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Interspecific trait divergence may reflect adaptation and reproductive isolation, particularly after the rapid differentiation that may follow the colonization of new environments. Although new lineages are generally expected to be morphologically and ecologically similar to their ancestors, environmental forces can also drive adaptive differentiation along specific phenotypic axes. We used climate niche models and comparative analyses based on a previously inferred phylogeny to examine the history of ecological and morphological divergence of Neotropical firs (Abies Mill., Pinaceae), a group of conifers that have recently colonized and diversified in the mountains of Mexico and northern Central America. We inferred past secondary contact zones by comparing current and past climate niche projections and looked for evidence of recent interspecific gene flow using genomic data. Neotropical firs have similar niches to each other and show a strong phylogenetic signal for most evaluated morphological traits. Analyses based on individual variables suggested a random walk model of differentiation. However, early adaptation to tropical conditions is inferred in the ancestor of the southernmost firs, as all modern southern taxa are differentiated climatically from Abies concolor, the northernmost species. In addition, observed autapomorphic traits for soil properties and the number of resin ducts in needles are consistent with possible species‐specific adaptations. Thus, a combination of nonadaptive and adaptive processes along different phenotypic axes, some related to the environment, likely operated after the southward migration of this plant lineage from North America and its subsequent radiation in the Neotropics. [ABSTRACT FROM AUTHOR]

We used nuclear genomic data and statistical models to evaluate the ecological and evolutionary processes shaping spatial variation in species richness in Calochortus (Liliaceae, 74 spp.). Calochortus occupies diverse habitats in the western United States and Mexico and has a center of diversity in the California Floristic Province, marked by multiple orogenies, winter rainfall, and highly divergent climates and substrates (including serpentine). We used sequences of 294 low-copy nuclear loci to produce a time-calibrated phylogeny, estimate historical biogeography, and test hypotheses regarding drivers of present-day spatial patterns in species number. Speciation and species coexistence require reproductive isolation and ecological divergence, so we examined the roles of chromosome number, environmental heterogeneity, and migration in shaping local species richness. Six major clades--inhabiting different geographic/climatic areas, and often marked by different base chromosome numbers (n = 6 to 10)--began diverging from each other ~10.3 Mya. As predicted, local species number increased significantly with local heterogeneity in chromosome number, elevation, soil characteristics, and serpentine presence. Species richness is greatest in the Transverse/Peninsular Ranges where clades with different chromosome numbers overlap, topographic complexity provides diverse conditions over short distances, and several physiographic provinces meet allowing immigration by several clades. Recently diverged sister-species pairs generally have peri-patric distributions, and maximum geographic overlap between species increases over the first million years since divergence, suggesting that chromosomal evolution, genetic divergence leading to gametic isolation or hybrid inviability/sterility, and/or ecological divergence over small spatial scales may permit species co-occurrence. [ABSTRACT FROM AUTHOR]

Secondary contact of recently diverged species may have several outcomes, ranging from rampant hybridization to reinforced reproductive isolation. In plants, selfing tolerance and disjunct reproductive phenology may lead to reproductive isolation at contact zones. However, they may also evolve under both allopatric or parapatric frameworks and originate from adaptive and/or neutral forces. Inferring the historical demography of diverging taxa is thus a crucial step to identify factors that may have led to putative reproductive isolation. We explored various competing demographypotheses to account for the rapid divergence of a fir species complex (Abies flinckii–A. religiosa) distributed in "sky‐islands" across central Mexico (i.e., along the Trans‐Mexican Volcanic Belt; TMVB). Despite co‐occurring in two independent sympatric regions (west and centre), these taxa rarely interbreed because of disjunct reproductive phenologies. We genotyped 1147 single nucleotide polymorphisms, generated by GBS (genotyping by sequencing), across 23 populations, and compared multiple scenarios based on the geological history of the TMVB. The best‐fitting model revealed one of the most rapid and complete speciation cases for a conifer species‐pair, dating back to ~1.2 million years ago. Coupled with the lack of support for stepwise colonization, our coalescent inferences point to an early cessation of interspecific gene flow under parapatric speciation; ancestral gene flow during divergence was asymmetrical (mostly from western firs into A. religiosa) and exclusive to the most ancient (i.e., central) contact zone. Factors promoting rapid reproductive isolation should be explored in other slowly evolving species complexes as they may account for the large tropical and subtropical diversity. [ABSTRACT FROM AUTHOR]

