Molecular differentiation and taxonomy of the sunwatcher toad-headed agama species complex <Emphasis Type="Italic">Phrynocephalus</Emphasis> superspecies <Emphasis Type="Italic">helioscopus</Emphasis> (Pallas 1771) (Reptilia: Agamidae)

Lizards of the sunwatcher toad-headed agama species complex Phrynocephalus superspecies helioscopus, mostly distributed in Central Asia and Middle East, were examined using analysis of variation at the mitochondrial cytochrome oxidase c subunit I gene fragment and fingerprint analysis of nuclear DNA (inter-SINE PCR technique). A total of 86 individual tissue samples from 53 populations, to the full extent representing different parts of the species complex range, were subjected to molecular genetic examination, and surprisingly deep differentiation was revealed. The populations analyzed split into 12 isolated phylogroups, many of which were characterized by a narrow range and genetic isolation. Monophyly of sunwatcher (Ph. helioscopus) and Persian (Ph. persicus) toad-headed agamas was confirmed. However, both of these species probably represent the species complexes. Zoogeography of Central Asiais discussed.     

The comparative aspects of spatial ecology of lizards exemplified by the toad-headed lizards (Reptilia, Agamidae, Phrynocephalus)

The possibility of analysis of phylogenetic parameters of the spatial distribution of populations is discussed by an example of the agamid toad-headed lizards (Phrynocephalus). Summarizing both original and published data on the individual home ranges and the relocation of individuals of 30 populations from 12 species showed that differentiation of the type of spatial distribution is weak in toad-headed lizards. This observation confirms the idea that this clade of agamids is phylogenetically young and relatively recently radiated. At the interspecific level, positive correlation between home range size and body size was observed in the studied group. Such spatial parameters, shared by all toad-headed lizards, as relatively large size and weakly structured individual home ranges can be explained by the peculiarities of their reproduction features and their foraging mode. The individual type of space-usage in toad-headed does not fit the traditional scheme dividing all the lizards into the territorial Iguania and the nonterritorial Autarchoglossa.     

Genetic Variability in the Yellow-Necked Field Mouse (<Emphasis Type="Italic">Sylvaemus flavicollis</Emphasis> Melch., 1834, Muridae,Rodentia) at the Eastern Border of the Range

The first characterization of the genetic variability in populations of S. flavicollis on the eastern border of the range is presented. Seven individuals from the most northeastern habitat of the species (Middle Urals) were karotyped. No deviations from the standard chromosome set, either by the chromosome number or morphology, were revealed. Analysis of the mtDNA cytochrome b gene sequences (1133 bp) in 44 individuals from five populations on the eastern border of the species range (Middle and Southern Urals) resulted in identification of 17 haplotypes. All haplotypes were new and not found earlier in other parts of the species range. The genetic diversity indices and analysis of the demographic and genetic structure indicate a relatively recent origin of the populations under study as a result of rapid expansion. Phylogenetic analysis (97 haplotypes, including the GenBank data) showed that all haplotypes described at the eastern border of the range belonged to the same phylogroup distributed in the Balkan region, Northern and Eastern Europe, and Russia (Samara oblast). Close relationships between the examined populations and the populations from the northern part of the species range in Eastern Europe was demonstrated.     

Microsatellite DNA markers for three toad-headed lizard species (Phrynocephalus vlangalii, P. przewalskii and P. guttatus)

To assess the impact of natural landscapes on the population structure of lizards, 10 polymorphic microsatellite DNA markers were developed for the Qinghai toad-headed lizard, Phrynocephalus vlangalii. The number of alleles at these informative loci ranged from four to 28. The novel markers and those previously developed for Phrynocephalus przewalskii were cross-tested among three toad-headed lizard species P. vlangalii, P. przewalskii and P. guttatus. A high cross-utility rate of more than 58% was observed among these three species. These markers are expected to be useful tools for taxonomic considerations as well as population genetic analysis and future conservation management.     

