| 1. |
- Douglas, Desiree, et al.
(författare)
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A mitogenomic study on the phylogenetic position of snakes
- 2006
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Ingår i: Zoologica Scripta. - : Wiley. - 0300-3256 .- 1463-6409. ; 35:6, s. 545-558
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Tidskriftsartikel (refereegranskat)abstract
- Phylogenetic relationships of squamates (lizards, amphisbaenians and snakes) have received considerable attention, although no consensus has been reached concerning some basal divergences. This paper focuses on the Serpentes (snakes), whose phylogenetic position within the Squamata remains uncertain despite a number of morphological and molecular studies. Some mitogenomic studies have suggested a sister-group relationship between snakes and varanid lizards, while other studies have identified snakes and lizards as sister groups. However, recent studies using nuclear data have presented a different scenario, with snakes being more closely related to anguimorph and iguanian lizards. In this mitogenomic study we have examined the above hypotheses with the inclusion of amphisbaenians, one gekkotan and one acrodont lizard, taxa not represented in previous mitogenomic studies. To this end we have also extended the representation of snakes by sequencing five additional snake genomes: two scolecophidians (Ramphotyphlops australis and Typhlops mirus) two henophidians (Eunectes notaeus and Boa constrictor) and one caenophidian (Elaphe guttata). The phylogenetic analysis recovered snakes and amphisbaenians as sister groups, thereby differing from previous hypotheses. In addition to a discussion on previous morphological and molecular studies in light of the results presented here, the current study also provides some details regarding features of the new snake mitochondrial genomes described.
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| 2. |
- Elofsson, Rolf
(författare)
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Rhabdom adaptation and its phylogenetic significance
- 1976
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Ingår i: Zoologica Scripta. - : Wiley. - 0300-3256 .- 1463-6409. ; 5, s. 97-101
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Tidskriftsartikel (refereegranskat)abstract
- Rhabdom adaptation and its phylogenetic significance. Zool. Scr. 5 (3–4): 97–101, 1976. — The rhabdoms of arthropod compound eyes are structurally differentiated into open, fused layered, and fused continuous. All are capable of perceiving polarized light. The fused layered, and under certain conditions the fused continuous, perform particularly well. — The fused layered rhabdoms occur in malacostracan crustaceans and in various insect groups. This, together with, among other things, the presence of open rhabdoms in insects and crustaceans, indicates convergent development of organs and parts of organs. — Elaborate visual organs of more than one kind occur in crustaceans, as is exemplified by the compound and nauplius eyes. This shows that more than one construction on the organ level is possible in a restricted taxo-nomical unit for the. perception of light. The different rhabdom types performing well in receiving polarized light also show parallel evolution on a level below the organ. — The result of adaptation analyses indicates the need for a restricted use of the concept of homology basic to morphological investigations and a base for phylogenetic speculations. It also envisages a fruitful approach to a peep into the workshop of evolution. — It is concluded that a fully formed compound eye in arthropod ancestors is hardly conceivable. A realistic alternative is an inherent capacity of forming a compound eye. Thus the ancestral compound eye could have ranged from nothing to a partly-developed stage. The recent eyes need not originate from one source.
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| 3. |
- Elofsson, Rolf, et al.
(författare)
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The Eltringham organ and a new thoracic gland: Ultrastructure and presumed pheromone function (Insecta. Myrmeleontidae)
- 1974
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Ingår i: Zoologica Scripta. - : Wiley. - 0300-3256 .- 1463-6409. ; 3, s. 31-40
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Tidskriftsartikel (refereegranskat)abstract
- Eltringham's organ is a club-like projection from the posterior margin of hind-wings of some myrmeleontid insects. It bears laterally directed setae, each having a specialized epidermal cell beneath, which gives off secretion into a sub-setal lumen. The lumen continues into the wall of the moat-like socket of the setae. Eltringham's organ fits into an excavation of the lateral body wall connected with the opening of a thoracic gland. The thoracic gland in these animals has not previously been described. It consists of a hollow tube, feebly developed in females. The tube wall houses two cell types: gland cells and cuticular cells. The latter form the cuticle of the general duct lumen and a specialized duct leading from each gland cell. The gland cells have a microvilli-filled cavity which collects the secretion. The thoracic gland produces a pheromone secretion whose distribution is aided by Eltringham's organ where present.
