Patterns Of Geographic Differentiation Research Articles

Morphology supports the geographic pattern of genetic differentiation of Pinus sylvestris (Pinaceae) in the Iberian Peninsula

Pinus syvestris from the Iberian Peninsula was biometrically compared, using needle morphological and anatomical characteristics from 15, and cone morphological characteristics from nine natural populations. Samples of Scots pine represent subspecies nevadensis and varieties pyrenaica, catalaunica, and iberica. Analyses included 25 needle and 17 cone characteristics and numerical methods (principal component analysis, discrimination analysis, agglomeration on Euclidean/Mahalanobis’ distances). A strong differences were detected between P. sylvestris subsp. nevadensis when compared to varieties pyrenaica and iberica, and a closer relationship to var. catalaunica in needle characteristics. In cone characteristics, the differences were at a similar level. Alien individuals were found within every taxon and population. Samples from the southern part of Sistema Central had the highest level of alien individuals. The geographic pattern of differentiation resembles patterns previously revealed using molecular and isoenzymatic markers. We could not detect characteristics specific to either P. sylvestris subsp. nevadensis or varieties of P. sylvestris subsp. sylvestris. Supplemental data for this article is available online at https://doi.org/10.1080/11263504.2021.1922532 .

Genetic data and niche differences suggest that disjunct populations of Diglossa brunneiventris are not sister lineages

Abstract Disjunct distributions within a species are of great interest in systematics and biogeography. This separation can function as a barrier to gene flow when the distance among populations exceeds the dispersal capacity of individuals, and depending on the duration of the barrier, it may eventually lead to speciation. Here, we describe patterns of geographic differentiation of 2 disjunct populations of Diglossa brunneiventris separated by ~1,000 km along the Andes. Diglossa brunneiventris vuilleumieri is isolated in northern Colombia, while Diglossa brunneiventris brunneiventris has a seemingly continuous distribution across Peru, Bolivia, and Chile. We sequenced mitochondrial and nuclear DNA of the 2 D. brunneiventris subspecies to evaluate whether they form a monophyletic clade, while including the other 3 species within the carbonaria complex (D. gloriosa, D. humeralis, and D. carbonaria). We also constructed ecological niche models for each D. brunneiventris subspecies to compare their climatic niches. We found that when using all available molecular data, the 2 D. brunneiventris subspecies are not sister lineages. In fact, each subspecies is more closely related to other species in the carbonaria complex. Our niche modeling analyses showed that the subspecies are occupying almost entirely different climatic niches. An additional and not expected result was that the carbonaria complex might encompass more cryptic species than previously considered. We suggest reevaluating the taxonomic status of these brunneiventris populations, especially the northern subspecies, given its highly restricted range and potential threatened status.

Unique Evolution of Hyla hallowellii Among Amphibians of the Central Ryukyus, Japan (Anura: Hylidae).

Fauna of the Central Ryukyus includes a high percentage of endemic species, and Hallowell's tree frog Hyla hallowellii Thompson, 1912 is one of such elements, occurring in a total of eight islands in the Amami and Okinawa Island groups. Using samples representing all of these eight island populations, we studied variations in morphology, karyotype, allozyme, and mtDNA, to clarify the pattern of geographic differentiation of H. hallowellii and consider factors for its formation. We could not clearly discriminate one population from another in morphology, nor could we find any interpopulation difference in karyotype. From genetic analyses, using allozymes and cyt b, we found low overall differentiations among populations. However, the southern populations from Okinawajima and Yoronjima were genetically nearly identical with the northern Amamioshima population. From that group the geographically intermediate Tokunoshima and Kakeromajima populations showed prominent differentiations. These patterns of geographical differentiation greatly differ from those known in other amphibian species of the Central Ryukyus, and suggest that H. hallowellii has evolutionary history unique to the species.

Feral pigeon populations: their gene pool and links with local domestic breeds

Columba livia is a wild bird whose domestication has led to a large number of pigeon breeds. The occasional loss or straying of domestic birds determined the origin of feral pigeons, which are now widespread all around the world. In this study, we assumed that the main contribution to feral populations is provided by domestic breeds reared in the same areas. We tested this hypothesis by analysing the variability of 12 microsatellite loci in nine Italian feral populations sampled in areas with different intensities of breeding and selecting domestic breeds. We included in the analysis samples belonging to ten domestic lineages commonly bred in Italy. The pattern of geographic differentiation of feral populations turned out to be rather complex and only partially explained by the geographic distance between populations. This pattern can be understood only when the domestic breeds were included in the analysis. In particular, feral populations located in regions with a long-lasting tradition of pigeon breeding showed a high level of admixture with domestic breeds, in particular with Racing Homer and Piacentino. Ferals from Bolzano, Venice and Sassari were characterized by unique genetic components, mostly not shared by other feral populations and by the considered domestic breeds. Our results further emphasize the complex genetic structure of feral populations whose origin can be properly investigated by taking into account the pool of domestic pigeons bred in the considered area.

