Allozyme diversity within and divergence among species ofTolpis(Asteraceae-Lactuceae) in the Canary Islands: systematic, evolutionary, and biogeographical implications

Plants endemic to oceanic islands represent some of the most unusual and rare taxa in the world. Enzyme electrophoresis was used to assess genetic diversity within and divergence among all endemic species of a small genus of plants on the Canary Islands. Our results show that the genus Tolpis is similar to many other island groups in having generally low allozyme divergence among species, with the highest divergence found among four groups of endemics. The two rare and highly localized species T. glabrescens and T. crassiuscula are each divergent from all other species in the Canaries. Tolpis coronopifolia is also divergent at allozyme loci; this is the only endemic species that is a self-compatible annual (or weak biennial). A large, morphologically variable species complex consisting of T. laciniata and T. lagopoda together with several named and unnamed morphological variants shows low allozyme divergence among its elements. The evolution of polyploidy from diploid ancestors in situ in oceanic archipelagos is uncommon, but the tetraploid T. glabrescens is an exception. Allozyme data do not implicate any extant diploid Tolpis species as parents of the polyploid. It is possible that T. glabrescens originated early in the evolution of Tolpis in the Canary Islands and that its parents are now extinct. The nonendemic T. barbata shows no greater divergence from the Canary Island endemics than some endemics exhibit among themselves. Both changes in allele frequencies and unique alleles are responsible for genetic divergence among species of Tolpis.     

Phylogenetic investigation of the genus Raoiella (Prostigmata: Tenuipalpidae): diversity, distribution, and world invasions

The genus Raoiella is best known because of the red palm mite, R. indica, a major pest of palms spreading aggressively throughout the Americas. Not much was known about the biology, geographic origins, or evolutionary history of the genus when R. indica emerged as a major invasive pest. This paper attempts to address some of the basic historical questions regarding the palm mite as well as the genus. Molecular characters from COI and 28S regions were used to produce a phylogenetic hypothesis for the genus in an effort to understand its geographic origin. It also uses COI barcode data to delimit several potentially new species discovered by the authors in Australia. Results show a basal split between R. indica and all other Raoiella species, which indicates Africa or the Middle East as the most probable origin of the genus. Additionally, COI data suggests that at least eight new species are represented among the 20 Australian populations included in this study.     

Evolutionary processes in the genus Coreocarpus: insights from molecular phylogenetics

A molecular phylogenetic study of the plant genus Coreocarpus was conducted using nuclear (ITS) and plastid (rpl16 intron) DNA sequences, with phylogenies of the nuclear and plastid sequences highly congruent in defining a monophyletic group of six species (core Coreocarpus), although three other species often placed within the genus were excluded. Relationships within the genus are largely but not totally concordant with prior biosystematic studies. Despite strong molecular support, no morphological characters uniting the six species of core Coreocarpus have been identified; retention of plesiomorphic characters and the genetic lability of characters are two probable factors contributing to lack of consistent defining characters. The age of the core Coreocarpus is estimated at 1 million years because the basal species is endemic to a volcanic island that emerged in the past million years. Mapping the results of earlier breeding studies on the molecular phylogeny showed that use of cross-compatibility as a criterion for species delimitation would result in the recognition of paraphyletic species. Prior field, morphological, and biosystematic studies provided no indication of past hybridization in the evolution of Coreocarpus, and species in the genus appeared to be well defined morphologically. However, three instances of incongruence were observed. Two of these were between the nuclear and plastid partitions, and the third was between the morphological species assignment of one accession and the molecular data. If hybridization accounts for incongruence between the nuclear and plastid data, it occurred between species that now appear to be cross-incompatible and allopatric. The incongruence between morphological species assignment and the molecular data could be the result of parallel fixation of characters that have a simple genetic basis. This study suggests that the evolutionary history of Coreocarpus is much more complex than indicated from prior biosystematic investigations and that biosystematic and molecular phylogenetic studies may complement each other for elucidating the evolution and phylogeny of a group.     

Molecular phylogenetics and ecological diversification of the transisthmian fish genus Centropomus (Perciformes: Centropomidae).