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| 4. |
- Kjaerandsen, Jostein
(författare)
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A revision of the Afrotropical genus Dhatrichia Mosely, 1948 (Trichoptera, Hydroptilidae).
- 2004
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Ingår i: Zoologica Scripta. - : Wiley. - 0300-3256 .- 1463-6409. ; 33:2, s. 131-185
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Tidskriftsartikel (refereegranskat)abstract
- Five previously described species of Dhatrichia Mosely, 1948 are recognized: D. inasa Mosely, 1948 from Yemen; D. bipunctata Statzner, 1977 from Zaire; D. lerabae (Gibon, Guenda & Coulibaly, 1994) comb. n. from Burkina Faso and Ghana; and D. cinyra Wells & Andersen, 1995 and D. divergenta Wells & Andersen, 1995 from Tanzania. A sixth species D. feredougoubae Gibon, 1987 from the Ivory Coast and Ghana is transferred to Microptila Ris, 1897 comb. n. In addition, nine new species are described and illustrated as males: D. ankasaensis sp. n., D. botiensis sp. n., D. hunukani sp. n., D. minuta sp. n., D. paraminuta sp. n. and D. wliensis sp. n. from Ghana, D. anderseni sp. n. from Tanzania, and D. madagascarensis sp. n. and D. giboni sp. n. from Madagascar. Females are associated, described and illustrated for all species, except D. inasa and D. giboni. The larvae and pupae of D. ankasaensis, D. hunukani, D. lerabae, D. minuta and D. wliensis are described and illustrated as the first known immatures of the genus. Keys to known larvae, pupae, males and females are provided. A phylogenetic analysis of the genus revealed four species groups. The most plesiomorphous taxa are West African, followed by East African and Malagasian taxa. A sister group relationship between the Eburneo–Ghanean and the Sudanian biogeographical regions is encountered twice. Among several possible sister taxa, the sister group turned out to be Kumanskiella Harris & Flint, 1992 and Microptila Ris, 1897 in part, combined. Implications for generic classification and biogeography are outlined. A morphometric principal component analysis revealed good separation of the sexes by the number and shape of antennal segments, and by eye size. Other measures are strongly dependent on overall size, and show best separation of females between species and species groups. A functional fit between male inferior appendages and secondary sexual characters in female sternite VIII is demonstrated for all species with associated females.
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| 5. |
- Kullberg, Morgan, et al.
(författare)
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Phylogenetic analysis of 1.5 Mbp and platypus EST data refute the Marsupionta hypothesis and unequivocally support Monotremata as sister group to Marsupialia/Placentalia
- 2008
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Ingår i: Zoologica Scripta. - : Wiley. - 0300-3256 .- 1463-6409. ; 37:2, s. 115-127
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Tidskriftsartikel (refereegranskat)abstract
- The extant mammalian groups Monotremata, Marsupialia and Placentalia are, according to the ‘Theria’ hypothesis, traditionally classified into two subclasses. The subclass Prototheria includes the monotremes and subclass Theria marsupials and placental mammals. Based on some morphological and molecular data, an alternative proposition, the Marsupionta hypothesis, favours a sister group relationship between monotremes and marsupials to the exclusion of placental mammals. Phylogenetic analyses of single genes and even multiple gene alignments have not yet been able to conclusively resolve this basal mammalian divergence. We have examined this problem using one data set composed of expressed sequence tags (EST) and another containing 1 510 509 nucleotide (nt) sites from 1358 inferred cDNA genomic sequences. All analyses of the concatenated sequences unambiguously supported the Theria hypothesis. The Marsupionta hypothesis was rejected with high statistical confidence from both data sets. In spite of the strong support for Theria, a non-negligible number of single genes supported either of the two alternative hypotheses. The divergence between monotremes and therian mammals was estimated to have taken place 168–178 Mya, a dating compatible with the fossil record. Considering the long common evolutionary branch of therians, it is surprising that sequence data from many thousand amino acid sites were needed to conclusively resolve their relationship to monotremes. This finding draws attention to other mammalian divergences that have been taken as unequivocally settled based on much smaller alignments. EST data provide a comprehensive random sample of protein coding sequences and an economic way to produce large amounts of data for phylogenetic analysis of species for which genomic sequences are not yet available.
