An asymmetry in niche conservatism contributes to the latitudinal species diversity gradient in New World vertebrates

The Tropical Niche Conservatism hypothesis is a leading explanation for why biodiversity increases towards the equator. The model suggests that most lineages have tropical origins, with few dispersing into temperate regions. However, biotas are comprised of lineages with differing geographical origins, thus it is unclear whether lineages that originated on different continents will exhibit similar patterns of niche conservatism. Here, we summarised biogeographical patterns of New World vertebrates and compared species diversity patterns between families that originated in North and South America. Overall, families with southern origins exhibit niche conservatism with many lineages restricted to the Neotropics, whereas many northern‐origin families are distributed across the Neotropics and the Nearctic. Consequently, northern lineages have contributed to high tropical biodiversity, but southern lineages have contributed relatively little to temperate biodiversity in North America. The asymmetry in niche conservatism between northern and southern lineages is an important contributor to the biodiversity gradient.     

Rapid expansion and diversification into new niche space by fluvicoline flycatchers

The fluvicoline New World flycatchers (subfamily Fluvicolinae, family Tyrannidae) inhabit a broad range of forest and non‐forest habitats in all parts of the New World. Using a densely sampled phylogeny we depict the diversification and expansion of this group in time and space. We provide evidence that a shift in foraging behaviour allowed the group to rapidly expand in a wide range of tropical and subtropical habitats in South America. The results support that four main clades expanded into and specialized to distinct habitats and climates (closed to open, and warm to cold), respectively, and subsequently underwent vicariant speciation within their respective ecoregions. The group soon reached a significant species diversity over virtually all of South and North America, and with parallel trajectories of speciation slow‐down in all four clades. The genus Muscisaxicola is an exception, as it invaded the most inhospitable and barren environments in the Andes where they underwent rapid diversification in the Plio‐Pleistocene.     

Erratum to: Phylogeny and biogeography of the genus Stevia (Asteraceae: Eupatorieae): an example of diversification in the Asteraceae in the new world

The genus Stevia comprises approximately 200 species, which are distributed in North and South America, and are representative of the species diversity of the Asteraceae in the New World. We reconstructed the phylogenetic relationships using sequences of ITS and cpDNA and estimated the divergence times of the major clade of this genus. Our results suggested that Stevia originated in Mexico 7.0–7.3 million years ago (Mya). Two large clades, one with shrub species and another with herb species, were separated at about 6.6 Mya. The phylogenetic reconstruction suggested that an ancestor of Stevia was a small shrub in temperate pine–oak forests and the evolutionary change from a shrub state to a herb state occurred only once. A Brazilian clade was nested in a Mexican herb clade, and its origin was estimated to be 5.2 Mya, suggesting that the migration from North America to South America occurred after the formation of the Isthmus of Panama. The species diversity in Mexico appears to reflect the habitat diversity within the temperate pine–oak forest zone. The presence of many conspecific diploid–polyploid clades in the phylogenetic tree reflects the high frequency of polyploidization among the perennial Stevia species.

     

Multiple intercontinental dispersals shaped the distribution area of Hordeum (Poaceae)

The grass genus Hordeum (Poaceae, Triticeae), comprising 31 species distributed in temperate and dry regions of the world, was analysed to determine the relative contributions of vicariance and long-distance dispersal to the extant distribution pattern of the genus. Sequences from three nuclear regions (DMC1, EF-G and ITS) were combined and analysed phylogenetically for all diploid (20 species) and two tetraploid Hordeum species and the outgroup Psathyrostachys. Ages of clades within Hordeum were estimated using a penalized likelihood analysis of sequence divergence. The sequence data resulted in an almost fully resolved phylogenetic tree that allowed the reconstruction of intrageneric migration routes. Hordeum evolved c. 12 million years ago in South-west Asia and spread into Europe and Central Asia. The colonization of the New World and South Africa involved at least six intercontinental exchanges during the last 4 million years (twice Eurasia-North America, North America-South America, twice South America-North America and Europe-South Africa). Repeated long-distance dispersal between the northern and southern hemisphere were important colonization mechanisms in Hordeum.     

