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1.
    
Poleward range expansions are widespread responses to recent climate change and are crucial for the future persistence of many species. However, evolutionary change in traits such as colonization history and habitat preference may also be necessary to track environmental change across a fragmented landscape. Understanding the likelihood and speed of such adaptive change is important in determining the rate of species extinction with ongoing climate change. We conducted an amplified fragment length polymorphism (AFLP)‐based genome scan across the recently expanded UK range of the Brown Argus butterfly, Aricia agestis, and used outlier‐based (DFDIST and BayeScan) and association‐based (Isolation‐By‐Adaptation) statistical approaches to identify signatures of evolutionary change associated with range expansion and habitat use. We present evidence for (i) limited effects of range expansion on population genetic structure and (ii) strong signatures of selection at approximately 5% AFLP loci associated with both the poleward range expansion of A. agestis and differences in habitat use across long‐established and recently colonized sites. Patterns of allele frequency variation at these candidate loci suggest that adaptation to new habitats at the range margin has involved selection on genetic variation in habitat use found across the long‐established part of the range. Our results suggest that evolutionary change is likely to affect species’ responses to climate change and that genetic variation in ecological traits across species’ distributions should be maximized to facilitate range shifts across a fragmented landscape, particularly in species that show strong associations with particular habitats.  相似文献   

2.
    
Because the range boundary is the locale beyond which a taxon fails to persist, it provides a unique opportunity for studying the limits on adaptive evolution. Adaptive constraints on range expansion are perplexing in view of widespread ecotypic differentiation by habitat and region within a species' range (regional adaptation) and rapid evolutionary response to novel environments. In this study of two parapatric subspecies, Clarkia xantiana ssp. xantiana and C. x. ssp. parviflora, we compared the fitness of population transplants within their native region, in a non-native region within the native range, and in the non-native range to assess whether range expansion might be limited by a greater intensity of selection on colonists of a new range versus a new region within the range. The combined range of the two subspecies spans a west-to-east gradient of declining precipitation in the Sierra Nevada of California, with ssp. xantiana in the west being replaced by ssp. parviflora in the east. Both subspecies had significantly higher fitness in the native range (range adaptation), whereas regional adaptation was weak and was found only in the predominantly outcrossing ssp. xantiana but was absent in the inbreeding ssp. parvifilora. Because selection intensity on transplants was much stronger in the non-native range relative to non-native regions, there is a larger adaptive barrier to range versus regional expansion. Three of five sequential fitness components accounted for regional and range adaptation, but only one of them, survivorship from germination to flowering, contributed to both. Flower number contributed to regional adaptation in ssp. xantiana and fruit set (number of fruits per flower) to range adaptation. Differential survivorship of the two taxa or regional populations of ssp. xantiana in non-native environments was attributable, in part, to biotic interactions, including competition, herbivory, and pollination. For example, low fruit set in ssp. xantiana in the east was likely due to the absence of its principal specialist bee pollinators in ssp. parviflora's range. Thus, convergence on self-fertilization may be necessary for ssp. xantiana to invade ssp. parviflora's range, but the evolution of outcrossing would not be required for ssp. parviflora to invade ssp. xantiana's range.  相似文献   

3.
    
Biologists have recently devoted increasing attention to the role of rapid evolution in species' responses to environmental change. However, it is still unclear what evolutionary responses should be expected, at what rates, and whether evolution will save populations at risk of extinction. The potential of biological invasions to provide useful insights has barely been realised, despite the close analogies to species responding to global change, particularly climate change; in both cases, populations encounter novel climatic and biotic selection pressures, with expected evolutionary responses occurring over similar timescales. However, the analogy is not perfect, and invasive species are perhaps best used as an upper bound on expected change. In this article, we review what invasive species can and cannot teach us about likely evolutionary responses to global change and the constraints on those responses. We also discuss the limitations of invasive species as a model and outline directions for future research.  相似文献   

4.
    
