Division within the North American boreal forest: Ecological niche divergence between the Bicknell's Thrush (Catharus bicknelli) and Gray‐cheeked Thrush (C. minimus)

Sister species that diverged in allopatry in similar environments are expected to exhibit niche conservatism. Using ecological niche modeling and a multivariate analysis of climate and habitat data, I test the hypothesis that the Bicknell's Thrush (Catharus bicknelli) and Gray‐cheeked Thrush (C. mimimus), sister species that breed in the North American boreal forest, show niche conservatism. Three tree species that are important components of breeding territories of both thrush species were combined with climatic variables to create niche models consisting of abiotic and biotic components. Abiotic‐only, abiotic+biotic, and biotic‐only models were evaluated using the area under the curve (AUC) criterion. Abiotic+biotic models had higher AUC scores and did not over‐project thrush distributions compared to abiotic‐only or biotic‐only models. From the abiotic+biotic models, I tested for niche conservatism or divergence by accounting for the differences in the availability of niche components by calculating (1) niche overlap from ecological niche models and (2) mean niche differences of environmental values at occurrence points. Niche background similarity tests revealed significant niche divergence in 10 of 12 comparisons, and multivariate tests revealed niche divergence along 2 of 3 niche axes. The Bicknell's Thrush breeds in warmer and wetter regions with a high abundance of balsam fir (Abies balsamea), whereas Gray‐cheeked Thrush often co‐occurs with black spruce (Picea mariana). Niche divergence, rather than conservatism, was the predominant pattern for these species, suggesting that ecological divergence has played a role in the speciation of the Bicknell's Thrush and Gray‐cheeked Thrush. Furthermore, because niche models were improved by the incorporation of biotic variables, this study validates the inclusion of relevant biotic factors in ecological niche modeling to increase model accuracy.     

Phylogeny,Species Richness,and Ecological Specialization in Cyperaceae Tribe Cariceae

Cyperaceae tribe Cariceae is characterized by both species richness and habitat diversity, making it an ideal system to study ecological specialization and niche differentiation. We present a phylogenetic hypothesis for the tribe based on nuclear and chloroplast DNA sequence comparisons (ETS-1f, ITS, trnL intron, trnL-trnF intergenic spacer) for 140 representative species from five continents, and use this hypothesis to suggest patterns of both niche conservatism and niche differentiation, particularly within the large subgenus Carex. We identify a new major clade, comprising forest species of East Asian Carex section Siderostictae (subgenus Carex) as sister to the rest of tribe Cariceae. Within Carex subgenus Carex, species tolerant of water-saturated habitats occur in only a few, apparently derived groups, with varying species richness. Clades of predominantly wetland species tend to have broad geographic distribution, often with sister species on different continents, suggesting recent dispersal. In contrast, species within several clades are predominantly forest specialists with distinct Asian and North American lineages. Niche segregation along environmental gradients, such as soil moisture or acidity, is quite common among closely related wetland species, but more difficult to demonstrate within upland forest groups. More complete sampling of species within both wetland and forest groups, combined with comparable sampling of environmental preferences and testing against null models, will be needed for more rigorous exploration of the observed patterns.     

Linking the spatio‐temporal distribution of an edaphic crane fly to its heterogeneous soil environment

相似文献   

Stream flow alone does not predict population structure of diving beetles across complex tropical landscapes

Recent theoretical advances have hypothesized a central role of habitat persistence on population genetic structure and resulting biodiversity patterns of freshwater organisms. Here, we address the hypothesis that lotic species, or lineages adapted to comparably geologically stable running water habitats (streams and their marginal habitats), have high levels of endemicity and phylogeographic structure due to the persistent nature of their habitat. We use a nextRAD DNA sequencing approach to investigate the population structure and phylogeography of a putatively widespread New Guinean species of diving beetle, Philaccolilus ameliae (Dytiscidae). We find that P. ameliae is a complex of morphologically cryptic, but geographically and genetically well‐differentiated clades. The pattern of population connectivity is consistent with theoretical predictions associated with stable lotic habitats. However, in two clades, we find a more complex pattern of low population differentiation, revealing dispersal across rugged mountains and watersheds of New Guinea up to 430 km apart. These results, while surprising, were also consistent with the original formulation of the habitat template concept by Southwood, involving lineage‐idiosyncratic evolution in response to abiotic factors. In our system, low population differentiation might reflect a young species in a phase of range expansion utilizing vast available habitat. We suggest that predictions of life history variation resulting from the dichotomy between lotic and lentic organisms require more attention to habitat characterization and microhabitat choice. Our results also underpin the necessity to study fine‐scale processes but at a larger geographical scale, as compared to solely documenting macroecological patterns, to understand ecological drivers of regional biodiversity. Comprehensive sampling especially of tropical lineages in complex and threatened environments such as New Guinea remains a critical challenge.     