A new record for Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) species complex of Turkey

In this study, species complex of Turkish Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) populations was determined by PCR‐based DNA analysis. According to phylogenetic analyses, the B. tabaci samples have been identified within three generic groups. A major part of the samples belonged to two invasive species, either Middle East–Asia Minor 1 (MEAM1) or Mediterranean (MED). In addition to these two invasive species, several samples collected from greenhouses and cotton fields have been found to be related to Middle East–Asia Minor 2 (MEAM2), which is the first record of Turkish B. tabaci species complex.     

Genotype relationships inMicroseris elegans (Asteraceae,Lactuceae) revealed by DNA amplification from arbitrary primers (RAPDs)

The genetic relationships among 10 inbred lines representing 10 populations of the autogamous annualMicroseris elegans from throughout California has been determined using random amplified polymorphic DNAs (RAPDs). Seventeen arbitrary 10 base pair primers produced 134 amplification products; 81 of these were shared by two or more strains. The 3 genotypes from Northern California are closely related as are 3 genotypes from Middle Californian populations which are not nearest neighbors. DNA fingerprinting with the oligonucleotide (GATA)₄ gave compatible results, but the comparison was limited to samples run on one gel. Isoenzyme patterns are compatible with the DNA results, but limited by the very low number of informative polymorphisms. The clustered relationship among genotypes within a species and their geographic distribution suggests very restricted genetic recombination and an origin of new populations from randomly dispersed achenes within the range of the species.     

The distribution of random amplified polymorphic DNA (RAPD) diversity amongst populations of Isotoma petraea (Lobeliaceae)

RAPDs were generated from plants of six populations of Isotoma petraea F. Muell. The species occurs on rock outcrops in southern and western Australia, with populations exhibiting different breeding systems, including complete autogamy, varying levels of outbreeding and complex hybridity. Non-metric multidimensional scaling (nMDS) analysis of the random amplified polymorphic DNA (RAPD) data set clearly resolved all populations. The Pigeon Rock population, which is home to both complex hybrid and structural homozygote plants, was divided into those two groups by the nMDS analysis. There was little diversity in highly autogamous populations, but levels were higher in the outbred Yackeyackine population. All complex hybrid populations and plants possessed numerous genetic system-specific RAPDs, some of which were shown to be held in fixed heterozygosity. Estimating G _ST using RAPDs has been problematical due to their dominance, and analytical methods usually rely on knowledge of the selfing rate or assume Hardy–Weinberg equilibrium. This assumption does not hold when populations exhibit fixed heterozygosity, and an alternative method, Shannon's Index, was used to partition genetic diversity. The distribution of genetic diversity fit expectations for an inbreeding species, with most of the variation (87.5%) occurring between populations. This compares to an average RAPD-based G _ST of 59.6% for inbreeding species generally and 15.5% for outbreeding species.     

Isoenzimatic analysis of four Anopheles (Kerteszia) cruzii (Diptera: Culicidae) populations of Brazil

Anopheles cruzii is a small sylvatic mosquito and primary human Plasmodium vector in Southern Brazil. The distribution of this bromeliad-breeding mosquito follows the Atlantic forest coastal distribution, where bromeliads are abundant. Morphological, genetic, and molecular polymorphisms among different populations have been reported and it has recently been suggested that An. cruzii is a complex of cryptic species. The aim of this work is to analyze the gene flow between different populations of An. cruzii collected in four localities within the geographic distribution range of the species, and to examine if An. cruzii is a complex of cryptic species. The genetic distances show that populations of the states of Santa Catarina, Sao Paulo, and Rio de Janeiro are genetically closer (0.032 to 0.083) than populations of Bahia (0.364 to 0.853) based on profiles from 10 distinct isoenzyme loci. The Fst was lower (0.077) when the Bahia population was excluded than when it was included (0.300) in the analyses. The inferred number of migrants per generation was 2.99 individuals among populations from the states of Santa Catarina, Sao Paulo, and Rio de Janeiro and 0.58 migrants per generation among all populations. Results suggest that An. cruzii is a complex of species and that the specimens of state of Bahia can be considered as belonging to a species that is distinct from other three closely-related populations studied.     

