It is time to explore the impact of length of gestation and fetal health on the human lifespan.

A recently proposed principal law of lifespan (PLOSP) proposes to extend the whole human lifespan by elongating different life stages. As the preborn stage of a human being, gestation is the foundation for the healthy development of the human body. The antagonistic pleiotropy (AP) theory of aging states that there is a trade-off between early life fitness and late-life mortality. The question is whether slower development during the gestation period would be associated with a longer lifespan. Among all living creatures, the length of the gestation period is highly positively correlated to the length of the lifespan, although such a correlation is thought to be influenced by the body sizes of different species. While examining the relationship between lifespan length and body size within the same species, dogs exhibit a negative correlation between lifespans and body sizes, while there is no such correlation among domestic cats. For humans, most adverse gestational environments shorten the period of gestation, and their impacts are long-term. While many issues remain unsolved, various developmental features have been linked to the conditions during the gestation period. Given that the length of human pregnancies can vary randomly by as long as 5 weeks, it is worth investigating whether a slow steady healthy gestation over a longer period will be related to a longer and healthier lifespan. This article discusses the potential benefits, negative impacts, and challenges of the relative elongation of the gestation period.

Multiple factors influence claw characteristics in oribatid mites (Acari).

Claws, as nature's multifaceted instruments, play fundamental roles across the animal kingdom, aiding in prey capture and enabling movement across diverse terrains. Claw features often reflect the ecologies of the respective taxa and thus can provide important insights into the different lifestyles. This study explores the claw morphology of monodactylous oribatid mites through geometric morphometrics, analyzing 559 specimens from 49 species across various ecosystems. The research identifies distinct claw characteristics associated with specific habitats, revealing a significant correlation between claw morphology and the mites' environmental adaptations. Littoral mites exhibit notably larger claws compared to terrestrial counterparts, with aquatic and semiaquatic species presenting intermediate traits. The analysis shows an inverse relationship between claw curvature and sharpness, differing from patterns observed in larger animals. A trend of increasing claw bluntness with body size in terrestrial mites echoes biomechanical constraints seen in larger species. The study also observes consistent claw shapes within oribatid superfamilies, suggesting a potential, albeit muted, phylogenetic influence alongside environmental factors. These findings reveal how ecological, evolutionary, and functional aspects influence claw morphology in oribatid mites, enhancing our knowledge of arthropod biology and potentially inspiring biomimetic advances in material science and engineering.

Correlated evolution between body size and echolocation in bats (order Chiroptera).

BACKGROUND: Body size and echolocation call frequencies are related in bats. However, it is unclear if this allometry applies to the entire clade. Differences have been suggested between nasal and oral emitting bats, as well as between some taxonomic families. Additionally, the scaling of other echolocation parameters, such as bandwidth and call duration, needs further testing. Moreover, it would be also interesting to test whether changes in body size have been coupled with changes in these echolocation parameters throughout bat evolution. Here, we test the scaling of peak frequency, bandwidth, and call duration with body mass using phylogenetically informed analyses for 314 bat species. We specifically tested whether all these scaling patterns differ between nasal and oral emitting bats. Then, we applied recently developed Bayesian statistical techniques based on large-scale simulations to test for the existence of correlated evolution between body mass and echolocation. RESULTS: Our results showed that echolocation peak frequencies, bandwidth, and duration follow significant allometric patterns in both nasal and oral emitting bats. Changes in these traits seem to have been coupled across the laryngeal echolocation bats diversification. Scaling and correlated evolution analyses revealed that body mass is more related to peak frequency and call duration than to bandwidth. We exposed two non-exclusive kinds of mechanisms to explain the link between size and each of the echolocation parameters. CONCLUSIONS: The incorporation of Bayesian statistics based on large-scale simulations could be helpful for answering macroevolutionary patterns related to the coevolution of traits in bats and other taxonomic groups.

Small skeletons show size-specific scaling: an exploration of allometry in the mammalian lumbar spine.

Studies of vertebrate bone biomechanics often focus on skeletal adaptations at upper extremes of body mass, disregarding the importance of skeletal adaptations at lower extremes. Yet mammals are ancestrally small and most modern species have masses under 5 kg, so the evolution of morphology and function at small size should be prioritized for understanding how mammals subsist. We examined allometric scaling of lumbar vertebrae in the small-bodied Philippine endemic rodents known as cloud rats, which vary in mass across two orders of magnitude (15.5 g-2700 g). External vertebral dimensions scale with isometry or positive allometry, likely relating to body size and nuances in quadrupedal posture. In contrast to most mammalian trabecular bone studies, bone volume fraction and trabecular thickness scale with positive allometry and isometry, respectively. It is physiologically impossible for these trends to continue to the upper extremes of mammalian body size, and we demonstrate a fundamental difference in trabecular bone allometry between large- and small-bodied mammals. These findings have important implications for the biomechanical capabilities of mammalian bone at small body size; for the selective pressures that govern skeletal evolution in small mammals; and for the way we define 'small' and 'large' in the context of vertebrate skeletons.

