Diversity Of Reproductive Strategies Research Articles

Filling latitudinal gaps in Tachycineta swallows: reproductive strategies in a South American species

ABSTRACT Chilean swallows (Tachycineta leucopyga) are the southernmost swallows in the Tachycineta genus, breeding from central Chile to southern Chile and Argentina. Studies focused on a population breeding at 54°S in Tierra del Fuego, revealed differences in life-history traits compared to their Northern Hemisphere congeners, such as smaller clutch size, and greater male nest attendance during the incubation period. To assess the consistency of these patterns for the species, we studied breeding biology and parental care of Chilean swallows in Northwestern Argentine Patagonia (41°S). If austral population breeding traits reflect species traits, we predict smaller clutch size, higher female reproductive investment, and similar nest attendance by both sexes during incubation compared to Tachycineta species breeding at similar Northern Hemisphere latitudes. We also anticipate negative correlation between clutch size, egg size, and breeding success with laying date, as observed in Tachycineta species, including Chilean swallows. Surprisingly, clutch and egg sizes did not differ between northern and southern Patagonian populations. We did not find evidence of a negative relationship between clutch or egg size and laying date. Male nest attendance during incubation was variable and low, but their nestlings feeding rates equalled those of females. These findings suggest that Chilean swallows adopt diverse reproductive strategies across regions. This may help this species adapt to different environments and climates, ranging from the shorter breeding seasons and lower summer mean temperatures of Tierra del Fuego to the longer breeding seasons and higher seasonal and daily thermal amplitudes in continental north Andean Patagonia.

Quantifying maternal investment in mammals using allometry.

Maternal investment influences the survival and reproduction of both mothers and their progeny and plays a crucial role in understanding individuals' life-history and population ecology. To reveal the complex mechanisms associated with reproduction and investment, it is necessary to examine variations in maternal investment across species. Comparisons across species call for a standardised method to quantify maternal investment, which remained to be developed. This paper addresses this limitation by introducing the maternal investment metric - MI -for mammalian species, established through the allometric scaling of the litter mass at weaning age by the adult mass and investment duration (i.e. gestation + lactation duration) of a species. Using a database encompassing hundreds of mammalian species, we show that the metric is not highly sensitive to the regression method used to fit the allometric relationship or to the proxy used for adult body mass. The comparison of the maternal investment metric between mammalian subclasses and orders reveals strong differences across taxa. For example, our metric confirms that Eutheria have a higher maternal investment than Metatheria. We discuss how further research could use the maternal investment metric as a valuable tool to understand variation in reproductive strategies.

Invasive Californian death caps develop mushrooms unisexually and bisexually

Canonical sexual reproduction among basidiomycete fungi involves the fusion of two haploid individuals of different mating types, resulting in a heterokaryotic mycelial body made up of genetically different nuclei. Using population genomics data and experiments, we discover mushrooms of the invasive and deadly Amanita phalloides can also be homokaryotic; evidence of sexual reproduction by single, unmated individuals. In California, genotypes of homokaryotic mushrooms are also found in heterokaryotic mushrooms, implying nuclei of homokaryotic mycelia are also involved in outcrossing. We find death cap mating is controlled by a single mating type locus, but the development of homokaryotic mushrooms appears to bypass mating type gene control. Ultimately, sporulation is enabled by nuclei able to reproduce alone as well as with others, and nuclei competent for both unisexuality and bisexuality have persisted in invaded habitats for at least 17 but potentially as long as 30 years. The diverse reproductive strategies of invasive death caps are likely facilitating its rapid spread, suggesting a profound similarity between plant, animal and fungal invasions.

