Local adaptation has been a major focus of evolutionary ecologists working across diverse systems for decades. However, little of this research has explored variation at microgeographic scales because it has often been assumed that high rates of gene flow will prevent adaptive divergence at fine spatial scales. Here, we establish a quantitative definition of microgeographic adaptation based on Wright's dispersal neighborhood that standardizes dispersal abilities, enabling this measure to be compared across species. We use this definition to evaluate growing evidence of evolutionary divergence at fine spatial scales. We identify the main mechanisms known to facilitate this adaptation and highlight illustrative examples of microgeographic evolution in nature. Collectively, this evidence requires that we revisit our understanding of the spatial scale of adaptation and consider how microgeographic adaptation and its driving mechanisms can fundamentally alter ecological and evolutionary dynamics in nature.

Phenotypic plasticity and genetic adaptation are predicted to mitigate some of the negative biotic consequences of climate change. Here, we evaluate evidence for plastic and evolutionary responses to climate variation in amphibians and reptiles via a literature review and meta-analysis. We included studies that either document phenotypic changes through time or space. Plasticity had a clear and ubiquitous role in promoting phenotypic changes in response to climate variation. For adaptive evolution, we found no direct evidence for evolution of amphibians or reptiles in response to climate change over time. However, we found many studies that documented adaptive responses to climate along spatial gradients. Plasticity provided a mixture of adaptive and maladaptive responses to climate change, highlighting that plasticity frequently, but not always, could ameliorate climate change. Based on our review, we advocate for more experiments that survey genetic changes through time in response to climate change. Overall, plastic and genetic variation in amphibians and reptiles could buffer some of the formidable threats from climate change, but large uncertainties remain owing to limited data.

The field of landscape genetics has been evolving rapidly since its emergence in the early 2000s. New applications, techniques and criticisms of techniques appear like clockwork with each new journal issue. The developments are an encouraging, and at times bewildering, sign of progress in an exciting new field of study. However, we suggest that the rapid expansion of landscape genetics has belied important flaws in the development of the field, and we add an air of caution to this breakneck pace of expansion. Specifically, landscape genetic studies often lose sight of the fundamental principles and complex consequences of gene flow, instead favouring simplistic interpretations and broad inferences not necessarily warranted by the data. Here, we describe common pitfalls that characterize such studies, and provide practical guidance to improve landscape genetic investigation, with careful consideration of inferential limits, scale, replication, and the ecological and evolutionary context of spatial genetic patterns. Ultimately, the utility of landscape genetics will depend on translating the relationship between gene flow and landscape features into an understanding of long‐term population outcomes. We hope the perspective presented here will steer landscape genetics down a more scientifically sound and productive path, garnering a field that is as informative in the future as it is popular now.

Introduction Evidence on perinatal mental health during the coronavirus disease 2019 (COVID‐19) pandemic and its potential determinants is limited. Therefore, this multinational study aimed to assess the mental health status of pregnant and breastfeeding women during the pandemic, and to explore potential associations between depressive symptoms, anxiety, and stress and women's sociodemographic, health, and reproductive characteristics. Material and methods A cross‐sectional, web‐based study was performed in Ireland, Norway, Switzerland, the Netherlands, and the UK between 16 June and 14 July 2020. Pregnant and breastfeeding women up to 3 months postpartum who were older than 18 years of age were eligible. The online, anonymous survey was promoted through social media and hospital websites. The Edinburgh Depression Scale (EDS), the Generalized Anxiety Disorder seven‐item scale (GAD‐7), and the Perceived Stress Scale (PSS) were used to assess mental health status. Regression model analysis was used to identify factors associated with poor mental health status. Results In total, 9041 women participated (including 3907 pregnant and 5134 breastfeeding women). The prevalence of major depressive symptoms (EDS ≥ 13) was 15% in the pregnancy cohort and and 13% the breastfeeding cohort. Moderate to severe generalized anxiety symptoms (GAD ≥ 10) were found among 11% and 10% of the pregnant and breastfeeding women. The mean (±SD) PSS scores for pregnant and breastfeeding women were 14.1 ± 6.6 and 13.7 ± 6.6, respectively. Risk factors associated with poor mental health included having a chronic mental illness, a chronic somatic illness in the postpartum period, smoking, having an unplanned pregnancy, professional status, and living in the UK or Ireland. Conclusions This multinational study found high levels of depressive symptoms and generalized anxiety among pregnant and breastfeeding women during the COVID‐19 outbreak. The study findings underline the importance of monitoring perinatal mental health during pandemics and other societal crises to safeguard maternal and infant mental health.