Only model organisms live in a world of endless summer. Fitness at temperate latitudes reflects the ability of organisms in nature to exploit the favorable season, to mitigate the effects of the unfavorable season, and to make the timely switch from one life style to the other. Herein, we define fitness as Ry, the year-long cohort replacement rate across all four seasons, of the mosquito, Wyeomyia smithii, reared in its natural microhabitat in processor-controlled environment rooms. First, we exposed cohorts of W. smithii, from southern, midlatitude, and northern populations (30-50 degrees N) to southern and northern thermal years during which we factored out evolved differences in photoperiodic response. We found clear evidence of evolved differences in heat and cold tolerance among populations. Relative cold tolerance of northern populations became apparent when populations were stressed to the brink of extinction; relative heat tolerance of southern populations became apparent when the adverse effects of heat could accumulate over several generations. Second, we exposed southern, midlatitude, and northern populations to natural, midlatitude day lengths in a thermally benign midlatitude thermal year. We found that evolved differences in photoperiodic response (1) prevented the timely entry of southern populations into diapause resulting in a 74% decline in fitness, and (2) forced northern populations to endure a warm-season diapause resulting in an 88% decline in fitness. We argue that reciprocal transplants across latitudes in nature always confound the effects of the thermal and photic environment on fitness. Yet, to our knowledge, no one has previously held the thermal year constant while varying the photic year. This distinction is crucial in evaluating the potential impact of climate change. Because global warming in the Northern Hemisphere is proceeding faster at northern than at southern latitudes and because this change represents an amelioration of the thermal environment and a concomitant increase in the duration of the growing season, we conclude that there should be more rapid evolution of photoperiodic response than of thermal tolerance as a consequence of global warming among northern, temperate ectotherms.  相似文献   

5.
An urgent challenge facing biologists is predicting the regional-scale population dynamics of species facing environmental change. Biologists suggest that we must move beyond predictions based on phenomenological models and instead base predictions on underlying processes. For example, population biologists, evolutionary biologists, community ecologists and ecophysiologists all argue that the respective processes they study are essential. Must our models include processes from all of these fields? We argue that answering this critical question is ultimately an empirical exercise requiring a substantial amount of data that have not been integrated for any system to date. To motivate and facilitate the necessary data collection and integration, we first review the potential importance of each mechanism for skilful prediction. We then develop a conceptual framework based on reaction norms, and propose a hierarchical Bayesian statistical framework to integrate processes affecting reaction norms at different scales. The ambitious research programme we advocate is rapidly becoming feasible due to novel collaborations, datasets and analytical tools.  相似文献   

6.
1. The British distribution of the butterfly Gonepteryx rhamni (L.) follows closely the range of its natural host plants, Rhamnus catharticus L. and Frangula alnus Miller, suggesting that it is one of the few British butterflies that has a host‐limited distribution. In North Wales, this species has its range margin, and it was recorded only occasionally in a 35‐km2 area prior to the 1980s. Frangula alnus bushes were planted in the area in about 1986, allowing the hypothesis that G. rhamni would expand its range following increased host plant availability to be tested. 2. From 1996 to 1998, the distribution of the butterfly and its host plants, R. catharticus (native), Rhamnus alaternus L. (introduced), and F. alnus (introduced to the area but native to Britain), was mapped in the study area. It was found that the butterfly was more widespread than any of its host plants. Frangula alnus was the most widespread of the host plants, and received most eggs, suggesting that the carrying capacity of the habitat would have increased substantially following the planting of this species. Gonepteryx rhamni was able to complete its lifecycle on both introduced species in the study area. 3. A mark–release–recapture study showed that adult G. rhamni moved an average of 512 m, and 50% of movements were further than 400 m; these values are underestimates. The relatively high mobility of this species suggests that it probably perceives host plants and nectar sources as resource patches (patchy population) in this fragmented landscape, and this population now represents a satellite population of the butterfly's main distribution in Britain. 4. The results presented here confirm empirically the host‐limited distribution of G. rhamni, which expanded following the planting of extra host plants.  相似文献   

7.
    
A rapidly growing body of literature documents the potential negative effects of CO2‐driven ocean acidification (OA) on marine organisms. However, nearly all this work has focused on the effects of future conditions on modern populations, neglecting the role of adaptation. Rapid evolution can alter demographic responses to environmental change, ultimately affecting the likelihood of population persistence, but the capacity for adaptation will differ among populations and species. Here, we measure the capacity of the ecologically important purple sea urchin Strongylocentrotus purpuratus to adapt to OA, using a breeding experiment to estimate additive genetic variance for larval size (an important component of fitness) under future high‐pCO2/low‐pH conditions. Although larvae reared under future conditions were smaller than those reared under present‐day conditions, we show that there is also abundant genetic variation for body size under elevated pCO2, indicating that this trait can evolve. The observed heritability of size was 0.40 ± 0.32 (95% CI) under low pCO2, and 0.50 ± 0.30 under high‐pCO2 conditions. Accounting for the observed genetic variation in models of future larval size and demographic rates substantially alters projections of performance for this species in the future ocean. Importantly, our model shows that after incorporating the effects of adaptation, the OA‐driven decrease in population growth rate is up to 50% smaller, than that predicted by the ‘no‐adaptation’ scenario. Adults used in the experiment were collected from two sites on the coast of the Northeast Pacific that are characterized by different pH regimes, as measured by autonomous sensors. Comparing results between sites, we also found subtle differences in larval size under high‐pCO2 rearing conditions, consistent with local adaptation to carbonate chemistry in the field. These results suggest that spatially varying selection may help to maintain genetic variation necessary for adaptation to future OA.  相似文献   