Endosymbiont‐induced cytoplasmic incompatibility (CI) may play an important role in arthropod speciation. However, whether CI consistently becomes associated or coupled with other host‐related forms of reproductive isolation (RI) to impede the transfer of endosymbionts between hybridizing populations and further the divergence process remains an open question. Here, we show that varying degrees of pre‐ and postmating RI exist among allopatric populations of two interbreeding cherry‐infesting tephritid fruit flies (Rhagoletis cingulata and R. indifferens) across North America. These flies display allochronic and sexual isolation among populations, as well as unidirectional reductions in egg hatch in hybrid crosses involving southwestern USA males. All populations are infected by a Wolbachia strain, wCin2, whereas a second strain, wCin3, only co‐infects flies from the southwest USA and Mexico. Strain wCin3 is associated with a unique mitochondrial DNA haplotype and unidirectional postmating RI, implicating the strain as the cause of CI. When coupled with nonendosymbiont RI barriers, we estimate the strength of CI associated with wCin3 would not prevent the strain from introgressing from infected southwestern to uninfected populations elsewhere in the USA if populations were to come into secondary contact and hybridize. In contrast, cytoplasmic–nuclear coupling may impede the transfer of wCin3 if Mexican and USA populations were to come into contact. We discuss our results in the context of the general paucity of examples demonstrating stable Wolbachia hybrid zones and whether the spread of Wolbachia among taxa can be constrained in natural hybrid zones long enough for the endosymbiont to participate in speciation. [ABSTRACT FROM AUTHOR]

Mazama temama is the smallest red deer in Central America. It was one of the first species described for the genus, and until the end of the last century many authors considered it as a subspecies of Mazama americana due to morphological similarities. Cytogenetic studies of animals in captivity have shown different karyotypes that led to its recognition as a unique species, and phylogenetic studies sustained the monophyly of the species, with some inconsistencies due to its wide geographical distribution. The objectives of the study were to characterize a topotype of Veracruz and three other specimens from a Campeche locality, to complement the description of M. temama and to propose a neotype for the species. We described this species morphologically (cranial measurements, skin color, and body biometry), and obtained karyorypes from wild animals with known origins for cytogenetic analyses (C band, G band, Ag-NOR, and Giemsa staining). We also performed phylogenetic analyses of Cytb, D-loop, COI, and ND5 mitochondrial genes. The morphometric results separated M. temama from M. americana but not from the other small Mazama species. The phylogenetic trees of mitochondrial genes Cytb, COI, and ND5 corroborated the monophyly of the species with 100% of posterior probability. The topotype's karyotype is significantly different from the one previously described for the species, and the other specimens from Campeche have karyotype variants whose chromosomal rearrangements are possibly the beginning of a reproductive isolation mechanism. We discussed the possibility to have more than one species of red brocket deer in Mexico and Central America. [ABSTRACT FROM AUTHOR]

Leaf‐toed geckos (Phyllodactylus) exhibit much cryptic diversity, at least in North America. However, the origins of Central American taxa and their relationships with North American congeners remain unknown. The P. tuberculosus species complex is ideal for evolutionary and biogeographic studies because its geographic distribution extends from northern Mexico to Costa Rica. We analyse ~2,500 nuclear loci obtained by the GBS genomic technique to test hypotheses of genetic isolation among taxa and estimate times of divergence using a relaxed molecular clock model, which constitutes the first hypothesis for the diversification of North and Central American phyllodactylids. Phylogenetic analysis recovers three main clades within polyphyletic P. tuberculosus: tuberculosus, magnus and saxatilis. ABBA‐BABA tests show moderate to low levels of gene flow within the latter two clades and yet genetic isolation in Central American lineages. The relaxed molecular clock model dates the age of the MRCA between the Central American and North American lineages to the beginning of the Paleocene (65 mya), suggesting an ancestral distribution in the proto‐Mexican region and the Chortis Block. [ABSTRACT FROM AUTHOR]

We describe a new species of leaf-toed gecko of the genus Phyllodactylus from María Cleofas Island, the smallest island of Tres Marías Archipelago, Nayarit, México. Genomic, phylogenomic, and morphological evidence support that the new species presents a unique combination of diagnostic characters. Morphologically, the new species has a high number of tubercles, head to tail (mean 47), longitudinal ventral scales (mean 61), and third labial-snout scales (mean 26). Gene flow tests revealed the genetic isolation of insular populations from mainland counterparts. In addition, we confirmed the non-monophyly of P. homolepidurus and P. nolascoensis, and we show that the taxon P. t. saxatilis is a complex; therefore, we propose taxonomic changes within the saxatilis clade. The discovery of this new insular endemic species highlights the urgency of continued exploration of the biological diversity of island faunas of Mexico. [ABSTRACT FROM AUTHOR]