Global latitudinal gradients and the evolution of body size in dinosaurs and mammals.

Global climate patterns fundamentally shape the distribution of species and ecosystems. For example, Bergmann's rule predicts that homeothermic animals, including birds and mammals, inhabiting cooler climates are generally larger than close relatives from warmer climates. The modern world, however, lacks the comparative data needed to evaluate such macroecological rules rigorously. Here, we test for Bergmann's rule in Mesozoic dinosaurs and mammaliaforms that radiated within relatively temperate global climate regimes. We develop a phylogenetic model that accounts for biases in the fossil record and allows for variable evolutionary dispersal rates. Our analysis also includes new fossil data from the extreme high-latitude Late Cretaceous Arctic Prince Creek Formation. We find no evidence for Bergmann's rule in Mesozoic dinosaurs or mammaliaforms, the ancestors of extant homeothermic birds and mammals. When our model is applied to thousands of extant dinosaur (bird) and mammal species, we find that body size evolution remains independent of latitude. A modest temperature effect is found in extant, but not in Mesozoic, birds, suggesting that body size evolution in modern birds was influenced by Bergmann's rule during Cenozoic climatic change. Our study provides a general approach for studying macroecological rules, highlighting the fossil record's power to address longstanding ecological principles.

Disentangling physiological and physical explanations for body size-dependent thermal tolerance.

The effects of climate change are often body size dependent. One contributing factor could be size-dependent thermal tolerance (SDTT), the propensity for heat and cold tolerance to vary with body size among species and among individuals within species. SDTT is hypothesized to be caused by size differences in the temperature dependence of underlying physiological processes that operate at the cellular and organ/system level (physiological SDTT). However, temperature-dependent physiology need not change with body size for SDTT to be observed. SDTT can also arise because of physical differences that affect the relative body temperature dynamics of large and small organisms (physical SDTT). In this Commentary, I outline how physical SDTT occurs, its mechanistic differences from physiological SDTT, and how physical and physiological SDTT make different predictions about organismal responses to thermal variation. I then describe how physical SDTT can influence the outcome of thermal tolerance experiments, present an experimental framework for disentangling physical and physiological SDTT, and provide examples of tests for physiological SDTT that control for physical effects using data from Anolis lizards. Finally, I discuss how physical SDTT can affect organisms in natural environments and influence their vulnerability to anthropogenic warming. Differentiating between physiological and physical SDTT is important because it has implications for how we design and interpret thermal tolerance experiments and our fundamental understanding of thermal ecology and thermal adaptation.

Body size mediates the functional potential of soil organisms by diversity and community assembly across soil aggregates.

Body size is an important life-history trait that affects organism niche occupancy and ecological interactions. However, it is still unclear to what extent the assembly process of organisms with different body sizes affects soil biogeochemical cycling processes at the aggregate level. Here, we examined the diversity and community assembly of soil microorganisms (bacteria, fungi, and protists) and microfauna (nematodes) with varying body sizes. The microbial functional potential associated with carbon, nitrogen, phosphorus, and sulfur metabolism within three soil aggregate sizes (large macroaggregates, > 2 mm; small macroaggregates, 0.25-2 mm; and microaggregates, < 0.25 mm) were determined by metagenomics. We found that the smallest microbes (bacteria) had higher α-diversity and lower ß-diversity and were mostly structured by stochastic processes, while all larger organisms (fungi, protists, and nematodes) had lower α-diversity and were relatively more influenced by deterministic processes. Structural equation modeling indicated that the microbial functional potential associated with carbon, nitrogen, phosphorus, and sulfur metabolism was mainly influenced by the bacterial and protist diversity in microaggregates. In contrast, the microbial functional potential was primarily mediated by the assembly processes of four organism groups, especially the nematode community in macroaggregates. This study reveals the important roles of soil organisms with different body sizes in the functional potential related to nutrient cycling, and provides new insights into the ecological processes structuring the diversity and community assembly of organisms of different body sizes at the soil aggregate level, with implications for soil nutrient cycling dynamics.

Discontinuous, biphasic, ontogenetic shifts in the metabolic allometry of aquatic animals?