The great American biotic interchange and diversification history in Dynastes beetles (Scarabaeidae; Dynastinae)

Biotic interchange between geographic regions can promote rapid diversification. However, what are the important factors that determine the rate of diversification (e.g., trait‐dependent diversification) vary between study systems. The evolutionary history of Dynastes beetles, which can be found in both North and South Americas and exhibit two different altitudinal preferences (highland and lowland) is tested for the effects of biotic interchange between continents and different ecological preferences on the rate of species diversification. Additionally, the hypotheses of geological time‐dependent and lineage specific diversification rates are also tested. Results from this study indicate that in Dynastes beetles a pre‐landbridge dispersal hypothesis from South to North America is preferred and that the speciation rates estimated using BAMM are similar between lineages of different geographic origins and different altitudinal preferences (i.e., diversification rate is not trait‐dependent). On the other hand, my result from marcoevolutionary cohort analysis based on BAMM outputs suggests that the rate of speciation in Dynastes beetles is, instead of trait‐dependent (geographic and ecological), lineage specific. Furthermore, a steadily increasing speciation rate can be found in Pliocene and Pleistocene, which implies that geological and climatic events, i.e., colonizing North America, habitat reformation in the Amazonia, and forest contraction in Pleistocene, may have together shaped the current biodiversity pattern in Dynastes beetles.     

The scramble for Africa: pan-temperate elements on the African high mountains

The composition of isolated floras has long been thought to be the result of relatively rare long-distance dispersal events. However, it has recently become apparent that the recruitment of lineages may be relatively easy and that many dispersal events from distant but suitable habitats have occurred, even at an infraspecific level. The evolution of the flora on the high mountains of Africa has been attributed to the recruitment of taxa not only from the African lowland flora or the Cape Floristic Region, but also to a large extent from other areas with temperate climates. We used the species rich, pan-temperate genera Carex, Ranunculus and Alchemilla to explore patterns in the number of recruitment events and region of origin. Molecular phylogenetic analyses, parametric bootstrapping and ancestral area optimizations under parsimony indicate that there has been a high number of colonization events of Carex and Ranunculus into Africa, but only two introductions of Alchemilla. Most of the colonization events have been derived from Holarctic ancestors. Backward dispersal out of Africa seems to be extremely rare. Thus, repeated colonization from the Northern Hemisphere in combination with in situ radiation has played an important role in the composition of the flora of African high mountains.     

Speciation below ground: Tempo and mode of diversification in a radiation of endogean ground beetles

Dispersal is a critical factor determining the spatial scale of speciation, which is constrained by the ecological characteristics and distribution of a species’ habitat and the intrinsic traits of species. Endogean taxa are strongly affected by the unique qualities of the below‐ground environment and its effect on dispersal, and contrasting reports indicate either high dispersal capabilities favoured by small body size and mediated by passive mechanisms, or low dispersal due to restricted movement and confinement inside the soil. We studied a species‐rich endogean ground beetle lineage, Typhlocharina, including three genera and more than 60 species, as a model for the evolutionary biology of dispersal and speciation in the deep soil . A time‐calibrated molecular phylogeny generated from >400 individuals was used to delimit candidate species, to study the accumulation of lineages through space and time by species–area–age relationships and to determine the geographical structure of the diversification using the relationship between phylogenetic and geographic distances across the phylogeny. Our results indicated a small spatial scale of speciation in Typhlocharina and low dispersal capacity combined with sporadic long distance, presumably passive dispersal events that fuelled the speciation process. Analysis of lineage growth within Typhlocharina revealed a richness plateau correlated with the range of distribution of lineages, suggesting a long‐term species richness equilibrium mediated by density dependence through limits of habitat availability. The interplay of area‐ and age‐dependent processes ruling the lineage diversification in Typhlocharina may serve as a general model for the evolution of high species diversity in endogean mesofauna.     