Can invasions occur without change? A comparison of G-matrices and selection in the peach-potato aphid,Myzus persicae

Most evolutionary research on biological invasions has focused on changes seen between the native and invaded range for a particular species. However, it is likely that species that live in human‐modified habitats in their native range might have evolved specific adaptations to those environments, which increase the likelihood of establishment and spread in similar human‐altered environments. From a quantitative genetic perspective, this hypothesis suggests that both native and introduced populations should reside at or near the same adaptive peak. Therefore, we should observe no overall changes in the G (genetic variance–covariance) matrices between native and introduced ranges, and stabilizing selection on fitness‐related traits in all populations. We tested these predictions comparing three populations of the worldwide pest Myzus persicae from the Middle East (native range) and the UK and Chile (separately introduced ranges). In general, our results provide mixed support for this idea, but further comparisons of other species are needed. In particular, we found that there has been some limited evolution in the studied traits, with the Middle East population differing from the UK and Chilean populations. This was reflected in the structure of the G ‐matrices, in which Chile differed from both UK and Middle East populations. Furthermore, the amount of genetic variation was massively reduced in Chile in comparison with UK and Middle East populations. Finally, we found no detectable selection on any trait in the three populations, but clones from the introduced ranges started to reproduce later, were smaller, had smaller offspring, and had lower reproductive fitness than clones from the native range.     

Phylogeography of North African Atlas cedar (Cedrus atlantica, Pinaceae): Combined molecular and fossil data reveal a complex Quaternary history

Northwest Africa is a major hotspot of plant biodiversity, but very little is known about the Quaternary range dynamics of plant species in this region. Here we investigate the range-wide population structure and phylogeography of Atlas cedar (Cedrus atlantica), an emblematic forest tree endemic to Morocco and Algeria. We genotyped 261 individuals from 11 populations using AFLP markers. Data were analyzed using both conventional F(ST)-based techniques and Bayesian clustering. Overall population differentiation was high (F(ST) = 0.25). Two major groups of populations were identified, one distributed through the Rif and Middle Atlas mountains in Morocco and the other through the Algerian Tell Atlas and Aurès mountains as well as the Middle Atlas. Combined molecular and fossil data indicate that C. atlantica survived the Last Glacial Maximum in at least three disjunct refugia along the coast of the Mediterranean Sea, whereas the Middle Atlas, today the core of the species range, has been colonized relatively recently (<10000 yr BP). The colonization history of individual populations has left clear imprints in their present-day diversity, which may vary greatly even between nearby stands. Our study illustrates how integrating different data sources and analytical approaches can help elucidate complex range dynamics that would otherwise remain undeciphered.     

Genetic diversity and structure of the endemic Caesalpinia hintonii complex (Leguminosae: Caesalpinioideae) in Mexico

The Caesalpinia hintonii complex is formed by five endemic species (C. hintonii, C. laxa, C. macvaughii, C. melanadenia and C. epifanioi) occurring in central Mexico. This species complex is under incipient genetic divergence as by-product of local adaptations in reproductive and morphological traits to different habitats. We estimate the genetic variation and structure of populations of this species complex to assess the extent of genetic differentiation among populations and related species along its geographic distribution. Estimations of genetic diversity and structure were done based on ten enzymes and 18 loci. Mean number of alleles per locus ranged from 1.5 to 1.9. Polymorphic loci ranged from 42.1 to 68.4. Observed (H_o: range 0.191–0.275) and expected (H_e: range 0.205–0.317) heterozygosities in this complex were higher compared with other endemic and legume species. Neis genetic diversity estimates showed that most genetic variation was found within (H_S = 0.325) rather than among populations (D_ST = 0.085). Populations of the species C. hintonii showed a considerable genetic differentiation (F_ST = 0.207). The results of genetic diversity and structure within and among populations are in accord with the great morphological differentiation described for this species complex.     