Several investigations in recent years have reported patterns of discontinuous, biphasic, loglinear variation in the metabolic allometry of aquatic animals. These putative shifts in pattern of allometry have been attributed to changes in the primary site for gas exchange from cutaneous to branchial as animals undergo ontogenetic changes in size, shape, and surface area. Because of the important implications of the earlier research with regard to both physiology and evolution, I re-examined data that purportedly support claims of discontinuous, biphasic allometry in oxygen consumption versus body size of American eels (Anguilla rostrata) and spiny lobsters (Sagmariasus verreauxi). I used ANCOVA to fit three different statistical models to each set of logarithmic transformations and then assessed the fits by Akaike's Information Criterion. The observations for both species were described better by a single straight line fitted to the full distribution than by a biphasic model. Eels, lobsters, and other aquatic animals undergo changes in shape and surface area as they grow, but such changes are not necessarily accompanied by changes in the pattern of metabolic allometry.

A Taxonomic Revision of the South American Trilobite Cockroaches of Parahormetica Brunner von Wattenwyl 1865 (Blattodea: Blaberidae), with Description of Parahormetica museunacional sp. nov. from the Atlantic Forest.

The taxonomically intricate genus of trilobite cockroaches, Parahormetica Brunner von Wattenwyl, 1865, is revised based on a comparative morphological analysis. The goals of this study are to review the nomenclature, propose hypotheses about specific delimitation, and provide diagnoses to allow identification of the taxonomic units in the genus. Based on the revised status of Parahormetica, we transferred Parahormetica hylaeceps Miranda-Ribeiro, 1936, and Parahormetica punctata Saussure, 1873, to the genus Bionoblatta Rehn, 1940. Therefore, the genus includes now four species of giant cockroaches which are predominantly distributed on the Atlantic Forest: Parahormetica bilobata (Saussure, 1864), Parahormetica cicatricosa Saussure, 1869, Parahormetica monticollis (Burmeister, 1838), and Parahormetica museunacional sp. nov. (holotype male deposited in DZUP: Brazil, Paraná). Diagnoses, key, distribution maps, images of living, non-type, and type specimens are made available. Our results make clear that the status and limits among Brachycolini genera pending a full revision.

Genetic mechanism of body size variation in groupers: Insights from phylotranscriptomics.

Animal body size variation is of particular interest in evolutionary biology, but the genetic basis remains largely unknown. Previous studies have shown the presence of two parallel evolutionary genetic clusters within the fish genus Epinephelus with evident divergence in body size, providing an excellent opportunity to investigate the genetic basis of body size variation in vertebrates. Herein, we performed phylotranscriptomic analysis and reconstructed the phylogeny of 13 epinephelids originating from the South China Sea. Two genetic clades with an estimated divergence time of approximately 15.4 million years ago were correlated with large and small body size, respectively. A total of 180 rapidly evolving genes and two positively selected genes were identified between the two groups. Functional enrichment analyses of these candidate genes revealed distinct enrichment categories between the two groups. These pathways and genes may play important roles in body size variation in groupers through complex regulatory networks. Based on our results, we speculate that the ancestors of the two divergent groups of groupers may have adapted to different environments through habitat selection, leading to genetic variations in metabolic patterns, organ development, and lifespan, resulting in body size divergence between the two locally adapted populations. These findings provide important insights into the genetic mechanisms underlying body size variation in groupers and species differentiation.

Revisiting niche divergence hypothesis in sexually dimorphic birds: Is diet overlap correlated with sexual size dimorphism?

The evolution of sexual size dimorphism (SSD) is a long-standing topic in evolutionary biology, but there is little agreement on the extent to which SSD is driven by the different selective forces. While sexual selection and fecundity selection have traditionally been proposed as the two leading hypotheses, SSD may also result from natural selection through mechanisms such as sexual niche divergence, which might have reduced resource competition between sexes. Here, we revisited the niche divergence hypothesis by testing the relationship between the sexual overlap in diet and SSD of 56 bird species using phylogenetic comparative analyses. We then assessed how SSD variation relates to the three main hypotheses: sexual selection, fecundity selection, and sexual niche divergence using phylogenetic generalized least squares (PGLS). Then, we compared sexual selection, fecundity selection and niche divergence selection as SSD drivers through phylogenetic confirmatory path analyses to disentangle the possible causal evolutionary relationships between SSD and the three hypotheses. Phylogenetic generalized least squares showed that SSD was negatively correlated with diet overlap, that is, the greater the difference in body size between males and females, the less diet overlap. As predicted by sexual selection theory, the difference in body size between sexes was higher in polygynous species. Confirmatory phylogenetic path analyses suggested that the most likely evolutionary path might include the mating system as a main driver in SSD and niche divergence as a result of SSD. We found no evidence of a role of fecundity selection in the evolution of female-biased SSD. Our study provides evidence that sexual selection has likely been the main cause of SSD and that dietary divergence is likely an indirect effect of SSD.