Historical patterns of niche dynamics in Neotropical species of the <Emphasis Type="Italic">Drosophila</Emphasis> subgenus (Drosophilidae,Diptera)

Niche conservatism (NC) presence is a controversial question in evolutionary ecology. In Drosophila, little is known about which is the preponderant evolutionary pattern, since the adaptive radiation hypothesis first proposed by Throckmorton assumed niche divergence (ND) according to a niche occupancy scenario. Nevertheless, this hypothesis has not yet been straightforwardly tested. Our aim here was to test the role of NC patterns across evolution of American drosophilids belonging to the tripunctata and virilis-repleta lineages of the Drosophila subgenus, through measures of geographical, abiotic and biotic niche overlap and evaluations regarding the presence of phylogenetic signal or niche identity. We recovered phylogenetic signal attributable to phylogenetic niche conservatism when all species were analyzed together, but not in more restricted groups. Identity tests showed that niche equivalency was seldom rejected for the tripunctata lineage species. So, in general, neither the results for the Drosophila subgenus nor those for the tripunctata lineage support the hypothesis of an adaptive radiation. Notwithstanding, there were also several isolated cases supporting a scenario of ND, and ecological speciation was evident in some of the evaluated sister species pairs.     

DO FRESHWATER FISHES DIVERSIFY FASTER THAN MARINE FISHES? A TEST USING STATE‐DEPENDENT DIVERSIFICATION ANALYSES AND MOLECULAR PHYLOGENETICS OF NEW WORLD SILVERSIDES (ATHERINOPSIDAE)

Freshwater habitats make up only ～0.01% of available aquatic habitat and yet harbor 40% of all fish species, whereas marine habitats comprise >99% of available aquatic habitat and have only 60% of fish species. One possible explanation for this pattern is that diversification rates are higher in freshwater habitats than in marine habitats. We investigated diversification in marine and freshwater lineages in the New World silverside fish clade Menidiinae (Teleostei, Atherinopsidae). Using a time‐calibrated phylogeny and a state‐dependent speciation–extinction framework, we determined the frequency and timing of habitat transitions in Menidiinae and tested for differences in diversification parameters between marine and freshwater lineages. We found that Menidiinae is an ancestrally marine lineage that independently colonized freshwater habitats four times followed by three reversals to the marine environment. Our state‐dependent diversification analyses showed that freshwater lineages have higher speciation and extinction rates than marine lineages. Net diversification rates were higher (but not significant) in freshwater than marine environments. The marine lineage‐through time (LTT) plot shows constant accumulation, suggesting that ecological limits to clade growth have not slowed diversification in marine lineages. Freshwater lineages exhibited an upturn near the recent in their LTT plot, which is consistent with our estimates of high background extinction rates. All sequence data are currently being archived on Genbank and phylogenetic trees archived on Treebase.     

Seed‐dispersal networks respond differently to resource effects in open and forest habitats

While patterns in species diversity have been well studied across large‐scale environmental gradients, little is known about how species’ interaction networks change in response to abiotic and biotic factors across such gradients. Here we studied seed‐dispersal networks on 50 study plots distributed over ten different habitat types on the southern slopes of Mt Kilimanjaro, Tanzania, to disentangle the effects of climate, habitat structure, fruit diversity and fruit availability on different measures of interaction diversity. We used direct observations to record the interactions of frugivorous birds and mammals with fleshy‐fruited plants and recorded climatic conditions, habitat structure, fruit diversity and availability. We found that Shannon interaction diversity (H) increased with fruit diversity and availability, whereas interaction evenness (E_H) and network specialization (H₂) responded differently to changes in fruit availability depending on habitat structure. The direction of the effects of fruit availability on E_H and H₂ differed between open habitats at the mountain base and structurally complex habitats in the forest belt. Our findings illustrate that interaction networks react differently to changes in environmental conditions in different ecosystems. Hence, our findings demonstrate that future projections of network structure and associated ecosystem functions need to account for habitat differences among ecosystems.     