The profound influence of the Late Pliocene Panamanian uplift on the exchange,diversification, and distribution of New World birds

Separated throughout most of the Cenozoic era, North and South America were joined during the mid‐Pliocene when the uplift of Panama formed a land bridge between these two continents. The fossil record indicates that this connection allowed an unprecedented degree of inter‐continental exchange to occur between unique, previously isolated biotic assemblages, a phenomenon now recognized as the “Great American Biotic Interchange”. However, a relatively poor avian fossil record has prevented our understanding the role of the land bridge in shaping New World avian communities. To address the question of avian participation in the GABI, we compiled 64 avian phylogenetic studies and applied a relaxed molecular clock to estimate the timing of trans‐isthmus diversification events. Here, we show that a significant pulse of avian interchange occurred in concert with the isthmus uplift. The avian exchange was temporally consistent with the well understood mammalian interchange, despite the presumed greater vagility of birds. Birds inhabiting a variety of habitats and elevational zones responded to the newly available corridor. Within the tropics, exchange was equal in both directions although between extratropical and tropical regions it was not. Avian lineages with Nearctic origins have repeatedly invaded the tropics and radiated throughout South America; whereas, lineages with South American tropical origins remain largely restricted to the confines of the Neotropical region. This previously unrecognized pattern of asymmetric niche conservatism may represent an important and underappreciated contributor to the latitude diversity gradient.     

Diversification of Lupinus (Leguminosae) in the western New World: derived evolution of perennial life history and colonization of montane habitats

Previous phylogenetic studies of Lupinus (Leguminosae) based on nuclear DNA have shown that the western New World taxa form a monophyletic group representing the majority of species in the genus, with evidence for high rates of recent diversification in South America following final uplift of the Andes 2–4 million years ago (Mya). For this study, three regions of rapidly evolving non-coding chloroplast DNA (trnL intron, trnS–trnG, and trnT–trnL) were examined to estimate the timing and rates of diversification in the western New World, and to infer ancestral states for geographic range, life history, and maximum elevation. The western New World species (5.0–9.3 Mya, 0.6–1.1 spp./My) comprise a basally branching assemblage of annual plants endemic to the lower elevations of western North America, from which two species-rich clades are recently derived: (i) the western North American perennials from the Rocky Mountains, Great Basin, and Pacific Slope (0.7–2.1 Mya, 2.0–5.9 spp./My) and (ii) the predominantly perennial species from the Andes Mountains of South America and highlands of Mexico (0.8–3.4 Mya, 1.4–5.7 spp./My). Bayesian posterior predictive tests for association between life history and maximum elevation demonstrate that perennials are positively correlated with higher elevations. These results are consistent with a series of one or more recent radiations in the western New World, and indicate that rapid diversification of Lupinus coincides with the derived evolution of perennial life history, colonization of montane habitats, and range expansion from North America to South America.     

Quantifying the Extent of North American Mammal Extinction Relative to the Pre-Anthropogenic Baseline

Earth has experienced five major extinction events in the past 450 million years. Many scientists suggest we are now witnessing a sixth, driven by human impacts. However, it has been difficult to quantify the real extent of the current extinction episode, either for a given taxonomic group at the continental scale or for the worldwide biota, largely because comparisons of pre-anthropogenic and anthropogenic biodiversity baselines have been unavailable. Here, we compute those baselines for mammals of temperate North America, using a sampling-standardized rich fossil record to reconstruct species-area relationships for a series of time slices ranging from 30 million to 500 years ago. We show that shortly after humans first arrived in North America, mammalian diversity dropped to become at least 15%–42% too low compared to the “normal” diversity baseline that had existed for millions of years. While the Holocene reduction in North American mammal diversity has long been recognized qualitatively, our results provide a quantitative measure that clarifies how significant the diversity reduction actually was. If mass extinctions are defined as loss of at least 75% of species on a global scale, our data suggest that North American mammals had already progressed one-fifth to more than halfway (depending on biogeographic province) towards that benchmark, even before industrialized society began to affect them. Data currently are not available to make similar quantitative estimates for other continents, but qualitative declines in Holocene mammal diversity are also widely recognized in South America, Eurasia, and Australia. Extending our methodology to mammals in these areas, as well as to other taxa where possible, would provide a reasonable way to assess the magnitude of global extinction, the biodiversity impact of extinctions of currently threatened species, and the efficacy of conservation efforts into the future.     

Origins of New World monkeys

Fossil ceboid evidence is reviewed with reference to the origins and affinities of the New World monkeys. This evidence indicates that the ceboids evolved from a North American primate of omomyid-like form. The events of continental drift apparently had little to do with the origin and dispersion of the New World monkeys and direct relationships to the Old World monkeys are not indicated. Three of the five extant New World monkey subfamilies are represented in late Miocene deposits of South America and it appears that evolutionary events leading to extant Ceboidea occurred within the South American continent.     