O-081 A 10-year follow-up of reproductive outcomes in women returning after elective oocyte cryopreservation

Abstract Study question What are the reproductive treatment outcomes in women who underwent elective oocyte cryopreservation (EOC) returning to our clinic with a desire for a child? Summary answer Whether to warm oocytes or to first use fresh oocytes for ART depends on age upon returning, but both strategies resulted in favourable reproductive outcomes. What is known already Most affluent countries have observed a trend towards postponement of childbearing, and EOC is increasingly used in an attempt to extend the reproductive lifespan and mitigate age-related fertility decline. Although most follow-up studies after EOC have focused on women who requested oocyte warming, a substantial proportion of women who do not conceive naturally eventually embark for a fertility treatment without using their cryopreserved oocytes. Reports on reproductive outcomes in past EOC users are scarce, and the lack of reproductive treatment algorithms in this group of women hampers efficiency of clinical practice. Study design, size, duration This retrospective observational single-center study includes 843 women who had elective oocyte vitrification for non-medical reasons between 2009 and 2019, and describes the outcomes of the diverse reproductive treatment strategies that were performed in these women when they returned to the same clinic because of a desire for pregnancy until May 2022. Participants/materials, setting, methods Patient characteristics and data of ovarian stimulation of EOC cycles were analyzed, as well as data related to ovarian stimulation and laboratory data of ART in women who pursued fertility treatment with and/or without using their cryopreserved oocytes. The primary outcome was the live birth rate (LBR) per patient after oocyte warming and after ART using fresh oocytes. Secondary outcomes were laboratory outcomes and LBR per embryo transfer. Main results and the role of chance A total of 1353 EOC cycles (1.6 ± 0.9 per patient) were performed. Mean age was 36.5 ± 2.8 years. At the time of EOC 174 (20,6%) women had a partner. On average, 13.7 ± 9.2 mature oocytes were cryopreserved. After 39.9 ± 23.4 months, 231 (27.4%) women returned to the clinic. Upon returning, mean age was 40.4 ± 3.1 years, mean AMH 2.3 ± 2.0 ng/mL, and 150/231 (64,9%) patients had a partner. As a primary approach, 110/231 (47.6 %) past EOC women embarked on oocyte warming, 50/231 (21.6%) had intrauterine insemination, and 71/231 (30.7%) had ART using fresh oocytes. Cumulative LBR (CLBR) was 45.9 % (106/231) and miscarriage rate (MR) was 30.7% (51/166) in the entire cohort. A subset of 90/231 (39.0%) patients exclusively had oocyte warming, at 41.6 ± 3.0 years, with 10.0 ± 5.2 oocytes warmed per patient. 52/231 (22.5%) patients exclusively had ART using fresh oocytes, at a mean age of 39.0 ± 2.8 years, with 9.9 ± 7.4 mature oocytes retrieved per patient. CLBR was 37/90 (41.1%) in the oocyte warming-only group and 25/52 (48.1%) in the OS-only group. MR/transfer was 25.0% and 29.3% in the oocyte warming-only group and the OS-only group, respectively. Limitations, reasons for caution Both the small sample size and the retrospective design are limitations of this study. The decision to embark on a specific reproductive treatment strategy was based on patient preference, after counseling of treatment options. This precludes direct comparison of the efficacy of reproductive treatment options in past EOC users. Wider implications of the findings Reporting of clinical outcomes of women who underwent EOC and returned to the clinic to embark on divergent reproductive treatment strategies is mandatory to establish guidelines for best clinical practice in this growing patient population. Trial registration number Not applicable

Progesterone initiates tendril formation in the oviducal gland during egg encapsulation in cloudy catshark (Scyliorhinus torazame)

