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1.
To help clarify controversial phylogenetic relationships within the family Emberizidae, we sequenced 1238 bp of mitochondrial DNA from the cytochrome b gene and a flanking portion of ND5. Although the longspurs ( Calcarius ) and the snow buntings ( Plectrophenax ) have been grouped with the Old World buntings ( Emberiza ) in traditional classifications, our molecular phylogenies constructed with maximum likelihood and maximum parsimony place these genera basal to a clade in which the Old World buntings and North American sparrows are sister groups. Contrary to the hypothesis that the radiation within Emberiza is recent following a westward expansion of emberizid stock into Eurasia from North America, we found that the level of genetic divergence among Old World buntings approximates those among different genera in North American sparrows. Thus the radiation of the Emberizidae seems to have occurred at roughly the same time in the Palaearctic and Nearctic. Our results are consistent with earlier analyses of allozymes, but sequences from multiple genes and new morphological analyses are required to fully resolve phylogenetic relationships within the Emberizidae.  相似文献   

2.
To investigate the phylogenetic relationships between the New World Sciurus and the Old World Sciurus and their biogeographic history, the partial mitochondrial cytochrome b gene sequences (1,040 base pairs) were analyzed on six Sciurus species: S. aberti, S. carolinensis, S. lis, S. niger, S. stramineus, and S. vulgaris. Phylogenetic trees (maximum parsimony, neighbor-joining, and maximum likelihood methods) commonly showed two groups with high bootstrap values (73-100%): one consisting of the New World Sciurus and the other consisting of the Old World Sciurus. Genetic distances among the New World Sciurus species were remarkably larger than that between two Sciurus species of the Old World, suggesting the earlier radiation of the New World Sciurus than the Old World Sciurus.  相似文献   

3.
The phylogeny of the avian genus Emberiza and the monotypic genera Latoucheornis, Melophus and Miliaria (collectively the Old World Emberizini), as well as representatives for the New World Emberizini, the circumpolar genera Calcarius and Plectrophenax and the four other generally recognized tribes in the subfamily Emberizinae was estimated based on the mitochondrial cytochrome b gene and introns 6-7 of the nuclear ornithine decarboxylase (ODC) gene. Our results support monophyly of the Old World Emberizini, but do not corroborate a sister relationship to the New World Emberizini. Calcarius and Plectrophenax form a clade separated from the other Emberizini. This agrees with previous studies, and we recommend the use of the name Calcariini. Latoucheornis, Melophus and Miliaria are nested within Emberiza, and we therefore propose they be synonymized with Emberiza. Emberiza is divided into four main clades, whose relative positions are uncertain, although a sister relation between a clade with six African species and one comprising the rest of the species (30, all Palearctic) is most likely. Most clades agree with traditional, morphology-based, classifications. However, four sister relationships within Emberiza, three of which involve the previously recognized Latoucheornis, Melophus and Miliaria, are unpredicted, and reveal cases of strong morphological divergence. In contrast, the plumage similarity between adult male Emberiza (formerly Latoucheornis) siemsseni and the nominate subspecies of the New World Junco hyemalis is shown to be the result of parallel evolution. A further case of parallel plumage evolution, between African and Eurasian taxa, is pointed out. Two cases of discordance between the mitochondrial and nuclear data with respect to branch lengths and genetic divergences are considered to be the result of introgressive hybridization.  相似文献   

4.
Species of the genus Antirrhinum (Veronicaceae) provide excellent opportunities for research on plant evolution given their extensive morphological and ecological diversity. These opportunities are enhanced by genetic and developmental data from the model organism Antirrhinum majus. The genus Antirrhinum includes 15 New World species in section Saerorhinum and 21 Old World species in sections Antirrhinum and Orontium. Phylogenetic analyses of sequences of the internal transcribed spacer region (ITS) of nuclear ribosomal DNA were conducted for 19 Antirrhinum species, including all species from the New World, and 13 related genera in the tribe Antirrhineae. These analyses confirm the monophyly of Antirrhinum given the inclusion of the small genus Mohavea and exclusion of A. cyathiferum. The New World species, all of which are tetraploid, form a clade that is weakly supported as sister to the Old World sect. Orontium. The Old World species in sect. Antirrhinum form a well-supported clade that is sister to the remainder of the genus. In addition, both molecular and morphological data are used in the most comprehensive effort to date focused on recovering the phylogenetic relationships among the extremely diverse species in section Saerorhinum.  相似文献   