Phylogenetic relationships among the 12 recognized fish species in the New World genus Centropomus (Pisces, Centropomidae) were analyzed using allozyme electrophoresis and 618 bp of the mitochondrial DNA 16S ribosomal RNA (rRNA) gene. Molecular phylogenetic trees were generally consistent with previously published partial hypotheses based on morphological evidence. However, previously undefined sister group relationships between major species groups were resolved using molecular data, and phylogenetic hypotheses for Centropomus based on 16S rRNA sequences were better supported than were allozyme-based hypotheses. The high level of congruence among the trees inferred from the nuclear and mitochondrial characters provided a firm phylogenetic basis for analysis of ecological diversification and molecular evolution in the genus. Compared to basal Centropomus species, members of the most nested species group were significantly larger in body size and occupied a marine niche only peripherally utilized by their congeners. We also observed substitution rate heterogeneity among 16S rRNA lineages; in contrast to expectations based on "metabolic rate" and "generation interval" models, relative substitution rates were faster than expected for the group of large-bodied snooks. Using the Pliocene rise of the Central American isthmian marine barrier to calibrate rates of 16S ribosomal gene evolution in Centropomus, we found that the rates for the genus were similar to those reported for higher vertebrates. Analysis of the three sets of transisthmian geminate taxa in Centropomus indicated that two of the pairs were probably formed during the Pliocene rise of the isthmus while the third pair diverged several million years earlier.     

Delimitation of morphologically similar sponge crab species of the genus Pseudodromia (Crustacea, Decapoda, Dromiidae) from South Africa

Stewart, B. A., Gouws, G., Daniels, S. R. & Matthee, C. A. (2004). Delimitation of morphologically similar sponge crab species of the genus Pseudodromia (Crustacea, Decapoda, Dromiidae) from South Africa. — Zoologica Scripta , 33 , 45–55.
Presently, three Pseudodromia sponge crab species are recognized, all of which are endemic to the continental shelf off the coast of South Africa. Two of these differ only in the morphology of their rostral teeth, making them difficult to distinguish, and can thus be considered as cryptic species. In addition they have very similar distribution ranges, thus raising doubts as to their specific status. Discriminant function analysis of morphometric data, differentiation at 10 allozyme loci, and sequence data derived from the 12S rRNA mitochondrial gene were used to test whether specimens identified as P. latens and P. rotunda are morphological forms of a single, widespread species, or represent two, distinct, reproductively isolated species, and to establish whether these two taxa are sister species, and thus form a monophyletic entity. The presence of fixed allele differences at three, and strong genetic heterogeneity at five other allozyme loci, indicating no gene flow occurring between sympatric populations, as well as the relatively high degree of 12S rRNA and allozyme genetic differentiation observed, supported the recognition of P. latens and P. rotunda as separate species. The 12S rRNA topology suggested that the genus Pseudodromia , as presently constituted, is paraphyletic, thus inferring that the morphological characters used to define this taxon might not be useful for phylogenetic inferences. It was concluded that in view of the uncertainties raised regarding the designation and composition of certain genera within the family Dromiidae, further rigorous analyses of morphological and genetic data are needed to further our understanding of the taxonomy of the sponge crabs.     

The phylogeny of Halgerda (Opisthobranchia, Nudibranchia) with the description of a new species from Okinawa

This paper proposes a refined hypothesis of evolution for the tropical Indo-Pacific nudibranch genus Halgerda . Numerous specimens from 31 species were examined anatomically and literature from four additional species was reviewed, bringing to 33 the ingroup taxa. Fifty-three characters were considered from these examinations. The outgroup Asteronotus was used to polarize the characters. The phylogeny obtained from the analysis of the characters supports the hypothesis that Halgerda is a monophyletic group. A species previously placed with the genus Sclerodoris is examined and determined to be a member of the genus Halgerda . Phylogenetic analysis places this species, H. paliensis , as a basal member of the genus . Halgerda paliensis appears to be restricted to the Hawaiian Islands. Specimens previously identified as Sclerodoris paliensis from the Marshall Islands actually represent H. dalanghita Fahey & Gosliner, 1999. A new species, Halgerda onna , is described and presented as the sister taxon to a basal member of the genus. A range and depth extension of a previously described species, H. malesso , is presented. The present phylogeny is then compared to previous studies, in particular those of Fahey & Gosliner (1999a,b) .     