Phylogeny, biogeography, and host-plant association in the subfamily Apaturinae (Insecta: Lepidoptera: Nymphalidae) inferred from eight nuclear and seven mitochondrial genes

The subfamily Apaturinae consists of 20 genera and shows disjunct distributions and unique host-plant associations. Most genera of this subfamily are distributed in Eurasia South-East Asia and Africa, whereas the genera Doxocopa and Asterocampa are distributed mainly in South America and North America, respectively. Although the Apaturinae larvae mainly feed on the Cannabaceae, those of the genus Apatura are associated with Salix and Populus (Salicaceae), which are distantly related to the Cannabaceae. Here, we infer the phylogeny of Apaturinae and reconstruct the history of host shifting and of colonization in the New World. We analyzed 9761 bp of nuclear and mitochondrial DNA sequence data, including the genes encoding EF1a, Wg, ArgK, CAD, GAPDH, IDH, MDH, RpS5, COI, COII, ATPase8, ATPase6, COIII, ND3, and ND5 for 12 apaturine genera. We also inferred the phylogeny with six additional genera using mitochondrial sequence data alone. Within the Apaturinae, two major clades are recovered in all the datasets. These clades separate the New World genera, Doxocopa and Asterocampa, indicating that dispersal to the New World occurred at least twice. According to our divergence time estimates, these genera originated during the Early Oligocene to the Early Miocene, implying that they migrated across the Bering Land Bridge rather than the Atlantic Land Bridge. The temporal estimates also show that host shifting to Salix or Populus in Apatura occurred more than 15 million years after the divergence of their host plants. Our phylogenetic results are inconsistent with the previously accepted apaturine genus groups and indicate that their higher classification should be reconsidered.     

EVOLUTIONARY AND BIOGEOGRAPHIC ORIGINS OF HIGH TROPICAL DIVERSITY IN OLD WORLD FROGS (RANIDAE)

Differences in species richness between regions are ultimately explained by patterns of speciation, extinction, and biogeographic dispersal. Yet, few studies have considered the role of all three processes in generating the high biodiversity of tropical regions. A recent study of a speciose group of predominately New World frogs (Hylidae) showed that their low diversity in temperate regions was associated with relatively recent colonization of these regions, rather than latitudinal differences in diversification rates (rates of speciation–extinction). Here, we perform parallel analyses on the most species-rich group of Old World frogs (Ranidae; ∼1300 species) to determine if similar processes drive the latitudinal diversity gradient. We estimate a time-calibrated phylogeny for 390 ranid species and use this phylogeny to analyze patterns of biogeography and diversification rates. As in hylids, we find a strong relationship between the timing of colonization of each region and its current diversity, with recent colonization of temperate regions from tropical regions. Diversification rates are similar in tropical and temperate clades, suggesting that neither accelerated tropical speciation rates nor greater temperate extinction rates explain high tropical diversity in this group. Instead, these results show the importance of historical biogeography in explaining high species richness in both the New World and Old World tropics.     

Perspectives on Palaearctic and Nearctic bird migration; comparisons and overview of life-history and ecology of migrant passerines

In this paper we compare ecological attributes of tropical migrant passerines from the Nearctic and western Palaearctic, focusing particularly on habitat association patterns during both breeding and wintering seasons. Three regions were compared: Europe, western and eastern North America. Breeding bird census data from 32 studies (each including at least four stages of forest succession) were used to assess the association patterns of breeding habitats among tropical migrants. For each species we calculated an index of habitat diversity and habitat preference.
Tropical migrants preferred earlier successional stages than other birds in Europe. The opposite was true in eastern North America. In eastern North America, tropical migrants tended to be associated with a smaller range of serai stages than other passerine species. In their winter quarters, Palaearctic migrants live primarily in open habitats, such as savannas, whereas eastern Nearctic migrants make more frequent use of evergreen forests. Migrants from western North America show the greatest match between breeding and wintering habitats.
We relate the results to the taxonomy and probable history of contemporary avifaunas and vegetation formations of the Old and New World. Taxonomically, tropical migrants from different parts of the Holarctic are less closely related to each other than residents and short-distance migrants. Tropical and temperate avifaunas are more closely related to each other in the New World than in the Old World. Conservation implications of the between-continent differences are briefly discussed.     