Dissection of ancestral genetic contributions to Creole goat populations

Goats have played a key role as source of nourishment for humans in their expansion all over the world in long land and sea trips. This has guaranteed a place for this species in the important and rapid episode of livestock expansion triggered by Columbus’ arrival in the Americas in the late 1400s. The aims of this study are to provide a comprehensive perspective on genetic diversity in American goat populations and to assess their origins and evolutionary trajectories. This was achieved by combining data from autosomal neutral genetic markers obtained in more than two thousand samples that encompass a wide range of Iberian, African and Creole goat breeds. In general, even though Creole populations differ clearly from each other, they lack a strong geographical pattern of differentiation, such that populations of different admixed ancestry share relatively close locations throughout the large geographical range included in this study. Important Iberian signatures were detected in most Creole populations studied, and many of them, particularly the Cuban Creole, also revealed an important contribution of African breeds. On the other hand, the Brazilian breeds showed a particular genetic structure and were clearly separated from the other Creole populations, with some influence from Cape Verde goats. These results provide a comprehensive characterisation of the present structure of goat genetic diversity, and a dissection of the Iberian and African influences that gave origin to different Creole caprine breeds, disentangling an important part of their evolutionary history. Creole breeds constitute an important reservoir of genetic diversity that justifies the development of appropriate management systems aimed at improving performance without loss of genomic diversity.

Genetic differentiation and phylogeography of Mediterranean-North Eastern Atlantic blue shark (Prionace glauca, L. 1758) using mitochondrial DNA: panmixia or complex stock structure?

BackgroundThe blue shark (Prionace glauca, Linnaeus 1758) is one of the most abundant epipelagic shark inhabiting all the oceans except the poles, including the Mediterranean Sea, but its genetic structure has not been confirmed at basin and interoceanic distances. Past tagging programs in the Atlantic Ocean failed to find evidence of migration of blue sharks between the Mediterranean and the adjacent Atlantic, despite the extreme vagility of the species. Although the high rate of by-catch in the Mediterranean basin, to date no genetic study on Mediterranean blue shark was carried out, which constitutes a significant knowledge gap, considering that this population is classified as “Critically Endangered”, unlike its open-ocean counterpart.MethodsBlue shark phylogeography and demography in the Mediterranean Sea and North-Eastern Atlantic Ocean were inferred using two mitochondrial genes (Cytb and control region) amplified from 207 and 170 individuals respectively, collected from six localities across the Mediterranean and two from the North-Eastern Atlantic.ResultsAlthough no obvious pattern of geographical differentiation was apparent from the haplotype network, Φst analyses indicated significant genetic structure among four geographical groups. Demographic analyses suggest that these populations have experienced a constant population expansion in the last 0.4–0.1 million of years.DiscussionThe weak, but significant, differences in Mediterranean and adjacent North-eastern Atlantic blue sharks revealed a complex phylogeographic structure, which appears to reject the assumption of panmixia across the study area, but also supports a certain degree of population connectivity across the Strait of Gibraltar, despite the lack of evidence of migratory movements observed by tagging data. Analyses of spatial genetic structure in relation to sex-ratio and size could indicate some level of sex/stage biased migratory behaviour.

Population structure and patterns of geographic differentiation of Bactrocera oleae (Diptera: Tephritidae) in Eastern Mediterranean Basin

The olive fly (Bactrocera oleae) is the most destructive pest of olives in most commercial olive-growing regions worldwide. Significant economic damage to olive production is caused by the larvae of this fly, which feed on the pulp of Olea fruits. Studying the genetic structure of insect pest populations is essential for the success of pest management strategies. Our primary goal in the present study was to examine the population structures of olive flies collected over a wide geographic area from Turkey, a representative of eastern Mediterranean region, using two mitochondrial DNA sequences as genetic markers. The data revealed a high level of genetic variability in olive fly populations and a moderate level of genetic differentiation between Mediterranean and Aegean populations in Turkey. We also merged the sequences obtained in the present study with previously published sequences from across the world into the data matrix. Strong population substructure and a significant correlation between genetic and geographic distances were detected in northern Mediterranean basin populations of B. oleae, indicating the possibility of a westward expansion of the species in the continent. In addition, our results revealed a very close genetic relationship between the Aegean and Iranian populations, which suggests that B. oleae was introduced to Iran from western parts of Turkey. However, additional markers and analytical approaches are required to determine the exact colonization route of olive fly.