Divergence in locomotor performance,ecology, and morphology between two sympatric sister species of desert‐dwelling gecko

The functional and evolutionary implications of morphological diversification have been addressed for several groups of vertebrates. Although the mechanisms of gecko adhesion have received considerable attention, little is known regarding locomotor performance of geckos in nature, and how this might relate to morphological diversity. In this study we examine locomotor performance of two sympatric sister species of geckos of the genus Rhoptropus (Rhoptropus afer and Rhoptropus bradfieldi) found in the coastal desert regions of Namibia. One species (R. afer) commonly runs on sandy substrates and moves between isolated rock sheets, whereas the other species (R. bradfieldi) commonly lives and runs on isolated boulders. The morphology of R. afer is extremely divergent from its sister species and all other species in the genus. We initially recorded the inclination of the substrate in which the lizards were found in order to characterize the habitat of each species. We then quantified maximum speed and acceleration on a level 1‐m trackway, and also during escapes in the field. We found that R. bradfieldi occupies steeper surfaces than those occupied by R. afer. On the trackway and in nature, R. afer runs faster than R. bradfieldi, although the differences in locomotor performance between the species are greater for the field measurements. Rhoptropus afer commonly runs for more than 2 or 3 m, whereas R. bradfieldi commonly runs less than 50 cm during an escape sprint. Our main conclusions are that: (1) R. afer attains higher maximum speeds when escaping under controlled and field conditions, although the magnitude differs between conditions; and (2) hindlimb morphology correlates with maximum running speed in R. afer, but not in R. bradfieldi. Similar to the well‐studied Anolis lizards, we propose that these two gecko species represent distinct and highly divergent ecomorphs. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 101 , 860–869.     

6种毛茛属植物的等位酶变异和亲缘关系分析

用聚丙烯酰胺凝胶垂直平板电泳检测了6种毛良属(Ranunculus Linn．)植物4个酶系统的等位酶谱带变异式样,并将酶谱带的二忿数据进行相关分析和聚类分析,结果表明：有93．94％的等位酶谱带在6个种之间显示出或多或少的变异,只有6．06％的等位酶谱带在6个种中保持恒定。相关分析和聚类分析显示,同种内个体间表现出较大的遗传同质性;而不同种的个体则表现出明显的趋异性。表明6种植物之间遗传分化较明显．并按聚类结果将6个种划分为两个类群．水城毛茛和毛茛为一个类群;扬子毛茛、褐鞘毛茛、钩柱毛茛和棱喙毛茛为一个类群。其中,扬子毛茛和棱喙毛良之间的亲缘关系最近。毛茛和褐鞘毛茛之间的亲缘关系最远。     

Morphological, cytogenetic and allozymic variation within Cephalofovea (Onychophora: Peripatopsidae) with descriptions of three new species

Variation within and between populations of Cephalofovea (Peripatopsidae) has been examined by allozyme, karyological and morphological analyses. Four groups are recognized on the basis of allozyme electrophoresis. One group includes specimens from the type locality of the only described species of the genus, C. tomahmontis. While karyotypic and morphological character states show considerable inter-group variation, the distributions of these states among groups are not concordant when different characters are compared. However, each group of populations is uniquely defined by the full suite of character states it possesses. The four groups are recognized here as distinct species with three species described as new.     

Evolution of the Mitochondrial Cytochrome Oxidase II Gene in Collembola

The sequence of the mitochondrial COII gene has been widely used to estimate phylogenetic relationships at different taxomonic levels across insects. We investigated the molecular evolution of the COII gene and its usefulness for reconstructing phylogenetic relationships within and among four collembolan families. The collembolan COII gene showed the lowest A + T content of all insects so far examined, confirming that the well-known A + T bias in insect mitochondrial genes tends to increase from the basal to apical orders. Fifty-seven percent of all nucleotide positions were variable and most of the third codon positions appeared free to vary. Values of genetic distance between congeneric species and between families were remarkably high; in some cases the latter were higher than divergence values between other orders of insects. The remarkably high divergence levels observed here provide evidence that collembolan taxa are quite old; divergence levels among collembolan families equaled or exceeded divergences among pterygote insect orders. Once the saturated third-codon positions (which violated stationarity of base frequencies) were removed, the COII sequences contained phylogenetic information, but the extent of that information was overestimated by parsimony methods relative to likelihood methods. In the phylogenetic analysis, consistent statistical support was obtained for the monophyly of all four genera examined, but relationships among genera/families were not well supported. Within the genus Orchesella, relationships were well resolved and agreed with allozyme data. Within the genus Isotomurus, although three pairs of populations were consistently identified, these appeared to have arisen in a burst of evolution from an earlier ancestor. Isotomurus italicus always appeared as basal and I. palustris appeared to harbor a cryptic species, corroborating allozyme data. Received: 12 January 1996 / Accepted: 10 August 1996     