Transgressing Wallace's Line brings hyperdiverse weevils down to earth

Wallace's Line, located in the heart of the Indo-Australian archipelago, has historically been hypothesized to strongly inhibit dispersal. Taxa crossing this barrier are confronted with different biota of Asian or Australian origin, respectively, but the extent to which these conditions have affected the evolution of the colonizing lineages remains largely unknown. We examined the potential correlations of body size, lifestyle and biogeographical distribution in the weevil genus Trigonopterus. These beetles are highly diverse both on foliage and in litter east of Wallace's Line but occur exclusively in leaf litter in the west. Based on a comprehensive, dated phylogeny of 303 species, we inferred nine crossing events of Wallace's Line, all from east to west. Five previously foliage-dwelling lineages changed their lifestyle to leaf litter habitats after crossing this barrier. Our results indicate that dispersal is not more likely in edaphic lineages, but rather that abiotic and/or biotic factors may be responsible for the exclusive leaf litter habitat of Trigonopterus in Sundaland. This includes differences in climate, and the different predatory faunas of Australia-New Guinea, Wallacea and Sundaland. A mimicry complex in New Guinea with Trigonopterus species as presumable model may be of relevance in this context.     

What causes conspecific plant aggregation? Disentangling the role of dispersal,habitat heterogeneity and plant–plant interactions

Spatial patterns of plant species are determined by an array of ecologica factors including biotic and abiotic environmental constraints and intrinsic species traits. Thus, an observed aggregated pattern may be the result of short‐distance dispersal, the presence of habitat heterogeneity, plant–plant interactions or a combination of the above. Here, we studied the spatial pattern of Mediterranean alpine plant Silene ciliata (Caryophyllaceae) in five populations and assessed the contribution of dispersal, habitat heterogeneity and conspecific plant interactions to observed patterns. For this purpose, we used spatial point pattern analysis combined with specific a priori hypotheses linked to spatial pattern creation. The spatial pattern of S. ciliata recruits was not homogeneous and showed small‐scale aggregation. This is consistent with the species’ short‐distance seed dispersal and the heterogeneous distribution of suitable sites for germination and establishment. Furthermore, the spatial pattern of recruits was independent of the spatial pattern of adults. This suggests a low relevance of adult‐recruits interactions in the spatial pattern creation. The difference in aggregation between recruits and adults suggests that once established, recruits are subjected to self‐thinning. However, seedling mortality did not erase the spatial pattern generated by seed dispersal, as S. ciliata adults were still aggregated. Thus, the spatial aggregation of adults is probably due to seed dispersal limitation and the heterogeneous distribution of suitable sites at seedling establishment rather than the presence of positive plant–plant interactions at the adult stage. In fact, a negative density‐dependent effect of the conspecific neighbourhood was found on adult reproductive performance. Overall, results provide empirical evidence of the lack of a simple and direct relationship between the spatial structure of plant populations and the sign of plant–plant interactions and outline the importance of considering dispersal and habitat heterogeneity when performing spatial analysis assessments.     

Cryptic habitats and cryptic diversity: unexpected patterns of connectivity and phylogeographical breaks in a Mediterranean endemic marine cave mysid

The marine cave‐dwelling mysid Hemimysis margalefi is distributed over the whole Mediterranean Sea, which contrasts with the poor dispersal capabilities of this brooding species. In addition, underwater marine caves are a highly fragmented habitat which further promotes strong genetic structuring, therefore providing highly informative data on the levels of marine population connectivity across biogeographical regions. This study investigates how habitat and geography have shaped the connectivity network of this poor disperser over the entire Mediterranean Sea through the use of several mitochondrial and nuclear markers. Five deeply divergent lineages were observed among H. margalefi populations resulting from deep phylogeographical breaks, some dating back to the Oligo‐Miocene. Whether looking at the intralineage or interlineage levels, H. margalefi populations present a high genetic diversity and population structuring. This study suggests that the five distinct lineages observed in H. margalefi actually correspond to as many separate cryptic taxa. The nominal species, H. margalefi sensu stricto, corresponds to the westernmost lineage here surveyed from the Alboran Sea to southeastern Italy. Typical genetic breaks such as the Almeria‐Oran Front or the Siculo‐Tunisian Strait do not appear to be influential on the studied loci in H. margalefi sensu stricto. Instead, population structuring appears more complex and subtle than usually found for model species with a pelagic dispersal phase. The remaining four cryptic taxa are all found in the eastern basin, but incomplete lineage sorting is suspected and speciation might still be in process. Present‐day population structure of the different H. margalefi cryptic species appears to result from past vicariance events started in the Oligo‐Miocene and maintained by present‐day coastal topography, water circulation and habitat fragmentation.     