Impact of Orogeny and Environmental Change on Genetic Divergence and Demographic History of Dipus sagitta (Dipodoidea, Dipodinae) since the Pliocene in Inland East Asia

Inland East Asia encompasses particular landscapes, including discontinuous large deserts isolated by mountains, and these landscapes have been greatly impacted by the uplift of the Qinghai-Tibetan Plateau (QTP) since the Pliocene. However, little research has been performed on the impact of desertification on the evolutionary history of animals in this area. We examined a widespread desert rodent species, Dipus sagitta, to better understand the influences of geological events on the evolutionary history and phylogeographic patterns. We sequenced two mitochondrial genes and three nuclear genes from 237 individuals collected from 43 populations across inland East Asia. Phylogenetic, network, intraspecific delimitation, and population structure analyses identified a structured pattern of geographic differentiation with six well-defined evolutionary clades. High mountains (such as the Tianshan Mountains) and important climate demarcation lines (such as the 200 mm isohyet) were inferred as genetic barriers among the six clades by BARRIER analysis. The most recent common ancestor of D. sagitta was estimated to have existed in late Miocene, and the first clade was estimated to have diverged at c. 7.57 Ma, whereas the later clade diversified rapidly at approximately 2.56–1.53 Ma during the Pleistocene. Demographic analyses suggested different demographic histories among the distinct clades, and the continuous expansion that occurred during the climate oscillation period appeared to be more closely related to the increasing aridification caused by orogeny rather than climate oscillation.

Taxonomic differentiation of Cupressus sempervirens and C. atlantica based on morphometric evidence

We investigated the interspecific morphological relationships of two related Mediterranean Cupressus taxa and the possible geographic differentiation of Eastern Mediterranean C. sempervirens using morphometric analysis. A total of 446 individuals, representing eight C. atlantica (Morocco) and 10 C. sempervirens (Greece, Turkey and Lebanon) populations were examined. The 17 morphological characters of cone, seed and shoot with leaves were measured and analysed statistically. Significant morphological differences between C. atlantica and C. sempervirens were detected for the majority of analysed characters. For C. sempervirens, significant differences were also detected and these were related to its three regions of origin, the Greek Islands, Taurus Mts and Lebanon Mts. Multivariate analyses did not indicate a clear geographic pattern of differentiation in C. sempervirens populations. A relatively low level of phenotypic differentiation was detected between populations originating from the Greek Islands and Taurus Mts. We also observed a moderate multivariate differentiation between the Lebanese and remaining C. sempervirens populations. Phenotypic differentiation detected in the Asian part of the C. sempervirens range reflects patterns of differentiation similar to those described for other taxa occurring in the Taurus and Lebanon Mts.

Phylogeography and demographic history of the Andean degu,Octodontomys gliroides(Rodentia: Octodontidae)

The Andean degu, Octodontomys gliroidesGervais & d'Orbigny, 1844, has a broad distribution inhabiting pre-Andean pre-Puna and Puna environments of tropical South America. In order to understand the phylogeographic patterns of Octodontomys gliroides, we sequenced 579 bp of the mitochondrial DNA control region from 100 individuals collected from 20 populations across its entire distributional range. The phylogenetic and parsimony network, in conjunction with analysis of molecular variance (AMOVA), revealed a structured pattern of geographic differentiation of O. gliroides, with the occurrence of two well-defined evolutionary lineages: lineage A, restricted to Bolivia and Chile, and lineage B, restricted mainly to Argentina. Analysis of population structure inferred three genetic clusters along the distribution of O. gliroides that mostly agree with the four major barriers inferred by BARRIER analysis (e.g. rivers, salt flats, deserts, and mountain systems). In addition to the significant differentiation found among all levels studied, a positive correlation was identified between genetic and geographic distance, similar to as expected under the isolation-by-distance model. The most recent common ancestor of O. gliroides was estimated as c. 5.99 Mya, and the divergence between lineages A and B is estimated to have occurred by the Middle Pleistocene, about 0.69 Mya. The mismatch distributions and neutrality tests suggested a signal of population range expansion for both lineages coincident with major climatic changes that occurred during the wet–dry events of the Pleistocene in the Andean Puna region. Bayesian skyline plots (BSPs) for lineage A suggest a long history of constant population size followed by a period of slight to moderate demographic expansion at c. 0.04 Mya, whereas lineage B remained unclear after BSP analysis, probably because of the limited sample size.