The physical and environmental attributes of landscapes often shape patterns of population connectivity by influencing dispersal and gene flow. Landscape effects on movement are typically evaluated for single species. However, inferences from multiple species are required for multi-species management strategies increasingly being applied in conservation. In this study, I compared the spatial genetic patterns of two amphibian species across the northeastern United States and estimated the influence of specific landscape features on the observed genetic structure. The spotted salamander (Ambystoma maculatum) and wood frog (Rana sylvatica) share many ecological attributes related to habitat use, phenology and site fidelity. However, I hypothesized that important differences in their movement patterns and life history would create distinct genetic patterns for each species. Using 14 microsatellite loci, I tested for differences in the level of genetic differentiation between the two species across 22 breeding ponds. The effects of eight landscape features were also estimated by evaluating 32 landscape resistance models. Spotted salamanders exhibited significantly higher genetic differentiation than wood frogs. Different landscape features were also identified as potential drivers of the genetic patterns in each species, with little overlap in model support between species. Collectively, these results provide strong evidence that these two amphibian species interact with the landscape in measurably different ways. The distinct genetic patterns observed are consistent with key differences in movement ability and life history between A. maculatum and R. sylvatica. These results highlight the importance of considering more than one species when assessing the impacts of the landscape matrix on population connectivity, even for ecologically similar species within the same habitats.

The fluctuations of the key East African lakes discussed are summarized in Fig. 4 which also includes the available evidence from Lake Rukwa (42) and Lake Chad (43) Exceot for Lake Victoria, all of these now lack surface outlets and are situated in much drier climates than the major lakes of the Western Rift Valley, which remain filled to their overflow levels. The apparent differendes among the fluctuations of the lakes are partly due to differendes in the nature of the evidence or the intensity of research or both, although there must also have been important local differences in the histories of the lakes Yet the consistencies are far more striking, most notably the coincidence of early Holocene high stands. Between 10,000 and 8,000 years ago, it seems that lakes in many parts of tropical Africa were greatly enlarged. Where evidence for the previous span of time is well resolved, it appears that transgressions leading to this high stand began about 12,000 years ago, and evidende from three basins (Victoria, Nakuru, and Chad) indicates a pause or minor recession just at or before 10,000 years ago. Wherever information is available for the period preceding 12,000 years ago, it can consistentlybe shown that lakes were much small-er . Several basins (Rudolf, Nakuru, and Chad) also show traces of much earlier phases of lake expansion. which are not yet well dated but which all occurred more then 20,000 years ago. The Holocene record subsequent to the maximum of 10,00 to 8,000 years ago is more complex. Three basins (Rudolf, Nakuru, and Chad) show an apparently concordant, positive oscillation at some point between 6000 and 4000 years ago, but it is uncertain how widely this episode is represented. Although many of these lakes that are now closed filled to overflowing at least once during the late Quaternary, it is evident from Fig. 4 that the periods of expansion were short-lived compared with phases of contraction to levels near those of today. This pattern may be in accord with fragmentary evidence from lower and middle Pleistocene formations, such as those of Olduvai(44)and Paninj (45), within which some relatively short-term lake expansions can be documented, but which lack evidence for any marked long-term departure from a balance of evaporation and precipitation similar to the present one Further, this pattern of brief moist pulsations, with a duration of perhaps 2000 to 5000 years, is also suggested by other late Pleistocene and Holocene sequences (based primarily on geomorphological and palynological evidence) from the Saharan area, Angola, and South Africa (46). In default of radiometric dating, such complex successions of relatively brief moist intervals provide few stratigraphic markers of broad applicability. This, together with the fact that vegetation, weathering processes, montane glaciers, lake size, lake salinity, and so forth are all likely to reflect the diverse aspects of Climatic change differently, underscores the strictures of Cooke (2) and Flint (3) against the use of pluvials and intrlvasas...