The diverse reproductive strategies of elasmobranchs (sharks, rays, and skates) have attracted research attention, but the endocrine control of reproduction is still incompletely known in elasmobranchs. By long-term monitoring of the egg-laying cycle in cloudy catsharks (Scyliorhinus torazame), we recently demonstrated a transient increase in plasma progesterone (P4) levels just prior to the appearance of the capsulated eggs in the oviducts. In the present study, we examined the in vivo effects of P4 administration in mature female cloudy catsharks. Although no capsulated eggs were observed following the implantation of P4-containing silicone tubing, we did find dark swollen oviducts in the abdominal cavity, in which clumps of long and coiled tendrils were observed. The tendril is an extension of the egg capsule, and the formation of the egg capsule begins with the tendril before main capsule formation. During the period of P4 implantation, the tendrils elongated, and their diameters were significantly increased on day 2 of treatment. Tendril formation was also confirmed on the day of endogenous P4 surge. Tendrils were not formed in catsharks implanted with estradiol-17β or testosterone. Histological analysis of the oviducal gland revealed that P4 implantation induced the secretion of tendril materials from the secretory tubules in the baffle zone, while the tendril materials were stored in the cytoplasm of the secretory cells under low P4 condition. Morphometrically, the area of secreted luminal materials in the secretory tubules was highly correlated to the diameter of tendrils. Our results suggest that the P4 surge during the egg-laying cycle serves as a trigger for egg capsule formation in the oviducal gland of cloudy catshark, but the hormonal signals were incomplete as the main capsule was not formed. Further studies are required to identify the hormones required for ovulation and formation of the main egg capsule.

Sizing Up the Onychophoran Genome: Repeats, Introns, and Gene Family Expansion Contribute to Genome Gigantism in Epiperipatus broadwayi.

Genome assemblies are growing at an exponential rate and have proved indispensable for studying evolution but the effort has been biased toward vertebrates and arthropods with a particular focus on insects. Onychophora or velvet worms are an ancient group of cryptic, soil dwelling worms noted for their unique mode of prey capture, biogeographic patterns, and diversity of reproductive strategies. They constitute a poorly understood phylum of exclusively terrestrial animals that is sister group to arthropods. Due to this phylogenetic position, they are crucial in understanding the origin of the largest phylum of animals. Despite their significance, there is a paucity of genomic resources for the phylum with only one highly fragmented and incomplete genome publicly available. Initial attempts at sequencing an onychophoran genome proved difficult due to its large genome size and high repeat content. However, leveraging recent advances in long-read sequencing technology, we present here the first annotated draft genome for the phylum. With a total size of 5.6Gb, the gigantism of the Epiperipatus broadwayi genome arises from having high repeat content, intron size inflation, and extensive gene family expansion. Additionally, we report a previously unknown diversity of onychophoran hemocyanins that suggests the diversification of copper-mediated oxygen carriers occurred independently in Onychophora after its split from Arthropoda, parallel to the independent diversification of hemocyanins in each of the main arthropod lineages.

The golden tip for better breeding: evidence for polyoestry in the golden-tipped bat (Phoniscus papuensis)

As a worldwide taxon inhabiting a diverse range of habitats and environmental conditions, bats also demonstrate some of the greatest variation in reproductive strategies of any mammalian order. Whilst monoestry is the predominant mating pattern of bats within the temperate zone, polyoestry and variants of this mode are more prevalent at tropical latitudes. As a tropical species occurring in a temperate climate in the southern extent of its range, the reproductive phenology of the golden-tipped bat (Phoniscus papuensis) is poorly understood. Here we present the first evidence of polyoestry in this species, an uncommon reproductive trait in Australian bats. The influence of weather and increase in prey density (orb-weaving spiders) are suggested as potential drivers for what appears to be a positive facultative breeding response to a pulse of resources. This observation demonstrates that there is still much to learn about the basic natural history and reproductive strategies of Australian bats.

The ecology and quantitative genetics of seed and seedling traits in upland and lowland ecotypes of a perennial grass.