Diversification across major biogeographic breaks in the African Shining/Square‐tailed Drongos complex (Passeriformes: Dicruridae)

Surprisingly, little is known about the extent of genetic structure within widely distributed and polytypic African species that are not restricted to a particular habitat type. The few studies that have been conducted suggested that speciation among African vertebrates may be intrinsically tied to habitat and the dynamic nature of biome boundaries. In the present study, we assessed the geographic structure of genetic variation across two sister‐species of drongos, the Square‐tailed Drongo (Dicrurus ludwigii) and the Shining Drongo (D. atripennis), that are distributed across multiple sub‐Saharan biogeographic regions and habitat types. Our results indicate that D. ludwigii consists of two strongly divergent lineages, corresponding to an eastern–southern lineage and a central‐western lineage. Furthermore, the central‐western lineage may be more closely related to D. atripennis, a species restricted to the Guineo‐Congolian forest block, and it should therefore be ranked as a separate species from the eastern–southern lineage. Genetic structure is also recovered within the three primary lineages of the D. atripennis–D. ludwigii complex, suggesting that the true species diversity still remains underestimated. Additional sampling and data are required to resolve the taxonomic status of several further populations. Overall, our results suggest the occurrence of complex diversification patterns across habitat types and biogeographic regions in sub‐Saharan Africa birds.     

Higher β‐ and γ‐diversity at species and genetic levels in headwaters than in mid‐order streams in Hydropsyche (Trichoptera)

相似文献   

Niche divergence promotes rapid diversification of East African sky island white‐eyes (Aves: Zosteropidae)

The Eastern Afromontane biodiversity hotspot composed of highly fragmented forested highlands (sky islands) harbours exceptional diversity and endemicity, particularly within birds. To explain their elevated diversity within this region, models founded on niche conservatism have been offered, although detailed phylogeographic studies are limited to a few avian lineages. Here, we focus on the recent songbird genus Zosterops, represented by montane and lowland members, to test the roles of niche conservatism versus niche divergence in the diversification and colonization of East Africa's sky islands. The species‐rich white‐eyes are a typically homogeneous family with an exceptional colonizing ability, but in contrast to their diversity on oceanic islands, continental diversity is considered depauperate and has been largely neglected. Molecular phylogenetic analysis of ~140 taxa reveals extensive polyphyly among different montane populations of Z. poliogastrus. These larger endemic birds are shown to be more closely related to taxa with divergent habitat types, altitudinal distributions and dispersal abilities than they are to populations of restricted endemics that occur in neighbouring montane forest fragments. This repeated transition between lowland and highland habitats over time demonstrate that diversification of the focal group is explained by niche divergence. Our results also highlight an underestimation of diversity compared to morphological studies that has implications for their taxonomy and conservation. Molecular dating suggests that the spatially extensive African radiation arose exceptionally rapidly (1–2.5 Ma) during the fluctuating Plio‐Pleistocene climate, which may have provided the primary driver for lineage diversification.     

Reproductive phenology of Melastomataceae species with contrasting reproductive systems: contemporary and historical drivers

• Flowering and fruiting are key events in the life history of plants, and both are critical to their reproductive success. Besides the role of evolutionary history, plant reproductive phenology is regulated by abiotic factors and shaped by biotic interactions with pollinators and seed dispersers. In Melastomataceae, a dominant Neotropical family, the reproductive systems vary from allogamous with biotic pollination to apomictic, and seed dispersal varies from dry (self‐dispersed) to fleshy (animal‐dispersed) fruits. Such variety in reproductive strategies is likely to affect flowering and fruiting phenologies.
• In this study, we described the reproductive phenology of 81 Melastomataceae species occurring in two biodiversity hotspots: the Atlantic rain forest and the campo rupestre. We aim to disentangle the role of abiotic and biotic factors defining flowering and fruiting times of Melastomataceae species, considering the contrasting breeding and seed dispersal systems, and their evolutionary history.
• In both vegetation types, pollinator‐dependent species had higher flowering seasonality than pollinator‐independent ones. Flowering patterns presented phylogenetic signal regardless of vegetation type. Fruiting of fleshy‐fruited species was seasonal in campo rupestre but not in Atlantic rain forest; the fruiting of dry‐fruited species was also not seasonal in both vegetation types. Fruiting showed a low phylogenetic signal, probably because the influence of environment and dispersal agents on fruiting time is stronger than the phylogenetic affinity.
• Considering these ecophylogenetic patterns, our results indicate that flowering may be shaped by the different reproductive strategies of Melastomataceae lineages, while fruiting patterns may be governed mainly by the seed dispersal strategy and flowering time, with less phylogenetic influence.