Phylogenetic relationships of mormyrid electric fishes (Mormyridae; Teleostei) inferred from cytochrome b sequences

The nasute termite genus Nasutitermes is widely distributed over all tropical regions. The phylogenetic relationships among 17 Nasutitermes species from the Pacific tropics were inferred from sequences of mitochondrial cytochrome oxidase II and 16S ribosomal RNA genes. Several methods of analysis yielded phylogenetic trees showing almost the same topology and in good agreement with reconstructions based on morphological or behavioral characters. Neotropical and Australian species came out as separate, apical clades. Asian species split between an apical branch, appearing as sister group to the neotropical clade, and basal taxa. New Guinean species were spread among several clades, suggesting a derivation from multiple origins. A well-supported clade includes the neotropical, Australian, and New Guinean species, with the southeast Asian N. takasagoensis and N. matangensis. It excludes the Asian species N. regularis, N. parvonasutus, and N. longinasus, which might deserve to be removed from Nasutitermes, as well as the long-legged Asian genera Hospitalitermes and Longipeditermes. A Gondwanan origin is proposed for the former clade, although an Old World origin of Nasutitermes followed by dispersal to Australia and South America cannot be excluded.     

Evolution of a triplet repeat in a conifer.

The opportunity to trace the evolution of a triplet repeat is rare, especially for seed-plant lineages with a well-defined fossil record. Microsatellite PtTX2133 sequences from 18 species in 2 conifer genera were used to calibrate the birth of a CAGn repeat, from its protomicrosatellite origins to its repeat expansion. Birth occurred in the hard-pine genome ~ 136 million years ago, or 14 million generations ago, then expanded as a polymorphic triplet repeat 136-100 million years before a major North American vicariance event. Calibration of the triplet-repeat birth and expansion is supported by the shared allelic lineages among Old and New World hard pines and the shared alleles solely among North American diploxylon or hard pines. Five CAGn repeat units appeared to be the expansion threshold for Old and New World diploxylon pines. Haploxylon pine species worldwide did not undergo birth and repeat expansion, remaining monomorphic, with a single imperfect 198-bp allele. A sister genus, Picea, had only a region of cryptic simplicity, preceding a proto-microsatellite region. The polymorphic triplet repeat in hard pines is older than some long-lived microsatellites reported for reptiles, yet younger than those reported for insects. Some cautionary points are raised about phylogenetic applications for this long-lived microsatellite.     

Phylogeny, biogeography, and rates of diversification of New World Astragalus (Leguminosae) with an emphasis on South American radiations

This study uses phylogenetic relationships of New World representatives of the species-rich genus Astragalus (Leguminosae; Papilionoideae) to follow up on recent evidence pointing to rapid and recent plant diversification patterns in the Andes. Bayesian and maximum likelihood phylogenetic analyses were done using nuclear rDNA ITS and chloroplast spacers trnD-trnT and trnfM-trnS1, either separately or in combination. The effect of using partitioned vs. nonpartitioned analyses in a Bayesian approach was evaluated. Highest resolution was obtained when the data were combined in partitioned or nonpartitioned Bayesian analyses. All phylogenies support two clades of South American species nested within the North American species, implying two separate invasions from North to South America. These two clades correspond to the original morphological classification of Johnston (1947 Journal of the Arnold Arboretum 28: 336-409). The mean ages of the South American clades were very recent but still significantly different (1.89 and 0.98 Ma). Upper and lower bounds on rates of diversification varied between 2.01 and 0.65 species/Ma for the older clade and 2.06 and 1.24 species/Ma for the younger clade. Even the lower bounds are still very high, reasserting Neo-Astragalus in the growing list of recent rapid radiations of plants, especially in areas with a high physiographic diversity, such as the Andes.     

The Central American land bridge as an engine of diversification in New World doves

Aim The closure of the Central American land‐bridge connection between North and South America 3.5 million years ago was a major biogeographic event that allowed considerable interchange of the previously isolated faunas of these continents. However, the role that this connection may have had in diversification of North and South American faunas is less well understood. The goal of this study was to evaluate the potential role of the formation of this land connection in generating diversity, through repeated rare dispersal events followed by isolation. Location North and South America. Methods We evaluated the role of the Central American land‐bridge connection in avian diversification using a molecular phylogeny based on four gene regions for mid‐sized New World doves. Diversification events were dated using a Bayesian relaxed clock analysis and internal calibration points for endemic island taxa with known island ages. Results The reconstructed phylogenetic tree was well supported and recovered monophyly of the genera Leptotila and Zenaida, but the quail‐doves (Geotrygon) were paraphyletic, falling into three separate lineages. The phylogeny indicated at least nine dispersal‐driven divergence events between North and South America. There were also five dispersal events in the recent past that have not yet led to differentiation of taxa (polymorphic taxa). Main conclusions Most of these dispersal‐driven diversification events occurred at the time of or after the formation of the Central American land bridge, indicating that this land connection played a role in facilitating divergence via dispersal of doves between continents.     