Plants have evolved diverse reproductive allocation strategies and seed traits to aid in dispersal, persistence in the seed bank, and establishment. In particular, seed size, dormancy, and early seedling vigor are thought to be key functional traits with important recruitment and fitness consequences across abiotic stress gradients. Selection for favored seed-trait combinations, or against maladaptive combinations, is likely an important driver shaping recruitment strategies. Here, we test for seed-trait plasticity and patterns of recruitment using two genotypes representative of contrasting upland and lowland ecotypes of Panicum hallii with field experiments in native versus foreign habitats. Furthermore, we test whether seed traits have been under directional selection in P. hallii using the v-test based on trait variance in a genetic cross. Finally, we evaluate the genetic architecture of ecotypic divergence for these traits with quantitative trait locus (QTL) mapping. Field experiments reveal little plasticity but support a hypothesis of adaptation divergence among ecotypes based on recruitment. Patterns of segregation within recombinant hybrids provides strong support for directional selection driving ecotypic divergence in seed traits. Genetic mapping revealed a polygenic architecture with evidence of genetic correlation between seed mass, dormancy, and seedling vigor. Our results suggest that the evolution of these traits may involve constraints that affect the direction of adaptive divergence. For example, seed size and germination percentage shared two colocalized QTL with antagonistic additive effects. This supports the hypothesis of a functional genetic relationship between these traits, resulting in either large seed/strong dormancy or small seed/weak dormancy trait combinations. Overall, our study provides insights into the factors facilitating and potentially constraining ecotypic differentiation in seed traits.

Sex-Specific Effects of Blood Serotonin on Reproductive Effort in a Small Passerine.

AbstractLaboratory animal models have shown that blood serotonin levels reflect consistent individual differences in behavioral decision-making and maternal behavior. Serotonin could also help to understand intraspecific variation in reproductive strategies, although the mechanisms are poorly understood. In this study, the relationships of plasma serotonin with breeding parameters and parental behavior were examined in wild great tits (Parus major). Females who laid eggs earlier had higher levels of serotonin in the second half of the nestling period, while no significant relationship of serotonin with clutch size, brood size, and body size was detected. In males, serotonin levels were negatively related to clutch size and brood size and positively related to body size. The association of serotonin with provisioning behavior was sex specific, and acute fear stress induced by a predator presentation did not change this relationship. Food provisioning was positively related to size-corrected serotonin levels in females and negatively related to size-corrected serotonin levels in males. These results suggest that peripheral serotonin is a sensitive marker of parental behavior and reproductive effort in wild birds, while the mechanisms linking this neurotransmitter to reproduction are probably mediated by interplay between the serotonergic system, sex hormones, and other neurotransmitters.

Evolution in reproductive tempo and investment across the Peromyscus radiation.

Mammals display diverse reproductive strategies, however, the ultimate and proximate mechanisms that underlie this diversity and its composite traits remain poorly understood from both evolutionary and physiological perspectives. The Peromyscus genus of rodents, which is found throughout the north and central Americas, has diversified along life history gradients, varying both within and among species in reproductive strategies. This variation provides a useful model for studying reproductive diversity. Here, we combine a literature review with new analyses of captive colony breeding records from sixPeromyscus species to assess our current understanding of how plasticity and local adaptation contribute to diversity in two classes of reproductive traits: phenology and litter investment. There is substantial evidence that many traits underlying phenology and litter investment have diverged among populations in ways that are likely to be locally adaptive, though plasticity in these traits remains common. However, these conclusions are largely based on data collected from the two most widespread Peromyscus species: P. maniculatus and P. leucopus. The majority of Peromyscus species diversity remains understudied regarding reproductive phenology and litter traits. We conclude by discussing key challenges and considerations relevant to using Peromyscus as a mammalian model for reproductive trait diversity and evolution moving forward.

Reproductive strategies of a lizard community from an arid environment of Mexico

The goal of this study is to describe patterns of reproductive activity and associated characteristics in a lizard community from an arid environment in the southern Chihuahuan Desert region of Mexico. Results of this study showed variation in snout–vent length (SVL) in adults female and male among 18 species. A similar pattern occurred in body mass of males and females, which varied mainly among species and not substantially between sexes. Mean clutch/litter size and egg/embryo mass and volume varied among species, and egg/embryo mass and volume were positively correlated with female SVL. Oviparous species were larger in SVL than viviparous species; however, SVL in females, clutch/litter size and egg/embryo volume were similar between oviparous and viviparous species, but the oviductal mass of oviparous species was larger than in viviparous species. Clutch/litter size and oviductal mass were correlated with female SVL in both oviparous and viviparous species. This relationship was similar for egg/embryo volume in oviparous species, but not in viviparous species. Seven species showed a prolonged reproductive period, and five had short reproductive periods. The results of this study provide evidence of high diversity in reproductive strategies that have evolved among organisms that live in this environment.