Firewood and charcoal are used on a daily basis both in rural areas and in cities. This type of energy is produced by one of the most ancient traditional methods, known as coppice, which harvest tree sprouts. There is controversy about its effects on forests: it preserves populations and tree cover of species used, but reduces density, inhibits sexual reproduction and generates genetic erosion. We inquired if it was possible to identify a loss of genetic diversity in oak populations traditionally used for charcoal by the Zongolica Nahuas in Veracruz state, Mexico. We studied populations of Quercus laurina, Quercus calophylla and Quercus rugosa in three different altitudes. Molecular analysis with eight nuclear codominant microsatellites was performed to determine the diversity, structure and gene flow of these species. Results for Q. laurina were Na = 8.458, I = 1.766, Ho = 0.679, polymorphism = 100%, Fis = 0.079, with intraindividual variation of 81.55%. For Q. calophylla: Na = 7.250, I = 1.563, Ho = 0.646, polymorphism = 91.67%, Fis = 0.083, with intraindividual variation of 83.80%. For Q. rugosa: Na = 6.958, I = 1.510, Ho = 0.574, polymorphism = 91.67%, Fis = 0.204, with intraindividual variation of 81.99%; this species shows signals of an early genetic isolation process. Our findings indicate that Quercus genetic diversity for the three species is high and comparable with oak species in Mexico and worldwide. We conclude that at the present, coppice is preserving a historical diversity in adult trees kept alive through sprouting. Nonetheless, problems with coppice systems elsewhere, unregulated harvesting and expansion of pine plantation in the region suggest that further studies, hand in hand with a landscape management approach that improve charcoal and firewood production, may be valuable for Sierra de Zongolica genetic biodiversity conservation. [ABSTRACT FROM AUTHOR]

Premise: Past climate fluctuations during the Holocene and Pleistocene shaped the distribution of several plant species in temperate areas over the world. Wild maize, commonly known as teosinte, is a good system to evaluate the effects of historical climate fluctuations on genetic diversity due to its wide distribution in Mexico with contrasting environmental conditions. We explored the influence of contemporary factors and historical environmental shifts on genetic diversity, including present and three historical periods using neutral markers. Methods: We used 22 nuclear microsatellite loci to examine the genetic diversity of 14 populations of Zea mays subsp. parviglumis and 15 populations of Zea mays subsp. mexicana (527 individuals total). We implemented genetic structure analyses to evaluate genetic differentiation between and within subspecies. We applied coalescent‐based demographic analysis and species distribution modeling to evaluate the effects of historical environmental shifts. Results: We found 355 alleles in total for the two subspecies and variable levels of diversity in each (Z. mays subsp. parviglumis expected heterozygosity HE = 0.3646–0.7699; Z. mays subsp. mexicana HE = 0.5885–0.7671). We detected significant genetic structure among populations (DEST = 0.4332) with significant heterozygote deficiency (FIS = 0.1796), and variable selfing rates (sg2 = 0.0–0.3090). The Bayesian assignment analysis differentiated four genetic groups. Demographic and species distribution modeling analysis suggested that environmental shifts were influential in the amount of genetic diversity. Conclusions: Our analyses suggest that the current genetic diversity in teosinte is shaped by factors such as local adaptation and genetic isolation, along with historical environmental fluctuations. [ABSTRACT FROM AUTHOR]

Populations of the marine benthic red macroalgae Hypnea musciformis and Hypnea pseudomusciformis along the Atlantic and Pacific Oceans were tested for phylogeographic structure using the DNA barcode COI-5P combined with rbcL for the construction of the phylogenetic tree. Strong patterns of genetic structure were detected across 210 COI-5P DNA sequences, and 37 COI-5P haplotypes were found, using multiple statistical approaches. Hypnea musciformis was found in the Northeast and Northwest Atlantic, the Mediterrean Sea, Namibia, and along the Pacific coast of Mexico. Two new putative species were detected, Hypnea sp. 1 in the Caribbean Sea and Hypnea sp. 2 in the Dominican Republic. Three distinct marine phylogeographic provinces were recognized in the Southern Hemisphere for H. pseudomusciformis: Uruguay, South-Southeast Brazil, and Northeast Brazil. The degree of genetic isolation and distinctness among these provinces varied considerably. The Uruguay province was the most genetically distinct, as characterized by four unique haplotypes not shared with any of the Brazilian populations. Statistically significant results support both, isolation by distance and isolation by environment hypotheses, explaining the formation and mantainance of phylogeographic structuring along the Uruguay-Brazil coast. Geographic, taxonomic and molecular marker concordances were found between our H. pseudomusciformis results and published studies. Furthermore, our data indicate that the Hawaiian introduced populations of H. musciformis contain Hypnea sp. 1 haplotypes, the current known distribution of which is restricted to the Caribbean. [ABSTRACT FROM AUTHOR]