Marsupial relationships and a timeline for marsupial radiation in South Gondwana

Recent marsupials include about 280 species divided into 18 families and seven orders. Approximately 200 species live in Australia/New Guinea. The remaining species inhabit South America with some of these secondarily ranging into North America. In this study, we examine marsupial relationships and estimate their divergences times using complete mitochondrial (mt) genomes. The sampling, which includes nine new mtDNAs and a total number of 19 marsupial genomes, encompasses all extant orders and 14 families. The analysis identified a basal split between Didelphimorphia and remaining orders about 69 million years before present (MYBP), while other ordinal divergences were placed in Tertiary times. The monotypic South American order Microbiotheria (Dromiciops gliroides, Monito del Monte) was solidly nested among its Australian counterparts. The results suggest that marsupials colonized Australia twice from Antarctica/South America and that the divergence between Microbiotheria and its Australian relatives coincided with the geological separation of Antarctica and Australia. Within Australia itself, several of the deepest divergences were estimated to have taken place close to the Eocene/Oligocene transition.     

Phylogenetic relationships and evolution in Chrysosplenium (Saxifragaceae) based on matK sequence data

Chrysosplenium (Saxifragaceae) consists of 57 species widely distributed in temperate and arctic regions of the Northern Hemisphere, with two species restricted to the southern part of South America. Species relationships within the genus are highly problematic. The genus has traditionally been divided into two groups, sometimes recognized as sections (Oppositifolia and Alternifolia), based on leaf arrangement, or, alternatively, into 17 series. Based on morphological features, Hara suggested that the genus originated in South America and then subsequently migrated to the Northern Hemisphere. We conducted phylogenetic analyses of DNA sequences of the chloroplast gene matK for species of Chrysosplenium to elucidate relationships, test Hara's biogeographic hypothesis for the genus, and examine chromosomal and gynoecial diversification. These analyses revealed that both sections Oppositifolia and Alternifolia are monophyletic and form two large sister clades. Hence, leaf arrangement is a good indicator of relationships within this genus. Hara's series Pilosa and Macrostemon are each also monophyletic; however, series Oppositifolia, Alternifolia, and Nepalensia are clearly not monophyletic. MacClade reconstructions suggest that the genus arose in Eastern Asia, rather than in South America, with several independent migration events from Asia to the New World. In one well-defined subclade, species from eastern and western North America form a discrete clade, with Old World species as their sister group, suggesting that the eastern and western North American taxa diverged following migration to that continent. The South American species forms a clade with species from eastern Asia; this disjunction may be the result of ancient long-distance dispersal. Character mapping demonstrated that gynoecial diversification is dynamic, with reversals from inferior to half-inferior ovaries, as well as to ovaries that appear superior. Chromosomal evolution also appears to be labile with several independent origins of n = 12 (from an original number of n = 11) and multiple episodes of aneuploidy.     

Melastomeae come full circle: biogeographic reconstruction and molecular clock dating

Rhexia, with 11 species in the Coastal Plain province of North America, is the only temperate zone endemic of the tropical eudicot family Melastomataceae. It is a member of the only pantropical tribe of that family, Melastomeae. Based on the chloroplast gene ndhF, we use a fossil-calibrated molecular clock to address the question of the geographic origin and age of Rhexia. Sequences from 37 species in 21 genera representing the tribe's geographical range were analyzed together with five outgroups. To obtain better clade support, another chloroplast region, the rpl16 intron, was added for 24 of the species. Parsimony analysis of the combined data and maximum-likelihood analysis of ndhF alone indicate that the deepest split is between Rhexia plus its sister group, a small Central American genus, and all other Melastomeae. Old World Melastomeae are monophyletic and nested within New World Melastomeae. Although likelihood-ratio tests of clock and nonclock substitution models for the full or moderately pruned datasets rejected the clock, these models yielded identical topologies (for 30 taxa) with few significantly different branch lengths as assessed by a Student's t-test. Age estimates obtained were 22 million years ago (Mya) for the divergence of Rhexia from its sister group, 12 Mya for the dispersal of Melastomeae from the New World to West Africa, and 1 Mya for the diversification of Melastoma in Southeast Asia. The only other genus of Melastomeae to have reached Southeast Asia from Africa or Madagascar is Osbeckia. The age and geographic distribution of fossils, which come from Miocene sites throughout Eurasia, suggest that Melastomeae once ranged from Eurasia across Beringia to North America from whence they reached South America and subsequently Africa and Southeast Asia. Climate deterioration led to their extinction in the Northern Hemisphere, with Rhexia possibly surviving in Coastal Plain refugia.     