8.
We must consider the role of multitrophic interactions when examining species' responses to climate change. Many plant species, particularly trees, are limited in their ability to shift their geographic ranges quickly under climate change. Consequently, for herbivorous insects, geographic mosaics of host plant specialization could prohibit range shifts and adaptation when insects become separated from suitable host plants. In this study, we examined larval growth and survival of an oak specialist butterfly (Erynnis propertius) on different oaks (Quercus spp.) that occur across its range to determine if individuals can switch host plants if they move into new areas under climate change. Individuals from Oregon and northern California, USA that feed on Q. garryana and Q. kelloggii in the field experienced increased mortality on Q. agrifolia, a southern species with low nutrient content. In contrast, populations from southern California that normally feed on Q. agrifolia performed well on Q. agrifolia and Q. garryana and poorly on the northern, high elevation Q. kelloggii. Therefore, colonization of southern E. propertius in higher elevations and some northern locales may be prohibited under climate change but latitudinal shifts to Q. garryana may be possible. Where shifts are precluded due to maladaptation to hosts, populations may not accrue warm‐adapted genotypes. Our study suggests that, when interacting species experience asynchronous range shifts, historical local adaptation may preclude populations from colonizing new locales under climate change.  相似文献   

9.
    
Poleward range expansions are observed for an increasing number of species, which may be an effect of global warming during the past decades. However, it is still not clear in how far these expansions reflect simple geographical shifts of species ranges, or whether new genetic adaptations play a role as well. Here, we analyse the expansion of the wasp spider Argiope bruennichi into Northern Europe during the last century. We have used a range‐wide sampling of contemporary populations and historical specimens from museums to trace the phylogeography and genetic changes associated with the range shift. Based on the analysis of mitochondrial, microsatellite and SNP markers, we observe a higher level of genetic diversity in the expanding populations, apparently due to admixture of formerly isolated lineages. Using reciprocal transplant experiments for testing overwintering tolerance, as well as temperature preference and tolerance tests in the laboratory, we find that the invading spiders have possibly shifted their temperature niche. This may be a key adaptation for survival in Northern latitudes. The museum samples allow a reconstruction of the invasion's genetic history. A first, small‐scale range shift started around 1930, in parallel with the onset of global warming. A more massive invasion of Northern Europe associated with genetic admixture and morphological changes occurred in later decades. We suggest that the latter range expansion into far Northern latitudes may be a consequence of the admixture that provided the genetic material for adaptations to new environmental regimes. Hence, global warming could have facilitated the initial admixture of populations and this resulted in genetic lineages with new habitat preferences.  相似文献   

10.
    
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11.
  总被引:1,自引:0,他引:1  
Abstract.  1. Operophtera brumata L. (Lepidoptera: Geometridae), a polyphagous herbivore usually associated with deciduous trees such as oak Quercus robur L . , has expanded its host range to include the evergreen species heather Calluna vulgaris (L.) Hull and, most recently, Sitka spruce Picea sitchensis (Bong.) Carrière.
2. Phenology, morphology, and survival of O. brumata were measured at several life-history stages in populations from the three different host plant communities sampled from a range of geographical locations. The data were used to test for population differences, reflecting the marked differences in host-plant secondary chemistry, growth form, and site factors such as climate. The hypothesis that spruce-feeding populations originated from populations feeding on moorland, commonly sites of coniferous afforestation, was also tested.
3. Altitude, not host plant species, was the major influence on the timing of adult emergence. An effect of insect population independent of altitude was found, implying that additional unidentified factors contribute to this phenological variation. Larval survival and adult size varied between populations reared on different host plant species. Survival of larvae was affected negatively when reared on the novel host plant, Sitka spruce, versus the natal plant (oak or heather) but oak and heather-sourced insects did not differ in survivorship on Sitka spruce.
4. Host range extension into novel environments has resulted in population differentiation to the local climate, demonstrating that host shifts pose challenges to the herbivore population greater than those offered by the host plant alone. The hypothesis that Sitka spruce feeding populations have arisen predominantly from moorland feeding populations was not supported.  相似文献   

12.
13.
    