5.
Kruckenhauser, L., Haring, E., Pinsker, W., Riesing, M. J., Winkler, H., Wink, M. & Gamauf, A. (2004). Genetic vs. morphological differentiation of Old World buzzards (genus Buteo , Accipitridae). — Zoologica Scripta , 33 , 197–211.
Here, a comprehensive phylogenetic investigation of Old World buzzards of the buteo–vulpinus complex and related taxa using morphological and genetic markers is presented. The morphometric analysis proved useful to discriminate taxa. Nevertheless, phylogenetic relationships cannot be resolved with these characters. Sequence comparisons between the control region and the pseudo-control region revealed that the latter is the most variable section of the mitochondrial genome. Consequently it was used as a marker sequence. In the genetic analysis, almost no sequence variability was found among taxa comprising the buteo–vulpinus complex as well as Buteo rufinus and Buteo oreophilus , suggesting gene flow and/or incomplete lineage sorting. Thus, rapid morphological differentiation in adaptation to different environments was not accompanied by genetic differentiation of the mitochondrial genomes of these taxa. In contrast, the East Palearctic taxa are well differentiated genetically. The 'superspecies' concept and taxonomic consequences of our results are discussed.  相似文献   

6.
? Premise of the study: The Malpighiaceae include ~1300 tropical flowering plant species in which generic definitions and intergeneric relationships have long been problematic. The goals of our study were to resolve relationships among the 11 generic segregates from the New World genus Mascagnia, test the monophyly of the largest remaining Malpighiaceae genera, and clarify the placement of Old World Malpighiaceae. ? Methods: We combined DNA sequence data for four genes (plastid ndhF, matK, and rbcL and nuclear PHYC) from 338 ingroup accessions that represented all 77 currently recognized genera with morphological data from 144 ingroup species to produce a complete generic phylogeny of the family. ? Key results and conclusions: The genera are distributed among 14 mostly well-supported clades. The interrelationships of these major subclades have strong support, except for the clade comprising the wing-fruited genera (i.e., the malpighioid+Amorimia, Ectopopterys, hiraeoid, stigmaphylloid, and tetrapteroid clades). These results resolve numerous systematic problems, while others have emerged and constitute opportunities for future study. Malpighiaceae migrated from the New to Old World nine times, with two of those migrants being very recent arrivals from the New World. The seven other Old World clades dispersed much earlier, likely during the Tertiary. Comparison of floral morphology in Old World Malpighiaceae with their closest New World relatives suggests that morphological stasis in the New World likely results from selection by neotropical oil-bee pollinators and that the morphological diversity found in Old World flowers has evolved following their release from selection by those bees.  相似文献   

7.
Picoides is the largest genus of woodpeckers and member species are found on most major land masses. Current systematic arrangement of this group, based on morphological, behavioral, and plumage characters, suggests that New World species evolved from a single invasion by a Eurasian common ancestor and that all New World species form a monophyletic group. No clear link has ever been established between the relationships of Old World and New World species other than to infer that the most primitive species is Eurasian. This study employs DNA sequences for two protein-coding mitochondrial genes, cytochrome oxidase I and cytochrome b, to reconstruct phylogenetic relationships among all New World species and several Eurasian representatives of the genus Picoides. A well-resolved mitochondrial gene tree is in direct conflict with proposed species relationships based on nongenetic characters; monophyly among New World species is rejected, the evolution of New World species likely resulted from as many as three independent Eurasian invasions, and Picoides is paraphyletic with two other woodpecker genera, Veniliornis and Dendropicos. These results strongly suggest that this large, cosmopolitan genus is in need of systematic revision in order to reflect evolutionary history.  相似文献   

8.
Patterns of colonization and diversification on islands provide valuable insights into evolutionary processes. Due to their unique geographic position and well known history, the Galapagos Islands are an important model system for evolutionary studies. Here we investigate the evolutionary history of a winged grasshopper genus to infer its origin and pattern of colonization in the Galapagos archipelago. The grasshopper genus Sphingonotus has radiated extensively in the Palaearctic and many species are endemic to islands. In the New World, the genus is largely replaced by the genus Trimerotropis. Oddly, in the Caribbean and on the Galapagos archipelago, two species of Sphingonotus are found, which has led to the suggestion that these might be the result of anthropogenic translocations from Europe. Here, we test this hypothesis using mitochondrial and nuclear DNA sequences from a broad sample of Sphingonotini and Trimerotropini species from the Old World and New World. The genetic data show two distinct genetic clusters representing the New World Trimerotropini and the Old World Sphingonotini. However, the Sphingonotus species from Galapagos and the Caribbean split basally within the Old World Sphingonotini lineage. The Galapagos and Caribbean species appear to be related to Old World taxa, but are not the result of recent anthropogenic translocations as revealed by divergence time estimates. Distinct genetic lineages occur on the four investigated Galapagos Islands, with deep splits among them compared to their relatives from the Palaearctic. A scenario of a past wider distribution of Sphingonotus in the New World with subsequent extinction on the mainland and replacement by Trimerotropis might explain the disjunct distribution.  相似文献   