The genus Artemisia (Asteraceae: Anthemideae) at a continental crossroads: molecular insights into migrations, disjunctions, and reticulations among Old and New World species from a Beringian perspective

Artemisia is the largest genus (ca. 350-500+ spp.) in the tribe Anthemideae and is composed of ecologically, morphologically, and chemically diverse species that are found primarily throughout the Northern Hemisphere. Two major centers of diversity for the genus are located in Eurasia and western North America, but phytogeographic links connecting these two regions are observed all across the North Pacific Rim and adjacent areas in the Arctic, including many islands and archipelagos. Previous phylogenetic studies have helped to clarify major lineages and identify likely sister relationships, but many questions remain unanswered regarding the relationships and migration history of New and Old World species. Here we investigate the phylogenetics of Artemisia within a biogeographic context centered in the Beringian Region and offer new hypotheses concerning species relationships, migration history, and the likely role of reticulate evolution in the genus. Our sampling included many new taxa and emphasized multiple accessions of widespread species, species from proposed refugia, and species with disjunct/vicariant distributions. The ITS phylogeny contained 173 accessions (94 new and 79 from GenBank) and indicated that Artemisia is paraphyletic by the exclusion of several small Asian genera and the North American genus Sphaeromeria. Following a survey of thirteen chloroplast loci, phylogenies based on two plastid markers (psbA-trnH and rpl32-trnL spacers) were constructed with a reduced data set, and though largely consistent with the ITS topology, revealed several cases of possible introgression among New World and Beringian species. Our analysis reveals that North American Artemisia species have multiple origins, and that western North America has served as a source for some colonizing elements in eastern Asia and South America.     

Phylogeny and biogeography of the carnivorous plant family Sarraceniaceae

The carnivorous plant family Sarraceniaceae comprises three genera of wetland-inhabiting pitcher plants: Darlingtonia in the northwestern United States, Sarracenia in eastern North America, and Heliamphora in northern South America. Hypotheses concerning the biogeographic history leading to this unusual disjunct distribution are controversial, in part because genus- and species-level phylogenies have not been clearly resolved. Here, we present a robust, species-rich phylogeny of Sarraceniaceae based on seven mitochondrial, nuclear, and plastid loci, which we use to illuminate this family's phylogenetic and biogeographic history. The family and genera are monophyletic: Darlingtonia is sister to a clade consisting of Heliamphora+Sarracenia. Within Sarracenia, two clades were strongly supported: one consisting of S. purpurea, its subspecies, and S. rosea; the other consisting of nine species endemic to the southeastern United States. Divergence time estimates revealed that stem group Sarraceniaceae likely originated in South America 44-53 million years ago (Mya) (highest posterior density [HPD] estimate = 47 Mya). By 25-44 (HPD = 35) Mya, crown-group Sarraceniaceae appears to have been widespread across North and South America, and Darlingtonia (western North America) had diverged from Heliamphora+Sarracenia (eastern North America+South America). This disjunction and apparent range contraction is consistent with late Eocene cooling and aridification, which may have severed the continuity of Sarraceniaceae across much of North America. Sarracenia and Heliamphora subsequently diverged in the late Oligocene, 14-32 (HPD = 23) Mya, perhaps when direct overland continuity between North and South America became reduced. Initial diversification of South American Heliamphora began at least 8 Mya, but diversification of Sarracenia was more recent (2-7, HPD = 4 Mya); the bulk of southeastern United States Sarracenia originated co-incident with Pleistocene glaciation, <3 Mya. Overall, these results suggest climatic change at different temporal and spatial scales in part shaped the distribution and diversity of this carnivorous plant clade.