POSTGLACIAL RANGE FLUCTUATION,GENETIC SUBDIVISION AND SPECIATION IN THE WESTERN NORTH AMERICAN SPOTTED FROG COMPLEX,RANA PRETIOSA

The western North American complex of spotted frogs (Rana pretiosa) exhibits isolation-by-distance, genetic subdivision, and speciation in association with its extensive northward range shift in postglacial times. The southern relict populations of R. pretiosa species B existing at high altitudes or in desert springs have been subjected to restricted gene flow, high inbreeding, and bottlenecks to produce significant between-population genetic diversity. The more recently established northern populations, however, show genetic uniformity and isolation-by-distance, as estimated using Slatkin's (1993) statistic M?. Middle latitude populations have higher heterozygosities than populations at either extreme. Fixed differences in allozyme variation separate 21 populations of species B from five populations of R. pretiosa species A found in southwest Washington State and the Cascades Mountains of Oregon. Morphological variation of 20 metric characters among 38 samples, examined using multiple discriminant function analysis, could partially resolve partitioning among populations but specimens from the vicinity of the type series of R. p. pretiosa could not be assigned to either species A or species B. Speciation in these frogs may not be correlated with morphological evolution since comparatively neutral allozyme changes may be established more rapidly than changes in morphology.     

High allozyme variation in populations of three spiny rat species from Upper Amazonia: association with ecology and evolution]

The allozyme variation in three spiny rat species of the genus Proechimys from Upper Amazonia was studied in relation to their ecology and evolution. The ecological environmental factors and biotopic distribution of species were analyzed. The unusually high allozyme variation was found in P. simonsi and P. sp. (2n = 34) inhabiting native forest biotopes. A relatively low allozyme variation in P. brevicauda was assumed to be associated with eurybiotic properties and the ability of this species to adapt to anthropogenic biotopes. Data on chromosome homeology and reconstruction of chromosome rearrangements in six spiny rat species were correlated with allozyme variation. The results suggested that chromosome rearrangements played the major role in evolution of the spiny rat species, and that the reorganization of the P. brevicauda genome was not random. P. simonsi and P. sp. (2n = 34), which live in native forest biotopes and carry an excessive genomik "informational load", were assumed to be highly susceptible to any novel external factors. These species are potentially able to produce new chromosome forms and are most significantly affected by deforestation.     

Plumage based classification of the bowerbird genus Sericulus evaluated using a multi-gene, multi-genome analysis

Past classifications of taxa within the bowerbird genus Sericulus (family: Ptilonorhynchidae) conflict since the discovery of hybrids identified though male plumage characteristics. We use molecular data to help define species within this genus, and by estimating a phylogeny, test for lability in the evolution of male plumage patterns. Because this genus includes the most brightly colored bowerbird species, and is hypothesized to be the basal genus of the avenue building bowerbird clade, the organization of the four taxa within this genus is especially important in understanding how bowerbird plumage coloration evolved. Analyses of two mitochondrial and six nuclear gene regions confirm the basal placement of Sericulus in the avenue building bowerbirds and Sericulus monophyly, and suggests the Australian S. chrysocephalus is the basal Sericulus species. Our analysis additionally supports the existence of three New Guinea Sericulus species, contrary to some previous plumage based classifications, as they are genetically equidistant from each other. Molecular and geographic data of New Guinea are consistent suggesting a series of speciation events starting approximately 3.7-4.3MYA leading to four extant Sericulus species. The absence of resolution within the New Guinea species precludes any statements of trait lability, but does suggest that traits under high selection pressures may not accurately indicate species level distinctions within this genus.     