     

Ecomorphological variation and sexual dimorphism in a recent radiation of dwarf chameleons (Bradypodion)

Natural selection tends to favour optimal phenotypes either through directional or stabilizing selection; however, phenotypic variation in natural populations is common and arises from a combination of biotic and abiotic interactions. In these instances, rare phenotypes may possess a fitness advantage over the more common phenotypes in particular environments, which can lead to adaptation and ecological speciation. A recently radiated clade of dwarf chameleons (Bradypodion) restricted to southern KwaZulu‐Natal Province, South Africa, is currently comprised of two species (Bradypodion melanocephalum and Bradypodion thamnobates), yet three other phenotypic forms exist, possibly indicating the clade is far more speciose. Very little genetic differentiation exists between these five phenotypic forms; however, all are allopatric in distribution, occupy different habitats and vary in overall size and coloration, which may indicate that these forms are adapting to their local environments and possibly undergoing ecological speciation. To test this, we collected morphometric and habitat data from each form and examined whether ecological relevant morphological differences exist between them that reflect their differential habitat use. Sexual dimorphism was detected in four of the five forms. Yet, the degree and number of dimorphic characters was different between them, with size‐adjusted male‐biased dimorphism being much more pronounced in B. thamnobates. Habitat differences also existed between sexes, with males occupying higher perches in more closed canopy (forested) habitats than females. Clear morphological distinctions were detected between four of the five forms, with the head explaining the vast majority of the variation. Chameleons occupying forested habitats tended to possess proportionally larger heads and feet but shorter limbs than those in open canopy habitats (i.e. grassland). These results show that this species complex of Bradypodion is morphologically variable for traits that are ecologically relevant for chameleons, and that the variation among the five phenotypic forms is associated with habitat type, suggesting that this species complex is in the early stages of ecological speciation. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 109 , 113–130.     

Effects of local biotic neighbors and habitat heterogeneity on seedling survival in a spruce‐fir valley forest,northeastern China

Seedlings are vulnerable to many biotic and abiotic agents, and studying seedling dynamics helps understand mechanisms of species coexistence. In this study, the relative importance of biotic neighbors and habitat heterogeneity to seedling survival was examined by generalized linear mixed models for 33 species in a spruce‐fir valley forest in northeastern China. The results showed that the relative importance of these factors varied with species and functional groups. Conspecific negative density dependence (CNDD) was important to the survival of Abies nephrolepis and Picea koraiensis seedling, whereas phylogenetic negative density dependence (PNDD) was critical to Pinus koraiensis and Betula platyphylla, as well as functional groups of tree, deciduous, and shade‐intolerant seedlings. For shrubs and Acer ukurunduense, habitat heterogeneity was significant. Despite of the significance of CNDD, PNDD, and habitat heterogeneity on seedling survival, large proportions of the total variance were not accounted for by the studied variables, suggesting the needs to examine the influences of other factors such as pests, diseases, herbivores, forest structure, species functional traits, and microclimatic conditions on seedling survival in the future.     

The impact of Quaternary climate oscillations on divergence times and historical population sizes in Thylamys opossums from the Andes

Climate oscillations during the Quaternary altered the distributions of terrestrial animals at a global scale. In mountainous regions, temperature fluctuations may have led to shifts in range size and population size as species tracked their shifting habitats upslope or downslope. This creates the potential for both allopatric speciation and population size fluctuations, as species are either constrained to smaller patches of habitat at higher elevations or able to expand into broader areas at higher latitudes. We considered the impact of climate oscillations on three pairs of marsupial species from the Andes (Thylamys opossums) by inferring divergence times and demographic changes. We compare four different divergence dating approaches, using anywhere from one to 26 loci. Each pair comprises a northern (tropical) lineage and a southern (subtropical to temperate) lineage. We predicted that divergences would have occurred during the last interglacial (LIG) period approximately 125 000 years ago and that population sizes for northern and southern lineages would either contract or expand, respectively. Our results suggest that all three north–south pairs diverged in the late Pleistocene during or slightly after the LIG. The three northern lineages showed no signs of population expansion, whereas two southern lineages exhibited dramatic, recent expansions. We attribute the difference in responses between tropical and subtropical lineages to the availability of ‘montane‐like’ habitats at lower elevations in regions at higher latitudes. We conclude that climate oscillations of the late Quaternary had a powerful impact on the evolutionary history of some of these species, both promoting speciation and leading to significant population size shifts.