9.
Sequences of the nuclear ribosomal DNA internal transcribed spacer region 1 and the chloroplast-encoded genes maturase K and ribulose-1,5 biphosphate carboxylase large subunit were obtained from species of Ephedra (Ephedraceae) representing the geographic range and morphological diversity of the genus. Phylogenetic analyses of the DNA data indicate that relationships within the genus are better predicted by geographic region of origin than by ovulate cone characters. The sampled species with dry, winged (versus fleshy) ovulate cone bracts or single-seeded cones do not form monophyletic groups and therefore the previous classification systems of Ephedra based on these aspects of bract morphology appear to be largely unnatural. Three groups were identified among the Old World species studied, one comprising European and Mediterranean species and two including only Asian species. The sequence data suggest a possible early divergence of a New World clade of Ephedra from among the Old World groups. The South American species form a distinct clade apparently related to one of two groups of North American species, which accords with a frequent floristic pattern of close relationships between species groups in western South America and southwestern North America.  相似文献   

10.
Eryngium is the largest and arguably the most taxonomically complex genus in the family Apiaceae. Infrageneric relationships within Eryngium were inferred using sequence data from the chloroplast DNA trnQ-trnK 5'-exon and nuclear ribosomal DNA ITS regions to test previous hypotheses of subgeneric relationships, explain distribution patterns, reconstruct ancestral morphological features, and elucidate the evolutionary processes that gave rise to this speciose genus. In total, 157 accessions representing 118 species of Eryngium, 15 species of Sanicula (including the genus Hacquetia that was recently reduced to synonymy) and the monotypic Petagnaea were analyzed using maximum parsimony and Bayesian methods. Both separate and simultaneous analyses of plastid and nuclear data sets were carried out because of the prevalence of polyploids and hybrids within the genus. Eryngium is confirmed as monophyletic and is divided into two redefined subgenera: Eryngium subgenus Eryngium and E. subgenus Monocotyloidea. The first subgenus includes all examined species from the Old World (Africa, Europe, and Asia), except Eryngium tenue, E. viviparum, E. galioides, and E. corniculatum. Eryngium subgenus Monocotyloidea includes all examined species from the New World (North, Central and South America, and Australia; herein called the "New World sensu stricto" clade) plus the aforementioned Old World species that fall at the base of this clade. Most sectional and subgeneric divisions previously erected on the basis of morphology are not monophyletic. Within the "New World sensu stricto" group, six clades are well supported in analyses of plastid and combined plastid and nuclear data sets; the relationships among these clades, however, are unresolved. These clades are designated as "Mexican", "Eastern USA", "South American", "North American monocotyledonous", "South American monocotyledonous", and "Pacific". Members of each clade share similar geographical distributions and/or morphological or ecological traits. Evidence from branch lengths and low sequence divergence estimates suggests a rapid radiation at the base of each of these lineages. Conflict between chloroplast and nuclear data sets is weak, but the disagreements found are suggestive that hybrid speciation in Eryngium might have been a cause, but also a consequence, of the different rapid radiations observed. Dispersal-vicariance analysis indicates that Eryngium and its two subgenera originated from western Mediterranean ancestors and that the present-day distribution of the genus is explained by several dispersal events, including one trans-Atlantic dispersal. In general, these dispersals coincide with the polytomies observed, suggesting that they played key roles in the diversification of the genus. The evolution of Eryngium combines a history of long distance dispersals, rapid radiations, and hybridization, culminating in the taxonomic complexity observed today in the genus.  相似文献   