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| 6. |
- Lindqvist, Charlotte, et al.
(författare)
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The Laptev Sea walrus Odobenus rosmarus laptevi: an enigma revisited
- 2009
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Ingår i: Zoologica Scripta. - : Wiley. - 0300-3256 .- 1463-6409. ; 38:2, s. 113-127
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Tidskriftsartikel (refereegranskat)abstract
- The walrus (Odobenus rosmarus) is in some current systematic schemes divided into three subspecies: O. r. rosmarus in the North Atlantic, O. r. divergens in the North Pacific and O. r. laptevi in the Laptev Sea. These three subspecies have been described as differing in body size, but the taxonomic status of O. r. laptevi is disputed. The current study applies molecular and morphometric methods to assess the taxonomic status of O. r. laptevi and to analyse the systematic and phylogeographic relationships between the three purported walrus subspecies. Tusk length and tusk circumference were measured from the few skulls available of O. r. laptevi, and the obtained values were within the ranges reported for Pacific walruses. Thus, morphologically, subspecies status for O. r. laptevi is not supported according to the Amadon Mayr '75% rule'. Phylogenetic analyses and haplotype networks based on mitochondrial nucleotide sequence data of NADH dehydrogenase 1, 16S rRNA, cytochrome oxidase I and the D-loop of the control region of the historic O. r. laptevi bone material and contemporary O. r. rosmarus and O. r. divergens showed that the Laptev Sea walrus groups with individuals from the North Pacific. Thus, the mitochondrial sequence data do not support the recognition of three walrus subspecies as reciprocally monophyletic evolutionary units with independent evolutionary histories. Only O. r. rosmarus and O. r. divergens meet this criterion with the present sampling. Accordingly, we recommend that Odobenus r. laptevi be abandoned and the Laptev walrus instead be recognized as the westernmost population of the Pacific walrus, Odobenus r. divergens. However, further research is recommended to assess whether the Laptev walrus could be considered as a significant unit in terms of conservation and management, since it is unique in several ecological parameters.
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| 7. |
- Nilsson, Maria
(författare)
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Phylogenetic relationships of the Banded Hare wallaby (Lagostrophus fasciatus) and a map of the kangaroo mitochondrial control region
- 2006
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Ingår i: Zoologica Scripta. - : Wiley. - 0300-3256 .- 1463-6409. ; 35:4, s. 387-393
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Tidskriftsartikel (refereegranskat)abstract
- The complete mitochondrial genome of the endangered Banded Hare wallaby (Lagostrophus fasciatus) was sequenced and used for phylogenetic analysis. The data set consisted of 10 377 nucleotides (3459 amino acids) from three kangaroo species. The phylogenetic analyses strongly supported the hypothesis that the Banded Hare wallaby is the sister-group of the wallaroo (subfamily Macropodidae). In addition to the phylogenetic reconstruction, the mt control region, or (D)-loop, from Australian marsupials has been mapped for the first time. The results show that the organization of the kangaroo control region is similar to that of placental mammals. The presence of a duplicated CSB-1 block found in all three kangaroo species is an uncommon feature of mammalian mt DNA. The CSB domain was found to be the most variable region in the control region, followed by a less variable ETAS domain.
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| 8. |
- Rindal, E., et al.
(författare)
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Molecular phylogeny of the fungus gnat tribe Exechiini (Mycetophilidae. Diptera).
- 2007
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Ingår i: Zoologica Scripta. - : Wiley. - 0300-3256 .- 1463-6409. ; 36:4, s. 327-335
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Tidskriftsartikel (refereegranskat)abstract
- The phylogenetic relationships within the fungus gnat tribe Exechiini have been left unattended for many years. Recent studies have not shed much light on the intergeneric relationship within the tribe. Here the first attempt to resolve the phylogeny of the tribe Exechiini using molecular markers is presented. The nuclear 18S and the mitochondrial 16S, and cytochrome oxidase subunit I (COI) genes were successfully sequenced for 20 species representing 15 Exechiini genera and five outgroup genera. Bayesian, maximum parsimony and maximum likelihood analyses revealed basically congruent tree topologies and the monophyly of Exechiini, including the genus Cordyla, is confirmed. The molecular data corroborate previous morphological studies in several aspects. Cordyla is found in a basal clade together with Brachypeza, Pseudorymosia and Stigmatomeria. The splitting of the genera Allodiopsis s.l. and Brevicornu s.l. as well as the sistergroup relationship of Exechia and Exechiopsis is also supported. The limited phylogenetic information provided by morphological characters is mirrored in the limited resolution of the molecular markers used in this study. Short internal and long-terminal branches obtained may indicate a rapid radiation of the Exechiini genera during a short evolutionary period.