Phylogeny of the snailfishes (Teleostei: Liparidae) based on molecular and morphological data

Liparidae (snailfishes) is one of the most diverse and abundant fish families in polar and deep-sea habitats. However, the evolution of this family is poorly known because of the rarity of many species and difficulties in scoring morphological characters. We perform phylogenetic analyses of Liparidae using sequences from two mtDNA genes, 16S (585 bp) and cytochrome b (426 bp), and 84 morphological characters from 24 species of Liparidae and 4 species of Cyclopteridae (outgroup). The present study confirms earlier hypotheses that the shallow-water genera, such as Liparis and Crystallichthys, occupy basal positions and that deep-water genera, such as Careproctus, Elassodiscus, Rhinoliparis, Paraliparis, Rhodichthys and Psednos, are increasingly derived. The later two genera form a terminal clade which does not include Paraliparis. The topology shows that the family has undergone a reductive type of evolution, with a gradual loss of characters (e.g. sucking disc/pelvic fins, pseudobranchial filaments, skin spinules). Nectoliparis, which had previously been placed either as the basal most genus or among the most derived genera, are found to occupy the most basal position among the taxa analyzed. This result indicates that the sucking disc has been lost at least twice during the evolution of the Liparidae. The basal position of Nectoliparis is supported by its plesiomorphic otolith morphology, whereas an advanced overgrown otolith ostium, unique among teleosts, is found to be apomorphic for a clade containing the derived genera: Paraliparis, Psednos, Rhinoliparis and Rhodichthys. We also identify the presence of probable nuclear inserts of mitochondrial DNA (Numts) in three species of Careproctus and in Elassodiscus caudatus.     

Phylogeny of the African murid tribe Otomyini (Rodentia), based on morphological and allozyme evidence

Based on a cladistic analysis of 45 morphological (craniodental) and 46 binary allozyme characters, previous systematic treatments of the African murid tribe, Otomyini (laminate-toothed rats), are reviewed. Cladistic analysis of the craniodental data, involving eight outgroup taxa, confirmed the monophyly of the Otomyini, and suggested Pelomys to represent the sister genus of the Otomyini. Craniodental synapomorphies provided strong support for certain basal relationships among Otomyini rodents, reinforcing available palaeontological evidence. However, poor statistical (Bremer decay index) support was obtained for terminal relationships. The data presented revealed a 'mesic clade' of southern and eastern African species, with Otomys sloggetti basal to this group. The arid-adapted, southern Africa-endemic species, Parotomys littledalei , P. brantsii and O. unisulcatus , were all placed basal to the 'mesic clade', but did not form a separate 'arid clade', as suggested by earlier biochemical studies. Two allozyme synapomorphies supported the existence of the 'mesic clade', separate from arid-adapted southern African species. A strict cladistic interpretation of the present data did not support the existence of two genera in the tribe, and the two species of Parotomys (whistling rats) should be transferred to Otomys . At the species level, specific identity of O. lacustris and O. barbouri , distinct from O. anchietae , was supported by several autapomorphies, and O. tropicalis burtoni was shown to be included in O. angoniensis rather than O. tropicalis , extending the range of the former species into West Africa.     

Phylogenetic relationships within the Alcidae (Charadriiformes: Aves) inferred from total molecular evidence

The Alcidae is a unique assemblage of Northern Hemisphere seabirds that forage by "flying" underwater. Despite obvious affinities among the species, their evolutionary relationships are unclear. We analyzed nucleotide sequences of 1,045 base pairs of the mitochondrial cytochrome b gene and allelic profiles for 37 allozyme loci in all 22 extant species. Trees were constructed on independent and combined data sets using maximum parsimony and distance methods that correct for superimposed changes. Alternative methods of analysis produced only minor differences in relationships that were supported strongly by bootstrapping or standard error tests. Combining sequence and allozyme data into a single analysis provided the greatest number of relationships receiving strong support. Addition of published morphological and ecological data did not improve support for any additional relationship. All analyses grouped species into six distinct lineages: (1) the dovekie (Alle alle) and auks, (2) guillemots, (3) brachyramphine murrelets, (4) synthliboramphine murrelets, (5) true auklets, and (6) the rhinoceros auklet (Cerorhinca monocerata) and puffins. The two murres (genus Uria) were sister taxa, and the black guillemot (Cepphus grylle) was basal to the other guillemots. The Asian subspecies of the marbled murrelet (Brachyramphus marmoratus perdix) was the most divergent brachyramphine murrelet, and two distinct lineages occurred within the synthliboramphine murrelets. Cassin's auklet (Ptychoramphus aleuticus) and the rhinoceros auklet were basal to the other auklets and puffins, respectively, and the Atlantic (Fratercula arctica) and horned (Fratercula corniculata) puffins were sister taxa. Several relationships among tribes, among the dovekie and auks, and among the auklets could not be resolved but resembled "star" phylogenies indicative of adaptive radiations at different depths within the trees.      