Analysis of a 28—m core from a relict fresh—water lake in Kenya had provided a detailed limnologic and climatic history covering 9,200 years. The core is an incomplete section through the sediments of a submerged crater near the eastern shore of Lake Naivasha. The overall sedimentation rate, 0.33 cm wet sediment per year, is the most rapid on record for a lake whose sediments are essentially autochthonous and organic. A three—stage limnologic history is inferred from the microfossils (particularly diatoms), chemistry, and mineralogy of the core: (A) From before 9,200 B.P. until about 5,650 B.P. a lake significantly larger than the present one existed in the basin. Algal productivity was high, and the water temperature was probably above the present average. The surface waters of this lake were evidently depleted in silica, suggesting some stratification, but the total ion content was not far below today's (B) Between 5,650 B.P. and 3,040 B.P. the lake shrank, aquatic macrophytes increased in abundance near the core site, and the water grew more dilute. The crater became isolated from the main lake and finally dried briefly. (C) For the past 3,000 years a small lake has existed in the basin. It has been frequently smaller and its water sometimes much more concentrated than that of the modern lake. The lake discharged through a southern outlet prior to 5,650 B.P., but since that time has had no surface outlet. Various freshening mechanisms have operated during the past 5,000 years, probably including deflation, burial of alkaline layers, underground seepage, and perhaps ion removal by aquatic plants. The climate during the period of the large lake (Leakey's Gamblian Pluvial period) was much wetter and probably warmer than today, and rainfall at Naivasha was more seasonal. Rainfall was perhaps 65% above the modern average. We find no convincing evidence for an early post—Gamblian wet phase, the Makalian, proposed by earlier workers for this region. A later wet phase, the Nakuran, may be represented by the small, fluctuating lake of the past 3,000 years, but this lake probably never stood as high as the strandline previously assigned to the Nakuran. The climatic inferences from this study are in substantial agreement, but provide interesting points of contrast, with those from other recent investigations in sub—Saharan Africa.

Human commensal species such as rodent pests are often widely distributed across cities and threaten both infrastructure and public health. Spatially explicit population genomic methods provide insights into movements for cryptic pests that drive evolutionary connectivity across multiple spatial scales. We examined spatial patterns of neutral genomewide variation in brown rats (Rattus norvegicus) across Manhattan, New York City (NYC), using 262 samples and 61,401 SNPs to understand (i) relatedness among nearby individuals and the extent of spatial genetic structure in a discrete urban landscape; (ii) the geographic origin of NYC rats, using a large, previously published data set of global rat genotypes; and (iii) heterogeneity in gene flow across the city, particularly deviations from isolation by distance. We found that rats separated by ≤200 m exhibit strong spatial autocorrelation (r = .3, p = .001) and the effects of localized genetic drift extend to a range of 1,400 m. Across Manhattan, rats exhibited a homogeneous population origin from rats that likely invaded from Great Britain. While traditional approaches identified a single evolutionary cluster with clinal structure across Manhattan, recently developed methods (e.g., fineS-TRUCTURE, sPCA, EEMS) provided evidence of reduced dispersal across the island's less residential Midtown region resulting in fine-scale genetic structuring (F ST = 0.01) and two evolutionary clusters (Uptown and Downtown Manhattan). Thus, while some urban populations of human commensals may appear to be continuously distributed, landscape heterogeneity within cities can drive differences in habitat quality and dispersal, with implications for the spatial distribution of genomic variation, population management and the study of widely distributed pests.