Heat and desiccation tolerances predict bee abundance under climate change.

Climate change could pose an urgent threat to pollinators, with critical ecological and economic consequences. However, for most insect pollinator species, we lack the long-term data and mechanistic evidence that are necessary to identify climate-driven declines and predict future trends. Here we document 16 years of abundance patterns for a hyper-diverse bee assemblage1 in a warming and drying region2, link bee declines with experimentally determined heat and desiccation tolerances, and use climate sensitivity models to project bee communities into the future. Aridity strongly predicted bee abundance for 71% of 665 bee populations (species × ecosystem combinations). Bee taxa that best tolerated heat and desiccation increased the most over time. Models forecasted declines for 46% of species and predicted more homogeneous communities dominated by drought-tolerant taxa, even while total bee abundance may remain unchanged. Such community reordering could reduce pollination services, because diverse bee assemblages typically maximize pollination for plant communities3. Larger-bodied bees also dominated under intermediate to high aridity, identifying body size as a valuable trait for understanding how climate-driven shifts in bee communities influence pollination4. We provide evidence that climate change directly threatens bee diversity, indicating that bee conservation efforts should account for the stress of aridity on bee physiology.

A new Chinese Cyclogethes pollen beetle, with an updated key to species of the genus and notes on its phylogenetic positioning (Coleoptera: Nitidulidae: Meligethinae).

A peculiar new species of the genus Cyclogethes Kirejtshuk, 1979, C. tibialis sp. nov., is described from Southwestern China (Yunnan). The new species appears to be morphologically rather isolated from the other known members of this essentially Oriental genus (including half a dozen species from Northern Indian subcontinent, Northern Indochina, and Southwestern China). However, it could be more closely related to C. abnormis Kirejtshuk, 1979 from Northern India, Indochina, and Southwestern China, and to C. aldridgei Kirejtshuk, 1980 from Northern India and Nepal, from which it is easily distinguished by the more elongate body shape, and by the markedly sinuate hind tibiae in both sexes (a very unusual character state in Meligethinae, where only males of some species exhibit sexual secondary characters in the tibial shape). The new species also differs from other known taxa of the genus by the shape of the male and female genitalia. The larval hostplants of members of Cyclogethes are thus far unknown, although some clues, also involving the new species described herein, may suggest a relationship with small trees or shrubs of the family Asteraceae. Preliminary and incomplete molecular data on a studied member of the genus (C. abnormis) seems to not disagree with a phylogenetic positioning of Cyclogethes in a clade including the African genera Tarchonanthogethes Audisio & Cline, 2009, its allied Afrotropical taxa, and the Palaearctic genera Meligethes Stephens, 1830 and Brassicogethes Audisio & Cline, 2009. The article includes an updated identification key for all six known species of this genus and an updated map of their known geographic distribution.

Review of the genus Antoniejanse Kemal & Koak, 2005 (Lepidoptera, Gelechiidae, Litini), with description of four new species.

The southern African genus Antoniejanse Kemal & Koak, 2005 is revised. Seven species are recognized here as valid, of which four species are described as new for science from South Africa (A. varii sp. nov. and A. tenebrosa sp. nov.) and Namibia (A. minima sp. nov. and A. mediopunctata sp. nov.). One new combination is proposed: Antoniejanse sagittata (Bidzilya, 2019) comb. nov. (ex Paratelphusa). All species of Antoniejanse are re-diagnosed. Wing patterns, as well as male and female genitalia are depicted. An identification key to all species of the genus is provided and the checklist of the genus is updated.

New teratological cases in cuckoo wasps, with synonymization of Oligogaster Soliman & Kimsey (Hymenoptera, Chrysididae).

Aberrations involving the metasoma in Hymenoptera are well-documented, with one notable teratological case being the fusion of metasomal terga, named symphysomery. This aberration, characterized by the fusion of the second and third terga, has been observed in various species groups of Hedychridium, spanning from Southern Africa to Central Asia. Similar aberrations were noted in Prochridium Linsenmaier from Mongolia and Anachrysis Krombein from Southern Africa. The monotypic genus Oligogaster Soliman & Kimsey is distinguished by two visible metasomal terga. However, the sole specimen of Oligogaster kimseyae Soliman, the type species of the genus, is here considered an aberrant specimen affected by symphysomery, exhibiting the fusion of the second and third metasomal terga. Consequently, Oligogaster Soliman & Kimsey is here synonymized with Hedychridium Abeille de Perrin.