Geography is often a key factor facilitating population divergence and speciation. In this regard, the geographic distributions of flies in the genus Rhagoletis ( Diptera: Tephritidae) in temperate North America have been affected by cycles of Pleistocene glaciation and interglacial periods. Fluctuations in climatic conditions may have had their most dramatic effects on geographically isolating Rhagoletis flies in the central highland region of Mexico. During past periods of allopatry, a degree of post-zygotic reproductive isolation appears to have evolved between hawthorn-infesting populations of Rhagoletis pomonella ( Walsh) in the central Eje Volcanico Trans Mexicano ( EVTM) and those from the Sierra Madre Oriental Mountains ( SMO) of Mexico, as well as hawthorn flies from the eastern USA. Here, we investigate the generality of this finding in the genus Rhagoletis by testing for reproductive isolation among populations of Rhagoletis cingulata ( Loew) ( Diptera: Tephritidae) collected from infested domesticated sweet cherry ( Prunus avium L.) in the USA and black cherry [ Prunus serotina Ehrh. (both Rosaceae)] from the SMO and EVTM. We report evidence for marked post-mating reproductive isolation among certain R. cingulata populations. The high levels of reproductive isolation were observed between R. cingulata flies from populations in the USA and SMO differed from the pattern seen for R. pomonella, primarily involving the EVTM. In addition, egg hatch was significantly reduced for crosses between SMO males and EVTM females, but not greatly in the opposite direction. We discuss potential causes for the different patterns of post-mating reproductive isolation among Rhagoletis flies. [ABSTRACT FROM AUTHOR]

Megaloprepus caerulatus is a Neotropical species with a highly specialised niche, found from Mexico to Bolivia, primarily in mature tropical forests lower than 1500 masl. It is also the damselfly with the largest wingspan in the world. Recent studies found strong genetic isolation among populations of M. caerulatus. Further studies found genetic and morphological divergence, but ecological divergence was not tested. Here, we test for ecological divergence by evaluating niche differences among populations of M. caerulatus in Los Tuxtlas (Mexico), Corcovado (Costa Rica), Barro Colorado (Panama), and La Selva (Costa Rica). We used Ecological Niche Modelling (ENM) to compare potential distribution ranges, and we estimated the breadth and overlap of the ecological niche using equivalence and similarity tests. The potential distributions estimated with ENM were heavily fragmented and we found no geographic overlap of potential distributions among populations. However, we found geographic correspondence between populations with a close phylogenetic relationship. Even though all similarity tests were non-significant, the results of the equivalence tests suggest niche divergence between Corcovado and the other three populations, but also between Barro Colorado (Panama) and La Selva. These results show evidence of strong ecological divergence in Corcovado and Barro Colorado populations. [ABSTRACT FROM AUTHOR]

Abstract: We analyzed the phylogenetic and time–space relationships (phylodynamics) of 181 isolates of vesicular stomatitis New Jersey virus (VSNJV) causing disease in Mexico and the United States (US) from 2005 through 2012. We detail the emergence of a genetic lineage in southern Mexico causing outbreaks in central Mexico spreading into northern Mexico and eventually into the US. That emerging lineage showed higher nucleotide sequence identity (99.5%) than that observed for multiple lineages circulating concurrently in southern Mexico (96.8%). Additionally, we identified 58 isolates from Mexico that, unlike previous isolates from Mexico, grouped with northern Central America clade II viruses. This study provides the first direct evidence for the emergence and northward migration of a specific VSNJV genetic lineage from endemic areas in Mexico causing VS outbreaks in the US. In addition we document the emergence of a Central American VSNJV genetic lineage moving northward and causing outbreaks in central Mexico. [Copyright &y& Elsevier]