Long-term monitoring of egg-laying cycle using ultrasonography reveals the reproductive dynamics of circulating sex steroids in an oviparous catshark, Scyliorhinus torazame

The many diverse reproductive strategies of elasmobranchs (sharks, skates and rays) from lecithotrophic oviparity to matrotrophic viviparity have attracted significant research attention. However, the endocrine control of elasmobranch reproduction is less well-documented largely due to their reproductive characteristics, such as a long reproductive cycle, and/or repeated internal fertilization using stored sperm in oviparous species. In the present study, for the first time, we succeeded in non-invasive monitoring of the continuing egg-laying cycle of the cloudy catshark Scyliorhinus torazame using portable ultrasound devices. Furthermore, long-term simultaneous monitoring of the egg-laying cycle and measurement of plasma sex steroids revealed cycling patterns of estradiol-17β (E2), testosterone (T) and progesterone (P4). In particular, a decline in T followed by a reciprocal surge in plasma P4 were consistently observed prior to the appearance of the capsulated eggs, implying that P4 is likely associated with the ovulation and/or egg-case formation. While the cycling pattern of E2 was not as apparent as those of T and P4, threshold levels of E2 (>5 ng/mL) and T (>1 ng/mL) appeared to be crucial in the continuation of egg-laying cycle. The possibility to trace the dynamics of plasma sex steroids in a single individual throughout the reproductive cycles makes the catshark a useful model for regulatory and mechanistic studies of elasmobranch reproduction.

Genetic Variation in Reproductive Investment Across an Ephemerality Gradient in Daphnia pulex.

Species across the tree of life can switch between asexual and sexual reproduction. In facultatively sexual species, the ability to switch between reproductive modes is often environmentally dependent and subject to local adaptation. However, the ecological and evolutionary factors that influence the maintenance and turnover of polymorphism associated with facultative sex remain unclear. We studied the ecological and evolutionary dynamics of reproductive investment in the facultatively sexual model species, Daphnia pulex. We found that patterns of clonal diversity, but not genetic diversity varied among ponds consistent with the predicted relationship between ephemerality and clonal structure. Reconstruction of a multi-year pedigree demonstrated the coexistence of clones that differ in their investment into male production. Mapping of quantitative variation in male production using lab-generated and field-collected individuals identified multiple putative quantitative trait loci (QTL) underlying this trait, and we identified a plausible candidate gene. The evolutionary history of these QTL suggests that they are relatively young, and male limitation in this system is a rapidly evolving trait. Our work highlights the dynamic nature of the genetic structure and composition of facultative sex across space and time and suggests that quantitative genetic variation in reproductive strategy can undergo rapid evolutionary turnover.

Claspers in the mid-CambrianOlenoides serratusindicate horseshoe crab–like mating in trilobites

AbstractSexual reproduction represents a fundamental aspect of animal biology, but the diversity of reproductive strategies among early Paleozoic metazoans remains obscure. Direct evidence of reproductive strategies comes from exceptionally preserved egg masses in Cambrian and Ordovician euarthropods such as waptiids and trilobites, but anatomical or behavioral adaptations for mating in these taxa are all but unknown. We demonstrate the presence of functionally specialized appendages in the mid-Cambrian (Wuliuan) Burgess Shale trilobite Olenoides serratus. New material of O. serratus preserves significantly modified and reduced endopodites underneath the seventh thoracic and first pygidial tergites. Comparison with extant euarthropods indicates that these specialized limbs are functional analogs to claspers, which are used by sexually mature males to grasp females prior to or during mating. The claspers in O. serratus were most likely used by the male to hold onto the posterior pygidial spines of the female during amplex, similar to the strategy observed in the horseshoe crab Limulus polyphemus. The new appendicular data from O. serratus provide the first direct evidence for trilobite sexual dimorphism based on the non-biomineralized ventral anatomy. Our findings illuminate the reproductive biology of trilobites and indicate that complex mating behaviors observed in extant euarthropods originated during the Cambrian explosion.