Adaptive phenotypic plasticity may improve the response of individuals when faced with new environmental conditions. Typically, empirical evidence for plasticity is based on phenotypic reaction norms obtained in reciprocal transplant experiments. In such experiments, individuals from their native environment are transplanted into a different environment, and a number of trait values, potentially implicated in individuals' response to the new environment, are measured. However, the interpretations of reaction norms may differ depending on the nature of the assessed traits, which may not be known beforehand. For example, for traits that contribute to local adaptation, adaptive plasticity implies nonzero slopes of reaction norms. By contrast, for traits that are correlated to fitness, high tolerance to different environments (possibly due to adaptive plasticity in traits that contribute to adaptation) may, instead, result in flat reaction norms. Here we investigate reaction norms for adaptive versus fitness-correlated traits and how they may affect the conclusions regarding the contribution of plasticity. To this end, we first simulate range expansion along an environmental gradient where plasticity evolves to different values locally and then perform reciprocal transplant experiments in silico. We show that reaction norms alone cannot inform us whether the assessed trait exhibits locally adaptive, maladaptive, neutral, or no plasticity, without any additional knowledge of the traits assessed and species' biology. We use the insights from the model to analyse and interpret empirical data from reciprocal transplant experiments involving the marine isopod Idotea balthica sampled from two geographical locations with different salinities, concluding that the low-salinity population likely has reduced adaptive plasticity relative to the high-salinity population. Overall, we conclude that, when interpreting results from reciprocal transplant experiments, it is necessary to consider whether traits assessed are locally adaptive with respect to the environmental variable accounted for in the experiments or correlated to fitness.  相似文献   

14.
15.
A northward shift of range margins in British Odonata   总被引:4,自引:0,他引:4  
Many species are predicted to shift their ranges to higher latitudes and altitudes in response to climate warming. This study presents evidence for 37 species of nonmigratory British dragonflies and damselflies shifting northwards at their range margins over the past 40 years, seemingly as a result of climate change. This response by an exemplar group of insects associated with fresh water, parallels polewards range changes observed in terrestrial invertebrates and other taxa.  相似文献   

16.
    
1. This study provides evidence that a heliophilic butterfly, the Glanville fritillary (Melitaea cinxia) has adapted differently to environmental variation across latitudes and elevations. 2. In cool air, basking M. cinxia orient themselves perpendicular to the sun's rays to gain heat and take off. During flight, solar heating is reduced because orientation perpendicular to the sun is no longer possible and convective cooling occurs. Consequently, M. cinxia have been shown to suffer net heat loss in flight, even in full sunshine. When flight duration is restricted in this way, the takeoff temperature becomes an important thermal adaptation. 3. Using a thermal imaging camera, takeoff temperatures were measured in experimental butterflies. Butterflies from the northern range limit in Finland took flight at slightly hotter temperatures than butterflies from the southern limit in Spain, and much hotter than butterflies from the elevational limit (1900–2300 m) in the French Alps. Butterflies from low‐elevation populations in southern France also took off much hotter than did the nearby Alpine population. 4. These results suggest that the influence of elevation is different from that of latitude in more respects than ambient temperature. Values of solar irradiance in the butterflies' flight season in each region show that insects from the coolest habitats, Finland and the Alps, experienced similar solar irradiance during basking, but that Finns experienced much lower irradiance in flight. This difference may have favored Finnish butterflies evolving higher takeoff temperatures than Alpine butterflies that also flew in cool air but benefited from more intense radiant energy after takeoff.  相似文献   

17.
    
