward Strategies That Maintain Partner Diversity in Multispecies Mutualisms.","authors":"Bethany L F Stevens, Kristen Howard, Laura M Bogar, Holly V Moeller","doi":"10.1086/733224","DOIUrl":"10.1086/733224","url":null,"abstract":"<p><p>AbstractIn multispecies mutualisms, hosts might be expected to reward only the highest-quality partner in order to maximize benefits and prevent the proliferation of cheaters. In a fluctuating environment, however, partner quality is likely to vary over time, and the maintenance of low-quality partners has been shown to be beneficial in some environmental regimes. Here, we present a model of a simple tree-fungal mutualism with two distinct environmental conditions and a host that can employ reward strategies with varying degrees of preference for higher-quality fungi. We find that in many environmental regimes, the most successful strategy for the host is one that actively maintains equal densities of the two fungal partners, in spite of their immediate differences in quality. This conservative bet-hedging strategy leads to reduced variance in the tree's carbon resources and high resilience to environmental perturbation. An alternative reward strategy, which supports only the highest-quality partner at a time, is most successful under some conditions when fluctuations in the environment are infrequent. Longer periods of environmental stasis thus increase the risk to the tree of losing fungal partner diversity. This theoretical work identifies a mechanism by which biodiversity may be actively maintained in multispecies mutualisms but that may be disrupted as environmental conditions change.</p>","PeriodicalId":50800,"journal":{"name":"American Naturalist","volume":"205 2","pages":"137-148"},"PeriodicalIF":2.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143366687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
American NaturalistPub Date : 2025-02-01Epub Date: 2024-12-12DOI: 10.1086/733415
Carlos A Serván, José A Capitán, Zachary R Miller, Stefano Allesina
{"title":"Effects of Phylogeny on Coexistence in Model Communities.","authors":"Carlos A Serván, José A Capitán, Zachary R Miller, Stefano Allesina","doi":"10.1086/733415","DOIUrl":"10.1086/733415","url":null,"abstract":"<p><p>AbstractSpecies' interactions are shaped by their traits. Thus, we expect traits-in particular, trait (dis)similarity-to play a central role in determining whether a particular set of species coexists. Traits are, in turn, the outcome of an eco-evolutionary process summarized by a phylogenetic tree. Therefore, the phylogenetic tree associated with a set of species should carry information about the dynamics and assembly properties of the community. Many studies have highlighted the potentially complex ways in which this phylogenetic information is translated into species' ecological properties. However, much less emphasis has been placed on developing clear, quantitative expectations for community properties under a particular hypothesis. To address this gap, we couple a simple model of trait evolution on a phylogenetic tree with Lotka-Volterra community dynamics. This allows us to derive properties of a community of coexisting species as a function of the number of traits, tree topology, and the size of the species pool. Our analysis highlights how phylogenies, through traits, affect the coexistence of a set of species. Together, these results provide much-needed baseline expectations for the ways in which evolutionary history, summarized by phylogeny, is reflected in the size and structure of ecological communities.</p>","PeriodicalId":50800,"journal":{"name":"American Naturalist","volume":"205 2","pages":"E34-E48"},"PeriodicalIF":2.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143366684","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
American NaturalistPub Date : 2025-02-01Epub Date: 2024-12-18DOI: 10.1086/733208
Vanya G Rohwer, Jennifer L Houtz, Maren N Vitousek, Robyn L Bailey, Eliot T Miller
{"title":"The Evolution of Using Shed Snake Skin in Bird Nests.","authors":"Vanya G Rohwer, Jennifer L Houtz, Maren N Vitousek, Robyn L Bailey, Eliot T Miller","doi":"10.1086/733208","DOIUrl":"10.1086/733208","url":null,"abstract":"<p><p>AbstractMany species of birds use shed snake skin in nest construction, but this behavior remains poorly understood. Ecological context is likely key for understanding how this unusual, but widespread, behavior evolved. We use comparative and experimental approaches to suggest that the evolution of this behavior is mediated by nest morphology and predator communities. First, we reviewed the literature and found that 78 species from 22 families have been reported to use shed snake skin in nest construction. All but one of these species are passerines and, using comparative analyses, we show that this behavior is disproportionately observed in cavity-nesting species. Second, we examined a subsample of North American species, all of which are reported to use snake