Geographic Differentiation of Tree Ferns (Cyatheales) in Tropical America

Abstract The patterns of geographic differentiation in fern species have been linked to climatic differences across regions and the distribution of available habitat. In this paper, the association between some climatic features and patterns of geographic differentiation in American tree ferns was evaluated. For this, the occurrence ranges of 190 species were plotted and then analysed using track analysis. Here we identify six generalised tracks that span the main highland regions of tropical America: the Andes, the Guyana Highlands, the Brazilian Atlantic coast, lower Central America, the Greater Antilles, and upper Central America-Mexico. We did not find an association between cloud forest habitat and the differentiation pattern revealed by generalised tracks in Central America. Instead, these patterns are congruent with well-documented geological boundaries in the region. Climatic variables associated with cloud forest habitat were extracted from each generalised track and subjected to ANOVA, showing t...

The Major Y-Chromosome Haplogroup R1b-M269 in West-Europe, Subdivided by the Three SNPs S21/U106, S145/L21 and S28/U152, Shows a Clear Pattern of Geographic Differentiation

More than 2600 unrelated males from West-Europe were analysed by molecular hybridization experiments for the p49a,fTaq I polymorphisms. A total of 895 subjects (34%), belonging to haplogroup M269, were identified and further analysed for the three SNPs, S21/U106, S145/L21 and S28/U152; these three SNPs define the Northwest, West and South European sub-haplogroups, respectively. These haplogroups showed quite different frequency distribution patterns within West-Europe, with frequency peaks in Northern Europe, in Brittany in France and in Northern Italy/Southern France.

A homogenizing process of selection has maintained an "ultra-slow" acetylation NAT2 variant in humans.

N-Acetyltransferase 2 (NAT2) is an important enzyme involved in the metabolism of a wide spectrum of naturally occurring xenobiotics, including therapeutic drugs and common environmental carcinogens. Extensive polymorphism in NAT2 gives rise to a wide interindividual variation in acetylation capacity, which influences individual susceptibility to various drug-induced adverse reactions and cancers. Striking patterns of geographic differentiation have been described for the main slow acetylation variants of the NAT2 gene, suggesting the action of natural selection at this locus. In the present study, we took advantage of whole-genome sequence data available from the 1000 Genomes project to investigate the global patterns of population genetic differentiation at NAT2 and determine whether they are atypical compared with the remaining variation of the genome. The nonsynonymous substitution c.590G>A (rs1799930) defining the slow NAT2*6 haplotype cluster exhibited an unusually low FST value compared with the genome average (FST = 0.006, P = 0.016). It was indicated as the most likely target of a homogenizing process of selection promoting the same allelic variant in globally distributed populations. The rs1799930 A allele has been associated with the slowest acetylation capacity in vivo, and its substantial correlation with the subsistence strategy adopted by past human populations suggests that it may have conferred a selective advantage in populations shifting from foraging to agricultural and pastoral activities in the Neolithic period. Results of neutrality tests further supported an adaptive evolution of the NAT2 gene through either balancing selection or directional selection acting on multiple standing slow acetylation variants.

Population genetics of Mediterranean and Saharan olives: geographic patterns of differentiation and evidence for early generations of admixture