Species range expansions are crucial for understanding niche formation and the interaction with the environment. Here, we studied the bumblebee Bombus haematurus Kriechbaumer, 1870, a species historically distributed from northern Serbia through northern Iran which has very recently started expanding northwestward into Central Europe without human-mediated dispersal (i.e., it is a natural spread). After updating the global distribution of this species, we investigated if niche shifts took place during this range expansion between newly colonized and historical areas. In addition, we have explored which climatic factors may have favored the natural range expansion of the species. Our results indicated that Bombus haematurus has colonized large territories in 7 European countries outside the historical area in the period from the 1980s to 2018, a natural expansion over an area that equals 20% of the historical distribution. In addition, this bumblebee performs generalism in flower visitation and it occurs in different habitats, although a preference for forested areas clearly emerges. The land-use associated with the species in the colonized areas is similar to the historical distribution, indicating that no major niche shifts occurred during the spread. Furthermore, in recently colonized localities, the range expansion was associated with warming temperatures during the winter and also during both queen overwintering and emergence phases. These findings document a case of natural range expansion due to environmental change rather than due to niche shifts, and specifically they suggest that warmer winters could be linked to the process of natural colonization of new areas.  相似文献   

18.
    
Theory generally predicts that host specialisation and dispersal should evolve jointly. Indeed, many models predict that specialists should be poor dispersers to avoid landing on unsuitable hosts while generalists will have high dispersal abilities. Phytophagous arthropods are an excellent group to test this prediction, given extensive variation in their host range and dispersal abilities. Here, we explore the degree to which the empirical literature on this group is in accordance with theoretical predictions. We first briefly outline the theoretical reasons to expect such a correlation. We then report empirical studies that measured both dispersal and the degree of specialisation in phytophagous arthropods. We find a correlation between dispersal and levels of specialisation in some studies, but with wide variation in this result. We then review theoretical attributes of species and environment that may blur this correlation, namely environmental grain, temporal heterogeneity, habitat selection, genetic architecture, and coevolution between plants and herbivores. We argue that theoretical models fail to account for important aspects, such as phenotypic plasticity and the impact of selective forces stemming from other biotic interactions, on both dispersal and specialisation. Next, we review empirical caveats in the study of this interplay. We find that studies use different measures of both dispersal and specialisation, hampering comparisons. Moreover, several studies do not provide independent measures of these two traits. Finally, variation in these traits may occur at scales that are not being considered. We conclude that this correlation is likely not to be expected from large-scale comparative analyses as it is highly context dependent and should not be considered in isolation from the factors that modulate it, such as environmental scale and heterogeneity, intrinsic traits or biotic interactions. A stronger crosstalk between theoretical and empirical studies is needed to understand better the prevalence and basis of the correlation between dispersal and specialisation.  相似文献   

19.
The coffee berry borer, Hypothenemus hampei (Coleoptera: Curculionidae: Scolytinae), is the most devastating insect pest of coffee throughout the world. The insect is endemic to Africa but can now be found throughout nearly all coffee‐producing countries. One area of basic biology of the insect that remains unresolved is that of its alternative host plants, i.e. which fruits of plants, other than coffee, can the insect survive and reproduce in. An in‐depth survey of the literature revealed an article by Schedl listing 21 genera in 13 families in which the insect was collected, mainly in the Democratic Republic of Congo. This overlooked reference, together with information provided in other early articles, suggests that H. hampei is polyphagous, and could provide, if confirmed in the field, critical information on the evolution of this insect's diet, ecology and host range. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, ??, ??–??.  相似文献   

20.
    
Dispersal ability will largely determine whether species track their climatic niches during climate change, a process especially important for populations at contracting (low‐latitude/low‐elevation) range limits that otherwise risk extinction. We investigate whether dispersal evolution at contracting range limits is facilitated by two processes that potentially enable edge populations to experience and adjust to the effects of climate deterioration before they cause extinction: (i) climate‐induced fitness declines towards range limits and (ii) local adaptation to a shifting climate gradient. We simulate a species distributed continuously along a temperature gradient using a spatially explicit, individual‐based model. We compare range‐wide dispersal evolution during climate stability vs. directional climate change, with uniform fitness vs. fitness that declines towards range limits (RLs), and for a single climate genotype vs. multiple genotypes locally adapted to temperature. During climate stability, dispersal decreased towards RLs when fitness was uniform, but increased when fitness declined towards RLs, due to highly dispersive genotypes maintaining sink populations at RLs, increased kin selection in smaller populations, and an emergent fitness asymmetry that favoured dispersal in low‐quality habitat. However, this initial dispersal advantage at low‐fitness RLs did not facilitate climate tracking, as it was outweighed by an increased probability of extinction. Locally adapted genotypes benefited from staying close to their climate optima; this selected against dispersal under stable climates but for increased dispersal throughout shifting ranges, compared to cases without local adaptation. Dispersal increased at expanding RLs in most scenarios, but only increased at the range centre and contracting RLs given local adaptation to climate.  相似文献   

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