skin in nest construction, to see whether the proportion of nests with snake skin differs between cavity- and open cup-nesting species. This analysis suggested that the proportion of nests with snake skin is roughly 6.5 times higher in cavity- than in open cup-nesting species. Finally, we used a series of experiments and comparisons to test four hypotheses whereby snake skin could award fitness benefits (nest predation, nest microbiotas, nest ectoparasites, social signaling) and found support for the predation hypothesis. Snake skin reduced nest predation in cavity, but not open cup, nests. These unequal fitness benefits highlight different ecological conditions between nest morphologies and likely explains why, across species, cavity-nesting birds show this behavior more frequently than open cup-nesting birds.</p>","PeriodicalId":50800,"journal":{"name":"American Naturalist","volume":"205 2","pages":"170-183"},"PeriodicalIF":2.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143366754","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
American NaturalistPub Date : 2025-02-01Epub Date: 2024-12-16DOI: 10.1086/733414
Michael Blazanin, Jeremy Moore, Sydney Olsen, Michael Travisano
{"title":"Fight Not Flight: Parasites Drive the Bacterial Evolution of Resistance, Not Escape.","authors":"Michael Blazanin, Jeremy Moore, Sydney Olsen, Michael Travisano","doi":"10.1086/733414","DOIUrl":"10.1086/733414","url":null,"abstract":"<p><p>AbstractIn the face of ubiquitous threats from parasites, hosts can evolve strategies to resist infection or to altogether avoid parasitism, for instance by avoiding behavior that could expose them to parasites or by dispersing away from local parasite threats. At the microbial scale, bacteria frequently encounter viral parasites, bacteriophages. While bacteria are known to utilize a number of strategies to resist infection by phages and can have the capacity to avoid moving toward phage-infected cells, it is unknown whether bacteria can evolve dispersal to escape from phages. To answer this question, we combined experimental evolution and mathematical modeling. Experimental evolution of the bacterium <i>Pseudomonas fluorescens</i> in environments with differing spatial distributions of the phage Phi2 revealed that the host bacteria evolved resistance depending on parasite distribution but did not evolve dispersal to escape parasite infection. Simulations using parameterized mathematical models of bacterial growth and swimming motility showed that this is a general finding: while increased dispersal is adaptive in the absence of parasites, in the presence of parasites that fitness benefit disappears and resistance becomes adaptive, regardless of the spatial distribution of parasites. Together, these experiments suggest that parasites should rarely, if ever, drive the evolution of bacterial escape via dispersal.</p>","PeriodicalId":50800,"journal":{"name":"American Naturalist","volume":"205 2","pages":"125-136"},"PeriodicalIF":2.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143366694","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
American NaturalistPub Date : 2025-02-01Epub Date: 2024-12-04DOI: 10.1086/733457
Xiaoyan Long, Tamas Székely, Jan Komdeur, Franz J Weissing
{"title":"A Life History Perspective on the Evolutionary Interplay of Sex Ratios and Parental Sex Roles.","authors":"Xiaoyan Long, Tamas Székely, Jan Komdeur, Franz J Weissing","doi":"10.1086/733457","DOIUrl":"10.1086/733457","url":null,"abstract":"<p><p>AbstractThe parental roles of males and females differ remarkably across the tree of life, and several studies suggest that parental sex roles are associated with biased sex ratios. However, there is considerable debate on the causal relationship between sex roles and sex ratios and on the relative importance of the operational sex ratio (OSR), the adult sex ratio (ASR), and the maturation sex ratio (MSR). Here, we use individual-based evolutionary simulations to investigate the joint evolution of sex-specific parental behavior and the various sex ratios in several life history scenarios. We show that typically, but not always, the sex with lower mortality or faster maturity tends to provide most of the care. The association of parental sex roles with the various sex ratios is more intricate. At equilibrium, the OSR is typically biased toward the less caring sex, but the direction and strength of OSR biases may change considerably during evolution. When the MSR or ASR is biased, a broad spectrum of parental care patterns can evolve, although the overrepresented sex generally does most of the caring. We conclude that none of the sex ratios is a driver of parental sex roles; they rather coevolve with care biases in a subtle manner.</p>","PeriodicalId":50800,"journal":{"name":"American Naturalist","volume":"205 2","pages":"E49-E65"},"PeriodicalIF":2.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143366680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}