Contributions to Odontogryllini (Orthoptera: Gryllidae: Landrevinae) with comments on its taxonomic status and description of a new species of Xulavuna de Mello & Campos, 2014.

Odontogryllini is a tribe of ground-dwelling crickets exclusive to America. After several taxonomic rearrangements, this tribe has five genera and 23 species now placed in the subfamily Landrevinae. These crickets have dorsoventrally depressed bodies and are moderately to densely covered with bristles. The males may bear tegminal, metanotal, or tergal glands. In this contribution, we discuss the taxonomic status and the morphological features of Odontogryllini and the other two tribes of Landrevinae: Landrevini and Prolandrevini. The presence of dorsal spines between the outer spurs of the hind tibia distinguishes Odontogryllini from Prolandrevini, and the straight or slightly arcuate but never S-shaped stridulum from Landrevini. We also propose the enlarged and plate-like rami as a diagnostic characteristic to distinguish Odontogryllini from Landrevini. Additionally, we describe a new species of the genus Xulavuna de Mello & Campos from the Brazilian Amazon Rainforest, named Xulavuna krenakore sp. nov..

Description of a new species of the genus Woznessenskia from Xizang, China (Orthoptera: Gryllacrididae).

The gryllacridid genus Woznessenskia Gorochov, 2002 comprises 13 extant species from Asia, with 8 species reported from China and 5 species reported from Vietnam. A new species from Xizang, China, Woznessenskia lianhua sp. nov., is reported in this paper.

Notes on the genus Homogryllacris Liu, 2007 (Orthoptera: Gryllacrididae) with description of one new species from China.

This paper deals with five species of the genus Homogryllacris Liu, 2007 from China, including one new species, i.e. Homogryllacris nigromacula sp. nov. Morphological illustrations of most species and habitus of the new species are provided. Moreover, one geographical population of Homogryllacris yunnana Shi, Guo & Bian, 2012 and intraspecific variation of Homogryllacris platycis Liu & Bian, 2021 are discussed and illustrated. All specimens examined are deposited in the Museum of Hebei University.

Taxonomic notes on the genus Heliophanus C.L. Koch, 1833, with description of three additional genera (Araneae: Salticidae: Chrysillini).

Intrageneric taxonomy of genus Heliophanus C.L. Koch, 1833 is revised. Two subgenera are elevated to the generic ranks: Helafricanus Wesoowska, 1986 (type species Heliophanus patellaris Simon, 1901) and Heliocapensis Wesoowska, 1986 (type species Heliophanus peckhami Simon, 1902). Generic name Trapezocephalus Berland & Millot, 1941 is removed from synonyms of Heliophanus and reinstalled as valid genus (type species Heliophanus cassinicola Simon, 1909 = Trapezocephalus aeluriliformis Berland & Millot, 1941). Genera Helafricanus, Heliocapensis, Heliophanus s. str. and Trapezocephalus are redefined, and their updated diagnoses and compositions are given. Seventy-three new combinations are proposed from Heliophanus s. lato. Five specific names are synonymized: Heliophanus thaleri Wesoowska, 2009 with Heliophanus termitophagus Wesoowska & Haddad, 2002, Heliophanus patagiatus albolineatus Kulczyski, 1901 with Heliophanus patagiatus Thorell, 1875, Heliophanus montanus Wesoowska, 2006 with Heliophanus capicola Simon, 1901 (and transferred to Trapezocephalus), Heliophanus berlandi Lawrence, 1937 with Baryphas ahenus Simon, 1902, and Astia hariola L. Koch,1879 with Heliophanus maculatus Karsch,1878, for the latter species Astia maculata (Karsch,1878) comb. nov. is proposed. Heliophanus japonicus Kishida, 1910 is recognized as nomen dubium.

Heterlimnius luyashanensis sp. n. and Zaitzevia triangularis sp. n. from Shanxi Province, China (Coleoptera: Elmidae).

Two new species, Heterlimnius luyashanensis sp. n. and Zaitzevia triangularis sp. n. are described from Shanxi Province, China. The genus Heterlimnius Hinton, 1935 and Zaitzevia Champion, 1923 are reported from Shanxi Province for the first time. Heterlimnius luyashanensis sp. n. belonging to the Heterlimnius trachys species group has the following characteristics: 1. anterior margin of pronotum strongly produced anteriad; 2. median longitudinal sulcus of pronotum extends from basal 0.3 to 0.8. Zaitzevia triangularis sp. n. has a larger body size and a triangular apex of penis.