Regional patterns of genetic diversity in Pinus flexilis (Pinaceae) reveal complex species history

Pinus flexilis (limber pine) is patchily distributed within its large geographic range; it is mainly restricted to high elevations in the Rocky Mountains and the Basin and Range region of western North America. We examined patterns of allozyme diversity in 30 populations from throughout the species' range. Overall genetic diversity (H(e) = 0.186) was high compared with that of most other pine species but was similar to that of other pines widespread in western North America. The proportion of genetic diversity occurring among populations (G(ST) = 0.101) was also high relative to that for other pines. Observed heterozygosity was less than expected in 28 of the 30 populations. When populations were grouped by region, there were notable differences. Those in the Basin and Range region had more genetic diversity within populations, a higher proportion of genetic diversity among populations, and higher levels of inbreeding within populations than populations from either the Northern or Utah Rocky Mountain regions. Patterns of genetic diversity in P. flexilis have likely resulted from a complex distribution of Pleistocene populations and subsequent gene flow via pollen and seed dispersal.     

Genetic differentiation in the Agave deserti (Agavaceae) complex of the Sonoran desert

The Agave deserti complex, comprising A. deserti, A. cerulata and A. subsimplex, represents a group of species and subspecies with a near allopatric distribution and clear differences in morphology. Genetic differentiation and taxonomic status with respect to spatial distribution of 14 populations of the complex were analyzed in an effort to understand the evolution and speciation process within the genus. Allelic frequencies, levels of genetic variation, expected heterozygosity (H(S)), proportion of polymorphic loci (P), and genetic differentiation (theta and Nei's genetic distance) were estimated using 41 putative RAPD loci. All three species show high levels of genetic variation (H(S)=0.12-0.29, P=63.4-95.1), and low genetic differentiation between populations and species (theta populations=0.14+/-0.02 (SE); G(st)=0.11+/-0.02). Accordingly, gene flow among populations was estimated as high by three different methods (N(m)=2.91-6.14). Nei's genetic distances between the three species were low compared to the values obtained from other Agavaceae, and there was no clear correlation with taxonomic divisions. In a UPGMA analysis, A. subsimplex and A. cerulata formed exclusive monospecific clusters, whereas the A. deserti populations appear in more than one cluster together with other species. The results were consistent with a pattern of genetic isolation by distance.     

Genetic variation and relationships among Ulex (Fabaceae) species in southern Spain and northern Morocco assessed by chloroplast microsatellite (cpSSR) markers

Genetic variation in 27 populations of Ulex species from southern Spain and northern Morocco (Betic-Rif arc) was assessed using 11 chloroplast microsatellite (cpSSR) markers, which revealed 47 different haplotypes. These nonrecombinant, haploid markers allow measurement of genetic variation in closely related species of Ulex where molecular phylogenetic analyses have not provided a clear view of interspecific relationships. Discriminant analysis indicates that the haplotypes are useful to differentiate among species, and analysis of molecular variance (AMOVA) shows high levels of differentiation among populations. The minimum spanning tree (MST), that represents the connections between the haplotypes, suggests that the eastern Rifean U. africanus haplotypes are more genetically related than those from southern Spain. The latter may have lost genetic diversity while colonizing new habitats, eventually differentiating into U. baeticus and U. scaber. Hybridization between these populations, followed by polyploidization, may have originated the tetraploids (U. congestus and U. borgiae) that colonized new habitats associated with acidic rocks. Separate groupings of U. scaber populations may indicate multiple origins from different stocks. Diversification in this group of Ulex species could be related to the opening of the Alboran Sea by Middle Miocene, when the populations from Morocco and Spain became isolated from each other.     