Geographic dispersion of invasive crop pests: the role of basal, plastic climate stress tolerance and other complementary traits in the tropics.

Global pest invasions have significantly increased in recent years. These invasions together with climate warming directly impact agriculture. Tropical climates feature extreme weather events, including high temperatures and seasonal droughts. Thus, successful invasive pests in tropics have to adapt to these extreme climate features. The intrinsic factors relevant to tropical invasion of insects have been explored in many studies, but the knowledge is rather dispersed in contemporary literature. Here, we reviewed the potential biophysical characters of successful invasive pests' adaption to tropical environments including [1] inherent high basal stress tolerance and advanced life-history performances [2], phenotypic plasticity [3], rapid evolution to environmental stress, polyphagy, diverse reproductive strategies and high fecundity. We summarised how these traits and their interactive effects enhance pest invasions in the tropics. Comprehensive understanding of how these characters facilitate invasion improves models for predicting ecological consequences of climate change on invasive pest species for improved pest management.

Evolution of reproductive strategies in incipient multicellularity.

Multicellular organisms potentially show a large degree of diversity in reproductive strategies, producing offspring with varying sizes and compositions compared to their unicellular ancestors. In reality, only a few of these reproductive strategies are prevalent. To understand why this could be the case, we develop a stage-structured population model to probe the evolutionary growth advantages of reproductive strategies in incipient multicellular organisms. The performance of reproductive strategies is evaluated by the growth rates of the corresponding populations. We identify the optimal reproductive strategy, leading to the largest growth rate for a population. Considering the effects of organism size and cellular interaction, we found that distinct reproductive strategies could perform uniquely or equally well under different conditions. If a single reproductive strategy is optimal, it is binary splitting, dividing into two parts. Our results show that organism size and cellular interaction can play crucial roles in shaping reproductive strategies in nascent multicellularity. Our model sheds light on understanding the mechanism driving the evolution of reproductive strategies in incipient multicellularity. Beyond multicellularity, our results imply that a crucial factor in the evolution of unicellular species’ reproductive strategies is organism size.

Tadpole-transporting frogs use stagnant water odor to find pools in the rainforest.

ABSTRACTBreeding sites are often a limited and ephemeral resource for rainforest frogs. This resource limitation has driven the evolution of diverse reproductive strategies that increase offspring survival. For example, poison frogs shuttle their tadpoles from terrestrial clutches to aquatic rearing sites, using various cues to assess pool suitability. Yet, how frogs find new pools is unknown. We tested the role of odor cues in the process of finding tadpole deposition sites by the poison frog Allobates femoralis. We created 60 artificial pools grouped into three conditions: stagnant water, tadpole water and clean water control. Fifteen pools were discovered within 6 days, with more tadpoles and more frogs directly observed at pools with stagnant odor cues. Our findings suggest that frogs use odor cues associated with stagnant water for the initial discovery of new breeding pools. These cues may be good indicators of pool stability and increased likelihood of tadpole survival.

Breeding systems of naturalized versus indigenous species provide support for Baker's law on Pohnpei island.