The olive (Olea europaea subsp. europaea) was domesticated in the Mediterranean area but its wild relatives are distributed over three continents, from the Mediterranean basin to South Africa and south-western Asia. Recent studies suggested that this crop originated in the Levant while a secondary diversification occurred in most westward areas. A possible contribution of the Saharan subspecies (subsp. laperrinei) has been highlighted, but the data available were too limited to draw definite conclusions. Here, patterns of genetic differentiation in the Mediterranean and Saharan olives are analysed to test for recent admixture between these taxa. Nuclear microsatellite and plastid DNA (ptDNA) data were compiled from previous studies and completed for a sample of 470 cultivars, 390 wild Mediterranean trees and 270 Saharan olives. A network was reconstructed for the ptDNA haplotypes, while a Bayesian clustering method was applied to identify the main gene pools in the data set and then simulate and test for early generations of admixture between Mediterranean and Saharan olives. Four lineages of ptDNA haplotypes are recognized: three from the Mediterranean basin and one from the Sahara. Only one haplotype, primarily distributed in the Sahara, is shared between laperrinei and europaea. This haplotype is detected once in 'Dhokar', a cultivar from the Maghreb. Nuclear microsatellites show geographic patterns of genetic differentiation in the Mediterranean olive that reflect the primary origins of cultivars in the Levant, and indicate a high genetic differentiation between europaea and laperrinei. No first-generation hybrid between europaea and laperrinei is detected, but recent, reciprocal admixture between Mediterranean and Saharan subspecies is found in a few accessions, including 'Dhokar'. This study reports for the first time admixture between Mediterranean and Saharan olives. Although its contribution remains limited, Laperrine's olive has been involved in the diversification of cultivated olives.

Characterization of Sudanese pearl millet germplasm for agro-morphological traits and grain nutritional values

Pearl millet (Pennisetum glaucum(L.) R. Br.) is an important staple cereal cultivated in the arid and semi-arid tropics of Asia and Africa, regions severely affected by malnutrition. Knowledge about the extent of genetic variability and patterns of agro-morphological variation in local germplasm from a target region is an important prerequisite for efficient crop improvement. To assess the potential of Sudanese pearl millet landraces as sources of desirable traits for pearl millet improvement including biofortification, a total of 225 accessions were evaluated in Sudan at three locations for agro-morphological traits and at one location for grain mineral nutrient contents (Fe, Zn, Ca, P, K, Mg, Mn, S, Na, Cu and β-carotene). Genetic variation was highly significant, but relatively limited for some agro-morphological traits (62–78 d to flowering, 119–188 cm plant height and 16–34 cm panicle length), pointing to the potential usefulness of a targeted diversification for these traits. Self-pollinated grain micronutrient contents showed a wide variation: 19.7–86.4 mg/kg for Fe and 13.5–82.4 mg/kg for Zn. Significant and positive correlations among most of the nutritional traits were observed; therefore, enhancement of the concentrations of some nutrients will lead to the improvement of other related nutrients. No significant associations were observed between the nutritional and agro-morphological traits, indicating good prospects for simultaneous improvement of both trait categories. No clear patterns of geographic differentiation for specific traits were detected for the Sudanese pearl millet. Nutrient-rich accessions were identified and those with acceptable agro-morphological traits are encouraging materials for future pearl millet biofortification programmes in Sudan.

Minimal Genetic Structure in the Cerulean Warbler Despite Evidence for Ecological Differentiation among Populations

Abstract. The Cerulean Warbler (Setophaga cerulea) is one of the most rapidly declining warblers in North America. Our previous genetic work suggested that this migratory songbird has no significant population genetic structure in the northern and western parts of its breeding range, and for conservation purposes we assigned all sampled populations to a single genetic management unit. Here, we expand this work to include the entire breeding range of the Cerulean Warbler, given recent evidence for morphological and ecological differentiation between the northern and southern sections of that range. We assayed variation in four microsatellite loci and an 841-base-pair fragment of the mitochondrial control region, finding support for low but significant population-genetic structure in the mitochondrial marker. Estimates of population-genetic structure for pairs of sampling locations did not detect a clear geographic pattern of differentiation, and a hierarchical AMOVA did not reveal significant structure bet...

Games within borders: are geographically differentiated taxes optimal?

The discontinuous tax treatment of sales at borders creates incentives for individuals to cross-border shop. This paper addresses whether it is optimal for a state composed of multiple regions to levy differentiated commodity tax rates across the regions. In a model where states maximize social welfare, a state’s optimal commodity tax system is almost always geographically differentiated. The optimal pattern of geographic differentiation critically depends on fundamental parameters as well as whether the state has a preference for high or low taxes. Under the assumption that utility is linear in consumption and that the elasticity of cross-border shopping is less than unity in absolute value, high-tax states will find it optimal to set a tax rate that is lower in the border region than in the periphery region and low-tax states will find it optimal to set a tax rate that is higher in the border region than in the periphery region. Optimizing high-tax states will set a higher tax rate in the border region if the social welfare measure is sufficiently redistributive. With welfare maximization, it is possible for taxes to be higher in the region near the state border—an outcome that cannot arise when the government cares only about total tax revenue.