• Two sympatric species of Spathiphyllum produce different scent compounds. • Most pollinators are Hymenopterans, especially pollen-collecting bees. • Contrary to expectations, male euglossine bees were not the main pollinators. • Differences in the pollinator spectrum are probably related to growth habit and the habitat of the plants. In the genus Spathiphyllum (Araceae), pollination studies and observations mainly suggest that male euglossine bees (Euglossini: Apidae) are the main pollinators, and Spathiphyllum species seem to fit perfectly in the perfume flower pollination syndrome. Other flower visitors, mainly stingless bees (Meliponini), are frequently observed but mostly regarded as pollen-thieves. Nevertheless, two previous investigations considered stingless bees to be major pollinators of two Spathiphyllum species, which raises the question of whether their role as pollinators has been underestimated so far. We conducted a comprehensive study on the reproductive biology of Spathiphyllum croatii and S. ortgiesii , two sympatric species in the region of Los Tuxtlas, Mexico, and investigated their flowering phenology, floral visitors, floral scents, floral (micro-)morphology, reproductive success, and their capability for self-pollination. Spathiphyllum croatii grew in large clusters at open sites, S. ortgiesii in small, scattered populations in the forest understory. Both species were protogynous and obligate outcrossers. Visits of male euglossine bees were rare (< 10%) and only observed at S. croatii. The main pollinators were pollen-collecting Apis mellifera (Apini) and Plebeia sp. (Meliponini; > 60% of all visits) in S. croatii and Trigona fulviventris (Meliponini; > 90%) in S. ortgiesii. The floral scent of the two species was distinct in its composition, intensity, and emission cycle. Spathiphyllum croatii had several dozen scent compounds, while the bouquet of S. ortgiesii consisted of only three compounds. The absence of a larger number of male euglossine visitors is remarkable, given that most of the major compounds in the scent of the two species are well-known male euglossine attractants. We conclude that our study species are specialized for pollination by pollen-collecting bees, and discuss potential reasons for the distinct pollinator spectra of the two plant species and the comparatively low abundance of euglossine bees as floral visitors. [ABSTRACT FROM AUTHOR]

Abstract: Escherichia coli occur as either free-living microorganisms, or within the colons of mammals and birds as pathogenic or commensal bacteria. Although the Mexican population of intestinal E. coli maintains high levels of genetic diversity, the exact mechanisms by which this occurs remain unknown. We therefore investigated the role of homologous recombination and point mutation in the genetic diversification and population structure of Mexican strains of E. coli. This was explored using a multi locus sequence typing (MLST) approach in a non-outbreak related, host-wide sample of 128 isolates. Overall, genetic diversification in this sample appears to be driven primarily by homologous recombination, and to a lesser extent, by point mutation. Since genetic diversity is hierarchically organized according to the MLST genealogy, we observed that there is not a homogeneous recombination rate, but that different rates emerge at different clustering levels such as phylogenetic group, lineage and clonal complex (CC). Moreover, we detected clear signature of substructure among the A+B1 phylogenetic group, where the majority of isolates were differentiated into four discrete lineages. Substructure pattern is revealed by the presence of several CCs associated to a particular life style and host as well as to different genetic diversification mechanisms. We propose these findings as an alternative explanation for the maintenance of the clear phylogenetic signal of this species despite the prevalence of homologous recombination. Finally, we corroborate using both phylogenetic and genetic population approaches as an effective mean to establish epidemiological surveillance tailored to the ecological specificities of each geographic region. [Copyright &y& Elsevier]

Extreme environments are often considered a predation refuge for organisms living in them. In southern Mexico several species of poeciliid fishes are undergoing incipient speciation in a variety of extreme (i.e. permanently dark and/or sulphidic) freshwater systems, and previous research has demonstrated reproductive isolation between populations from sulphidic and adjacent benign habitats. In the present study, we investigated bird predation rates (measured as successful captures per minute) in two sulphidic surface and several benign surface habitats, to test the hypothesis that extreme habitats are predation refuges. We found capture rates to be approximately 20 times higher in sulphidic environments: probably facilitated by extremophile poeciliids spending most of their time at the water surface, where they engage in aquatic surface respiration as a direct response to hypoxia. Even birds that are usually not considered major fish predators regularly engage in fish predation in the toxic habitats of southern Mexico. Our results demonstrate that extreme environments do not necessarily represent a refuge from predation, and we discuss the general importance of predation in driving incipient speciation in these systems. Finally, we hypothesize that natural selection via avian predation may play an important role in maintaining reproductive isolation between divergent poeciliid populations. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 101, 417–426. [ABSTRACT FROM AUTHOR]