The factors that facilitate successful colonization of islands should be especially evident where the establishment filter is strongest. Colonizers of small, remote oceanic islands should be initially rare, extremely mate-limited and often without pollinators. Hence, plant communities on such islands should reflect an establishment history in which young ‘naturalized’ species are most likely to display self-compatibility and autonomous selfing, whereas ‘indigenous’ species may exhibit more diverse reproductive strategies. To test this prediction, we characterized breeding systems of 28 species on Pohnpei, in the Federated States of Micronesia, a group of remote Pacific islands that are considered a global biodiversity hotspot. Three families with both naturalized and indigenous species were selected—Fabaceae, Malvaceae and Melastomataceae. Measurements included field observations of dichogamy/herkogamy and floral attraction traits, pollen:ovule (P:O) ratios and experimental hand-pollinations for self-compatibility and pollen limitation. Phylogenetic generalized least squares analyses tested for trait correlations between naturalized and indigenous species. Flowers of all 28 species were bisexual, and pollinator attraction features were common. Pollen:ovule ratios ranged from 9 to 557 (median = 87), and all 11 hand-pollinated species were self-compatible. All species had >5 ovules and <3500 pollen grains per flower. Indigenous species did not differ significantly from naturalized species for any trait. There is a dearth of data from remote islands bearing on the question of establishment history. In this study, we inferred all species to have some degree of autogamy and indigenous species were no more likely than naturalized species to display outcrossing mechanisms. On Pohnpei, high ovule numbers, and the inaccessibility of wind pollination and obligate outcrossing strategies, reflect the importance of retaining reproductive assurance mechanisms in the face of pollinator uncertainty.

Reproductive trait differences drive offspring production in urban cavity-nesting bees and wasps.

The contrasting and idiosyncratic changes in biodiversity that have been documented across urbanization gradients call for a more mechanistic understanding of urban community assembly. The reproductive success of organisms in cities should underpin their population persistence and the maintenance of biodiversity in urban landscapes. We propose that exploring individual‐level reproductive traits and environmental drivers of reproductive success could provide the necessary links between environmental conditions, offspring production, and biodiversity in urban areas. For 3 years, we studied cavity‐nesting solitary bees and wasps in four urban green space types across Toronto, Canada. We measured three reproductive traits of each nest: the total number of brood cells, the proportion of parasite‐free cells, and the proportion of non‐emerged brood cells that were parasite‐free. We determined (a) how reproductive traits, trait diversity and offspring production respond to multiple environmental variables and (b) how well reproductive trait variation explains the offspring production of single nests, by reflecting the different ways organisms navigate trade‐offs between gathering of resources and exposure to parasites. Our results showed that environmental variables were poor predictors of mean reproductive trait values, trait diversity, and offspring production. However, offspring production was highly positively correlated with reproductive trait evenness and negatively correlated with trait richness and divergence. This suggests that a narrow range of reproductive traits are optimal for reproduction, and the even distribution of individual reproductive traits across those optimal phenotypes is consistent with the idea that selection could favor diverse reproductive strategies to reduce competition. This study is novel in its exploration of individual‐level reproductive traits and its consideration of multiple axes of urbanization. Reproductive trait variation did not follow previously reported biodiversity‐urbanization patterns; the insensitivity to urbanization gradients raise questions about the role of the spatial mosaic of habitats in cities and the disconnections between different metrics of biodiversity.

Jewish pronatalism: Policy and praxis

AbstractPronatalism is the practice and ideology of encouraging biological reproduction. While many religions as well as national and ethnic identities can be described as pronatalist, scholarship about reproduction among Jews often describes Jews and Judaism as foundationally and absolutely pronatalist. This article demonstrates the nuances of existing pronatalism in Jewish policy and practice, and highlights diverse reproductive practices and strategies among Jews in order to demonstrate that pronatalism is not the sum total of Jewish reproductive policy, advocacy, or praxis. Section 2 provides a brief overview of some of the biblical and rabbinic sources that many view as religious roots for Jewish prontalism. The sections 3.1 and 3.2 focus on Jewish pronatalism in Israel and America. Throughout this article, we will see how pronatalism has been applied and internalized through ethnic, racial, and able‐bodied lenses. While pronatalism is undoubtedly a strong cultural and religious force, this article provides a nuanced picture of reproduction among Jews by considering reproductive practices and strategies of Jewish women to be in conversation with pronatalist policies and ideologies. By decentering pronatalism in the study of reproduction and attitudes toward reproduction, we see that demographic continuity is just one of many considerations in Jewish reproductive practices.