11.
Studies of phylogenetic relationships among cypresses of the Old World (Cupressus; Cupressaceae) have been plagued by unresolved relationships, poor branch support, and conflict between data sets and methods of analysis. In this study, we combined 5.4 kb of aligned DNA sequence and 157 binary characters with previously published data in examining phylogenetic relationships among Cupressus species. Bayesian and parsimony analysis of the combined data or of the nuclear data alone always recovered three principal clades of Cupressus; however, tests of phylogenetic incongruence could not distinguish between competing relationships among the three principal Cupressus lineages. In contrast, incongruence tests often found statistically significant conflict between the nuclear and plastid data, particularly with respect to the placement of C. chengiana. Consistent with previous studies and prevailing taxonomic opinion, we find C. darjeelingensis more closely related to cypresses of the New World (Hesperocyparis). In contrast, we placed accessions of C. assamica and C. tonkinensis, two putatively Old World species suggested to be misidentified New World taxa by some authors, within well-supported Old World clades. Statistical analysis of genetic distances suggests instances in which taxa recognized as distinct species by some authors are identical or nearly so and may best be considered a single taxon. Conversely, we identify instances in which infraspecific taxa are more distantly related to one another than those traditionally recognized as distinct species. Factors confounding cypress taxonomies, including poor morphological differentiation, misidentification, and the use of accessions of questionable provenance, are discussed.  相似文献   

12.
Extant bats of the genus Emballonura have a trans-Indian Ocean distribution, with two endemic species restricted to Madagascar, and eight species occurring in mainland southeast Asia and islands in the western Pacific Ocean. Ancestral Emballonura may have been more widespread on continental areas, but no fossil identified to this genus is known from the Old World. Emballonura belongs to the subfamily Emballonurinae, which occurs in the New and Old World. Relationships of all Old World genera of this subfamily, including Emballonura and members of the genera Coleura from Africa and western Indian Ocean islands and Mosia nigrescens from the western Pacific region, are previously unresolved. Using 1833 bp of nuclear and mitochondrial genes, we reconstructed the phylogenetic history of Old World emballonurine bats. We estimated that these lineages diverged around 30 million years ago into two monophyletic sister groups, one represented by the two taxa of Malagasy Emballonura, Coleura and possibly Mosia, and the other by a radiation of Indo-Pacific Emballonura, hence, rendering the genus Emballonura paraphyletic. The fossil record combined with these phylogenetic relationships suggest at least one long-distance dispersal event across the Indian Ocean, presumably of African origin, giving rise to all Indo-Pacific Emballonura species (and possibly Mosia). Cladogenesis of the extant Malagasy taxa took place during the Quaternary giving rise to two vicariant species, E. atrata in the humid east and E. tiavato in the dry west.  相似文献   

13.
Elucidating the evolution of Phlebotominae is important not only to revise their taxonomy, but also to help understand the origin of the genus Leishmania and its relationship with humans. Our study is a phenetic portrayal of this history based on the genetic relationships among some New Word and Old Word taxa. We used both multilocus enzyme electrophoresis and morphometry on 24 male specimens of the Old Word genus Phlebotomus (with three of its subgenera: Phlebotomus, Spelaeophlebotomus and Australophlebotomus), and on 67 male specimens of the three New World genera, Warileya, Brumptomyia and Lutzomyia, (with three subgenera of Lutzomyia: Lutzomyia, Oligodontomyia and Psychodopygus). Phenetic trees derived from both techniques were similar, but disclosed relationships that disagree with the present classification of sand flies. The need for a true evolutionary approach is stressed.  相似文献   

14.
Salvia, with over 900 species from both the Old and New World, is the largest genus in the Lamiaceae. Unlike most members of the subfamily Nepetoideae to which it belongs, only two stamens are expressed in Salvia. Although the structure of these stamens is remarkably variable across the genus, generally each stamen has an elongate connective and divergent anther thecae, which form a lever mechanism important in pollination. In a preliminary investigation of infrageneric relationships within Salvia, the monophyly of the genus and its relationship to other members of the tribe Mentheae were investigated using the chloroplast DNA regions rbcL and trnL-F. Significant conclusions drawn from the data include: Salvia is not monophyletic, Rosmarinus and Perovskia together are sister to an Old World clade of Salvia, the section Audibertia is sister to subgenus Calosphace or the monotypic Asian genus Dorystaechas, and the New World members of section Heterosphace are sister to section Salviastrum. Owing to the non-monophyly of Salvia, relationships at the next clearly monophyletic level, tribe Mentheae, were investigated.  相似文献   