Genetic consequences of anagenetic speciation in Acer okamotoanum (Sapindaceae) on Ullung Island, Korea

Anagenesis (also known as phyletic speciation) is an important process of speciation in endemic species of oceanic islands. We investigated genetic variation in Acer okamotoanum, an anagenetically derived species endemic to Ullung Island, South Korea, to infer genetic consequences of anagenesis in comparison with other groups that have undergone cladogenesis (and adaptive radiation). We examined genetic variation based on eight polymorphic microsatellite markers from 145 individuals of A. okamotoanum and 134 individuals of its putative progenitor A. mono. We employed standard population genetic analyses, clustering analyses, Bayesian clustering analyses in STRUCTURE and bottleneck analyses. Based on both the Neighbor-Joining tree and Bayesian clustering analyses, clear genetic distinctions were found between the two species. Genetic diversity in terms of allelic richness and heterozygosity shows slightly lower levels in A. okamotoanum in comparison with A. mono. Bayesian clustering analyses showed a relatively high F-value in the cluster of A. okamotoanum, suggesting a strong episode of genetic drift during colonization and speciation. There was no clear evidence of a bottleneck based on allelic frequency distribution and excess of observed heterozygotes, but the M-ratio indicated a historical bottleneck in several populations of A. okamotoanum. No geographical genetic structure within the island was found, and the genetic variation among populations of A. okamotoanum was quite low. We hypothesized that genetic consequences of oceanic-endemic plants derived via anagenesis would be quite different from those derived via cladogenesis. Populations of A. okamotoanum form a cluster and are clearly differentiated from A. mono, which suggests a single origin for the anagenetically derived island endemic. No pattern of geographical differentiation of populations occurs in A. okamotoanum, which supports the concept of initial founder populations diverging through time by accumulation of mutations in a relatively uniform environment without further specific differentiation.

Games Within Borders: Are Geographically Differentiated Taxes Optimal?

The discontinuous tax treatment of sales at borders creates incentives for individuals to cross-border shop. This paper addresses whether it is optimal for a state composed of multiple regions to levy differentiated commodity tax rates across the regions. In a model where states maximize social welfare, a state’s optimal commodity tax system is almost always geographically differentiated. The optimal pattern of geographic differentiation critically depends on fundamental parameters as well as whether the state has a preference for high or low taxes. Under the assumption that utility is linear in consumption and that the elasticity of cross-border shopping is less than unity in absolute value, high-tax states will find it optimal to set a tax rate that is lower in the border region than in the periphery region and low-tax states will find it optimal to set a tax rate that is higher in the border region than in the periphery region. Optimizing high-tax states will set a higher tax rate in the border region if the social welfare measure is sufficiently redistributive. With welfare maximization, it is possible for taxes to be higher in the region near the state border -- an outcome that cannot arise when the government cares only about total tax revenue.

Geographic distribution and spatial differentiation in the color pattern of abdominal stripes of the Neotropical stingless bee Melipona quadrifasciata (Hymenoptera: Apidae)

Melipona quadrifasciata Lepeletier, 1836, regionally known as "mandaçaia", has been traditionally divided in two distinct subspecies: M. quadrifasciata anthidioides and M. quadrifasciata quadrifasciata. The main difference between the subspecies refers to the yellow metasomal stripes which are continuous in M. q. quadrifasciata and discontinuous in M. q. anthidioides. This study investigated the geographic differentiation in the metasomal stripes and characterized the restriction sites in the mtDNA of both chromatic types. Specimens from 198 localities were examined, and the variation observed in the pattern of stripes was grouped into distinct classes. The distribution pattern found in the present work agrees with the previously reported pattern: M. q. quadrifasciata inhabits the southern portion of the distribution, from Misiones, Argentina, southeastern Paraguay and Rio Grande do Sul to southern São Paulo, and M. q. anthidioides ranges from northeastern São Paulo to the northern Diamantina Plateau, Bahia, and westwards to the central portion of the Goiás state. It is documented for the first time the occurrence of two populations with continuous stripes inhabiting disjunct areas in relation to M. q. quadrifasciata - one in northern Minas Gerais and another in northeastern Bahia and Sergipe. The data of RFLP showed two restriction patterns, one present in M. q. quadrifasciata, and another in M. q. anthidioides and in populations with continuous metasomal stripes from northern Minas Gerais and northeastern Bahia and Sergipe. The observed patterns of geographic differentiation of M. quadrifasciata suggests the occurrence of repeated events of geographical isolation, followed by range expansion, that occurred probably during the cycles of climatic changes in the Pleistocene.