ALLOZYME DIVERSITY WITHIN AND DIVERGENCE AMONG FOUR SPECIES OF ROBINSONIA (ASTERACEAE: SENECIONEAE), A GENUS ENDEMIC TO THE JUAN FERNANDEZ ISLANDS,CHILE

Enzyme electrophoresis was employed to assess genetic diversity within and divergence among four species of Robinsonia (R. evenia, R. gayana, R. gracilis, R. thurifera), a genus endemic to the Juan Fernandez Islands, Chile. The genus consists of treelike perennial plants, and all species are dioecious. Morphological diversity within the genus is reflected by recognition of two subgenera, with three sections in one subgenus. Total gene diversity is highest in the two species (R. gayana and R. gracilis) that are most common and have the largest population sizes. Robinsonia evenia has only half and the rare R. thurifera only 20% of the diversity detected in the other two species. The diversity measured in R. gayana and R. gracilis is comparable to the values typical of continental species of flowering plants with similar life history attributes. The genetic identities between species range from 0.560 to 0.706, which is similar to or below many values for congeneric species, but much lower than most reports for congeners on oceanic islands. The higher diversity within and divergence among species of Robinsonia compared to many insular endemics may result from several factors. The genus probably arose from selfincompatible plants of the genus Senecio, which means that several to perhaps many colonizers carried considerable allozymic variation to the Islands. Large population sizes and obligate outcrossing are additional factors that would account for higher diversity. Sorting of alleles during radiation and the process of mutation probably combined to produce divergence among the species. Estimated divergence times calculated for the species from allozyme data range from 1.7 to 5.5 million years depending on the assumptions made in the calculations; the age of the island (Masatierra) on which these four species are confined is approximately 4.0 million years. The electrophoretic data suggest that Robinsonia arrived early in the archipelago, and radiated and speciated rapidly after colonization.     

A new genus and species of bothriurid scorpion from the Brandberg Massif, Namibia, with a reanalysis of bothriurid phylogeny and a discussion of the phylogenetic position of Lisposoma Lawrence

Abstract. Brandbergia haringtoni , a new genus and species of bothriurid scorpion, is described from the Brandberg Massif, northwestern Namibia. A cladistic analysis, based on seventy-four morphological characters scored for thirty-one exemplar species representing all genera of Bothriuridae, and one genus from each of the six remaining families of Scorpionoidea, was conducted to test the phylogenetic placement of the new genus and whether it affects the internal relationships of Bothriuridae. The available data demonstrate, under a range of weighting regimes, that the new genus is the most basal bothriurid, and confirm the scheme of relationships among the remaining bothriurid genera that was recovered in a previous analysis: ( Brandbergia ( Lisposoma ( Thestylus ( Phoniocercus ( Tehuankea ( Cercophonius  +  Urophonius ) ( Bothriurus  +  Brachistosternus  + Orobothriurus  +  Centromachetes ( Timogenes  +  Vachonia ))))))). On the basis of this evidence, Lourenço's recent proposal of family Lisposomidae for Lisposoma is rejected and Lisposomidae is synonymized with Bothriuridae. The implications of the phylogeny for understanding the biogeography of Bothriuridae are discussed.     

Phylogenetic relationships of the sea eagles (genus Haliaeetus): reconstructions based on morphology, allozymes and mitochondrial DNA sequences

The relationships of eight extant species of sea eagles (genus Haliaeetus ) and some potentially related Accipitrid genera were investigated. A phylogenetic hypothesis is developed based on morphological characters and allozyme data, which is then contrasted with a reconstruction based on 1071 nucleotides of mitochondrial DNA (cytochrome b and part of one tRNA gene). Phylogenies derived from the three data sets are largely congruent, although several aspects are supported by only one kind of evidence (but not contradicted by the others). Only with regard to the position of south-east Asian H. leucogaster and its closely related sister species H. sanfordi was there conflict between allozyme and mtDNA data. The position of H. pelagicus relative to H. leucoryphus or H. albicilla/leucocephalus could not be resolved with the mtDNA sequence data, suggesting that some speciation events occurred in relatively quick succession during the early Pliocene or late Miocene periods. Available evidence suggests that extant sea eagles originated at tropical latitudes, the northernmost species appearing most derived.