15.
An electrophoretic analysis of 12 allozyme systems (14 loci, 40 alleles) was performed in the rodent genera Oryzomys and Oligoryzomys, in order to determine the levels of genetic variability within and among populations and species. One hundred and fifty-five individuals from 16 populations of Oryzomys russatus, Or. angouya, Oligoryzomys flavescens, and O1. nigripes species were trapped in nine Brazilian localities. Genetic divergence among populations, as well as the interpopulational gene diversity, was higher in Oryzomys than in Oligoryzomys. The dendrogram of the phenetic relationships among the 16 populations of these four species displays three clusters: the first one joins the O1. flavescens populations with those of O1. nigripes; the second groups the populations of Or. russatus, and the last assembles the populations of Or. angouya. The genetic parameters analyzed reveal that the species belonging to the genus Oryzomys are genetically more structured than those of Oligoryzomys, the latter presenting lower levels of intrademe genetic differentiation (G(ST)')  相似文献   

16.
Four protein-encoding mitochondrial genes (cytochrome b , NADH-dehydrogenase subunits 1, 2 and 4) and one nuclear (c-mos) gene were sequenced to infer phylogenetic relationships among Old and New World representatives of racers and whipsnakes, Coluber (sensu lato). New World Coluber ( Coluber sensu stricto, including Masticophis ) and Salvadora proved to have affinities with the Old World non-racer colubrine genus Ptyas (and possibly Elaphe s.l. and Coronella ), whereas Old World ' Coluber ' form several basally related clades; these are (1) Hemorrhois -( Spalerosophis-Platyceps ); (2) Hierophis , with Eirenis nested within this paraphyletic genus and (3) ' Coluber ' dorri as the sister taxon to Macroprotodon cucullatus . The position of ' Coluber ' zebrinus along with Hemerophis socotrae located at the base of the Old World racer radiation forming the possible sister group to all remaining Palearctic racers and whipsnakes remains less well supported. Nevertheless, inter- and subgeneric relationships among many of the Old World racer groups have been resolved.  相似文献   

17.
18.
Genetic distances between eight species of sousliks (Spermophilus) and five species of marmots (Marmota) were estimated on the basis of 39 biochemical loci. All taxa were shown to be genetically discrete. The genetic differentiation was minimal (Pfd = 11.3) between parapatric species of Palearctic sousliks of the suslicus pigmaeus group and Marmota species, intermediate (Pfd = 34.7) between allopatric sousliks species, and maximal (Pfd = 56.7) between representatives of different genera. The following trends were revealed in the geographic differentiation of the genus Spermophilus: (1) genetic similarity was associated with the geographic distance; (2) the eastern and western Palearctic phyla were markedly different genetically; (3) the eastern Palearctic forms exhibited higher differentiation than the western ones. The revealed speciation pattern is consistent with the general trend of temporal differentiation in Palearctic phyla and confirms the periodic speciation mode in the Palearctics.  相似文献   

19.
Urine collected from New World monkeys (tufted capuchin, squirrel monkey, cotton-top tamarin) and Old World monkeys (rhesus macaque, Japanese macaque), was used as the odor stimuli. Two adult tufted capuchins were trained on a successive odor-discrimination task with two odors, 30 trials each, in one session per day. Responses to one of the two odors (S+) were reinforced by sweet water. The monkeys failed to discriminate between the urine from the two species of macaques but could discriminate among the urine from the three species of New World monkeys. Furthermore, similarity of urine odors was analyzed by multi-dimensional scaling (MDS) and a cluster analysis. These analysis suggested that the tufted capuchin can distinguish differences among New World monkeys but not between the macaques. The natural distribution of the tufted capuchin overlaps with that of other New World monkeys, but it does not overlap with those of Old World monkeys. Consequently, it can be concluded that this difference in olfactory recognition in the tufted capuchin reflects their sympatric and allopatric relationships with other species.  相似文献   

20.
In this study, 30 microsatellite markers recommended by the International Society for Animal Genetics and the Food and Agriculture Organization were used to determine the extent of genetic differentiation and phylogenetic relationships among indigenous chicken populations sampled in Kenya, Uganda, Ethiopia and Sudan. Genetic differentiation (F(ST)) and chord genetic distances (D(C)) indicated that the indigenous chickens were genetically related but distinct from commercial broiler and egg layer lines. Genetic divergence among the indigenous chickens determined using the Mantel test was significantly influenced (P < 0.001) by geographic (reproductive) isolation. Genetic subdivisions were found between the Kenyan/Ugandan chicken populations and Ethiopian/Sudanese chicken populations. The Marsabit chicken population from northern Kenya was the most genetically distinct population within the Kenyan and Ugandan chicken cluster, thus warranting further investigation.  相似文献   

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