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| 9. |
- Ohlson, Jan I, et al.
(författare)
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Tyrant flycatchers coming out in the open: phylogeny and ecological radiation of Tyrannidae (Aves, Passeriformes)
- 2008
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Ingår i: Zoologica Scripta. - : Wiley. - 0300-3256 .- 1463-6409. ; 37:3, s. 315-335
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Tidskriftsartikel (refereegranskat)abstract
- Tyrant flycatchers constitute a substantial component of the land bird fauna in all South American habitats. Past interpretations of the morphological and ecological evolution in the group have been hampered by the lack of a well-resolved hypothesis of their phylogenetic interrelationships. Here, we present a well-resolved phylogeny based on DNA sequences from three nuclear introns for 128 taxa. Our results confirm much of the overall picture of Tyrannidae relationships, and also identify several novel relationships. The genera Onychorhynchus, Myiobius and Terenotriccus are placed outside Tyrannidae and may be more closely related to Tityridae. Tyrannidae consists of two main lineages. An expanded pipromorphine clade includes flatbills, tody-tyrants and antpipits, and also Phylloscartes and Pogonotriccus. The spadebills, Neopipo and Tachuris are their closest relatives. The remainder of the tyrant flycatchers forms a well-supported clade, subdivided in two large subclades, which differ consistently in foraging behaviour, the perch-gleaning elaeniines and the sallying myiarchines, tyrannines and fluvicolines. A third clade is formed by the genera Myiotriccus, Pyrrhomyias, Hirundinea and three species currently placed in Myiophobus. Ancestral habitat reconstruction and divergence date estimation suggest that early divergence events in Tyrannida took place in a humid forest environment during the Oligocene. Large-scale diversification in open habitats is confined to the clade consisting of the elaeniines, myiarchines, tyrannines and fluvicolines. This radiation correlates in time to the expansion of semi-open and open habitats from the mid-Miocene (c. 15 Mya) onwards. The pipromorphine, elaeniine and myiarchine–tyrannine–fluvicoline clades each employ distinct foraging strategies (upward striking, perch-gleaning and sallying, respectively), but the degree of diversity in morphology and microhabitat exploitation is markedly different between these clades. While the pipromorphines and elaeniines each are remarkably homogenous in morphology and exploit a restricted range of microhabitats, the myiarchine–tyrannine–fluvicoline clade is more diverse in these respects. This greater ecological diversity, especially as manifested in their success in colonizing a wider spectrum of open habitats, appears to be connected to a greater adaptive flexibility of the search-and-sally foraging behaviour.
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| 10. |
- Bertrand, Yann, et al.
(författare)
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Phylogenetic hypotheses, taxonomic sameness and the reference of taxon names
- 2008
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Ingår i: Zoologica Scripta. - : Wiley. - 0300-3256 .- 1463-6409. ; 37:3, s. 337-347
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Tidskriftsartikel (refereegranskat)abstract
- When scientists use a taxon name like Mammalia, it is important that they talk about the same thing. But, what does it mean to be the same thing in different phylogenetic hypotheses? And, how is taxonomic reference maintained across hypotheses? Here, we discuss the differences between real and hypothetical clades, and how such a distinction relates to the sameness problem. Since hypotheses influence how we perceive things and pursue science, we find it important to have a functioning nomenclatural system for clades as perceived in phylogenetic hypotheses. As a solution to the sameness problem for such clades, we argue that a taxon name does not primarily refer to a single clade that somehow mirror the reality of branches in the tree of life. Instead we suggest that a taxon name refers to a set, or natural kind, of counterfactual and reconstructed clades.
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