Pan-European phylogeography of the aquatic snail Theodoxus fluviatilis (Gastropoda: Neritidae)

Investigating the geographical distribution of genetic lineages within species is critical to our understanding of how species evolve. As many species inhabit large and complex ranges, it is important that phylogeographical research take into account the entire range of widespread species to clarify how myriad extrinsic variables have affected their evolutionary history. Using phylogenetic, nested clade, and mismatch distribution analyses on a portion of the mitochondrial COI gene, I demonstrate that the wide-ranging freshwater snail Theodoxus fluviatilis possesses in parallel many of the phylogeographical patterns seen in less widespread freshwater species of Europe. Fragmentary forces play a major part in structuring the range of this species, with 12 of 14 geographically structured nested clades displaying a distribution consistent with fragmentation or restricted dispersal. Certain regions of southern Europe harbour the majority of genetic diversity (total haplotype diversity, H = 0.87), particularly Italy (H = 0.87) and areas surrounding the Black Sea (H = 0.81). Post-Pleistocene range expansion is pronounced, with the majority of northern European populations (95% of sample sites) having arisen from northern Italian individuals that initially colonized northern Germany. Additionally, two highly divergent haplotype lineages present in northern Germany imply that there were at least two postglacial recolonization routes. Estuaries may also provide a means of dispersal given that no genetic differentiation was found between estuarine populations and neighbouring freshwater populations. Taken together, these data reveal a species with a complex genetic history resulting from the fragmentary effects of European geology as well as continuous and discrete range expansion related to their aquatic biology.     

The evolution of the Streptanthus glandulosus complex (Cruciferae): genetic divergence and gene flow in serpentine endemics

An analysis of the levels and distribution of allozyme variation in the Streptanthus glandulosus species complex was undertaken to test paradigms of speciation processes in the context of serpentine endemism. Electrophoretic analysis of 21 putative enzyme loci in 1,224 individuals representing 56 populations revealed extensive intrapopulational variation and interpopulational divergence. Estimates of gene flow among populations within taxa are typically lower than is theoretically needed to counteract the effects of genetic drift (i.e., Nm values are below 0.5), suggesting that drift may play a significant role in the evolution of the complex. A cluster analysis of genetic identities between populations using UPGMA demonstrates geographically structured groupings, some of which include neighboring populations of different taxa. Moreover, the genetic identity between two populations is correlated with the distance by which they are separated. The results are consistent with a hypothesis of a paleoendemic origin of the complex. The ancestor of the complex (perhaps S. glandulosus ssp. glandulosus) probably was formerly distributed more continuously across serpentine and nonserpentine habitat throughout its range. Elimination of the nonserpentine populations allowed regional and population-level divergence, following a model of geographic speciation.     

Molecular phylogenetics and historical biogeography of the west-palearctic common toads (Bufo bufo species complex)

In most pan-Eurasiatic species complexes, two phenomena have been traditionally considered key processes of their cladogenesis and biogeography. First, it is hypothesized that the origin and development of the Central Asian Deserts generated a biogeographic barrier that fragmented past continuous distributions in Eastern and Western domains. Second, Pleistocene glaciations have been proposed as the main process driving the regional diversification within each of these domains. The European common toad and its closest relatives provide an interesting opportunity to examine the relative contributions of these paleogeographic and paleoclimatic events to the phylogeny and biogeography of a widespread Eurasiatic group. We investigate this issue by applying a multiproxy approach combining information from molecular phylogenies, a multiple correspondence analysis of allozyme data and species distribution models. Our study includes 304 specimens from 164 populations, covering most of the distributional range of the Bufo bufo species complex in the Western Palearctic. The phylogenies (ML and Bayesian analyses) were based on a total of 1988 bp of mitochondrial DNA encompassing three genes (tRNAval, 16S and ND1). A dataset with 173 species of the family Bufonidae was assembled to estimate the separation of the two pan-Eurasiatic species complexes of Bufo and to date the main biogeographic events within the Bufo bufo species complex. The allozyme study included sixteen protein systems, corresponding to 21 presumptive loci. Finally, the distribution models were based on maximum entropy. Our distribution models show that Eastern and Western species complexes are greatly isolated by the Central Asian Deserts, and our dating estimates place this divergence during the Middle Miocene, a moment in which different sources of evidence document a major upturn of the aridification rate of Central Asia. This climate-driven process likely separated the Eastern and Western species. At the level of the Western Palearctic, our dating estimates place most of the deepest phylogenetic structure before the Pleistocene, indicating that Pleistocene glaciations did not have a major role in splitting the major lineages. At a shallow level, the glacial dynamics contributed unevenly to the genetic structuring of populations, with a strong influence in the European-Caucasian populations, and a more relaxed effect in the Iberian populations.     