We performed a quantitative trait locus (QTL) analysis of epicuticular hydrocarbon variation in 1650 F2 males from crosses of Baja California and mainland Mexico populations of Drosophila mojavensis cultured on two major host cacti. Principal component (PC) analysis revealed five PCs that accounted for 82% of the total epicuticular hydrocarbon variation. Courtship trials with mainland females were used to characterize hydrocarbon profiles of mated and unmated F2 males, and logistic regression analysis showed that cactus substrates, two PCs, and a PC by cactus interaction were associated with mating success. Multiple QTLs were detected for each hydrocarbon PC and seven G × E (cactus) interactions were uncovered for the X, second, and fourth chromosomes. Males from the courtship trials and virgins were used, so “exposure to females” was included as a factor in QTL analyses. “Exposed” males expressed significantly different hydrocarbon profiles than virgins for most QTLs, particularly for the two PCs associated with mating success. Ten QTLs showed G × E (exposure) interactions with most resulting from mainland genotypes expressing altered hydrocarbon amounts when exposed to females compared to Baja genotypes. Many cactus × exposure interaction terms detected across QTL and all PCs confirmed that organ pipe-reared males expressed significantly lower hydrocarbon amounts when exposed to females than when reared on agria cactus. Epicuticular hydrocarbon variation in D. mojavensis is therefore a multigenic trait with some epistasis, multiple QTLs exhibited pleiotropy, correlated groups of hydrocarbons and cactus substrates determined courtship success, and males altered their hydrocarbon profiles in response to females. [ABSTRACT FROM AUTHOR]

Understanding the spatial structure of a population is critical for effective assessment and management. However, direct observation of spatial dynamics is generally difficult, particularly for marine mammals. California sea lions ( Zalophus californianus) are polygynous pinnipeds distributed along the Pacific coast of North America. The species’ range has been subdivided into three management stocks based on differences in mitochondrial DNA, but to date no studies have considered nuclear genetic variation, and thus we lack a comprehensive understanding of gene flow patterns among sea lion colonies. In light of recent population declines in the Gulf of California, Mexico, it is important to understand spatial structure to determine if declining sea lion colonies are genetically isolated from others. To define population subdivision and identify sex biases in gene flow, we analysed a 355-bp sequence of the mitochondrial DNA control region and 10 polymorphic microsatellite loci from 355 tissue samples collected from six colonies distributed along Mexican waters. Using a novel approach to estimate sex biases in gene flow, we found that male sea lions disperse on average 6.75 times more frequently than females. Analyses of population subdivision strongly suggest a pattern of isolation by distance among colonies and challenge current stock definitions. Based on these results, we propose an alternative classification that identifies three Mexican management units: Upper Gulf of California, Southern Baja Peninsula, and Upper Pacific Coast of Baja. This revised classification should be considered in future assessment and management of California sea lion populations in Mexican waters. [ABSTRACT FROM AUTHOR]

Triatoma longipennis (Usinger) is an important vector of Trypanosoma cruzi in western, central and northern Mexico, due to its wide distribution, high infection rates, and epidemiological indices. However, its population genetics has not been completely characterized. In this study, the intra-specific relationships between different T. longipennis populations were analyzed from seven states in Mexico using mitochondrial cyt B as a marker. Our results show that the population of Jalisco was the most diverse, with the highest genetic and haplotypic variation (Hd = 0.978, π = 0.099 and θ = 0.079), even 25 times higher than some other populations analyzed. Heterogeneous migration and gene flow were observed without relation to their geographical distribution, that is, nearby populations may present high values of gene flow with low migration. In contrast, remote populations have low gene flow values with high migration. Genetic isolation was apparently present in the Guanajuato population, however, Mantel's analyzes to determine when an isolation by distance is present did not show correlation between genetic (F ST) and geographic (Km) distances (P = 0.064). The STRUCTURE analyzes showed that populations such as Chihuahua, Jalisco, Nayarit and Michoacán appear to show a similar population structure, suggesting a common ancestor. Our results suggest two routes of diversification of T. longipennis highly influenced by anthropogenic effects. Elucidation of the population genetic structure of T. longipennis will help to better understand the role of gene flow and migration in the dispersal of this important Chagas disease vector. [Display omitted] • The genetic variation between different M. longipennis populations was analyzed. • It was suggested as center of dispersion and diversification the Jalisco population. • Some populations, such as Guanajuato showed genetic isolation. • Role of gene flow and migration on dispersal of this species is provided. [ABSTRACT FROM AUTHOR]