Genetic assessment of species boundaries in the North American Daphnia longispina complex (Crustacea: Daphniidae)

Species boundaries in the North American Daphnia longispina group have proved difficult to establish on the basis of morphology alone. This confusion may be due to hydridization, phenotypic plasticity or the existence of sibling species. We therefore used genetic analysis to delineate species boundaries by examining 27 North American populations belonging to the longispina complex for variation at 15–26 allozyme loci. The populations consisted of Daphnia thorata from two western sites and two eastern sites, Daphnia galeata mendotae from its type location and seven sites across its range, and Daphnia rosea from eight temperate and seven arctic sites. Two populations from the Eurasian longispina complex were also included for reference. Populations assigned to D. galeata mendotae formed a genetically cohesive group, whereas a genetic dichotomy was found between temperate and arctic D. rosea , suggesting that this taxon includes two species. Genetic analysis also confirmed the distinctness of western D. thorata from other members of the longispina group. Unexpectedly, eastern populations resembling D. thorata were genetically more similar to temperate D. rosea than to any helmeted species ( D. galeata, Daphnia hyalina or D. thorata ). Our results suggest that the helmet character is a poor indicator of phylogenetic relationships, as the genetic ability to produce this feature has been lost or acquired several times in the evolution of the longispina group.     

High genetic differentiation of Aegla longirostri (Crustacea, Decapoda, Anomura) populations in southern Brazil revealed by multi-loci microsatellite analysis

Species with a broad distribution rarely have the same genetic make-up throughout their entire range. In some cases, they may constitute a cryptic complex consisting of a few species, each with a narrow distribution, instead of a single-, widely distributed species. These differences can have profound impacts for biodiversity conservation planning. The genetic differentiation of four populations of Aegla longirostri, a freshwater crab found in two geographically isolated basins in Rio Grande do Sul State, Brazil, was investigated by analyzing pentanucleotide multi-loci microsatellites in a heteroduplex assay. Although no morphological differences were evident, we found significant genetic differentiation among the four populations, based on F(ST) values and clustering analysis. This high level of differentiation may be indicative of cryptic species in these populations. If this hypothesis is correct, then the species occurring in the Ibicuí-Mirim River, at the southern limit of the Atlantic Rain Forest, would be under threat, considering its very restricted distribution.     

Genetic diversity among Zygophyllum (Zygophyllaceae) populations based on RAPD analysis

Zygophyllum species are succulent plants that are drought resistant and/or salt tolerant, growing under severe, dry climatic conditions. Despite their importance and abundance in the Mediterranean and Middle East regions, there is little information concerning molecular variations among species of this genus. Genetic diversity was assessed, using RAPD primers, of 12 populations of Z. coccineum, Z. album and Z. aegyptium collected from various locations in Egypt and Saudi Arabia. Yong leaves were used for DNA extraction. Genetic distances were calculated using Nei's method. A dendrogram was constructed based on the similarity data matrix by unweighted pair group method using arithmetic averages cluster analysis. Analysis with RAPD markers revealed genetic variation between and within populations of Zygophyllum. Zygophyllum coccineum showed higher levels of genetic variation and more unique alleles than the other species.