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PARALLEL EVOLUTION OF HAND ANATOMY IN KANGAROOS AND VOMBATIFORM MARSUPIALS: FUNCTIONAL AND EVOLUTIONARY IMPLICATIONS 总被引:1,自引:0,他引:1
Abstract: The anatomy of the mammalian hand is exposed to an intriguing interplay between phylogeny and function, and provides insights on phylogenetic affinities as well as locomotory habits of extinct species. Within the marsupial order Diprotodontia, terrestrial plantigrade quadrupedalism evolved twice, in the mostly extinct vombatiforms and in extant macropodoids. To assess the influence of functional and phylogenetic signal on the manus in these two clades, manual anatomy and digital proportions in specimens of eight extinct and three extant vombatiforms were investigated and compared with extant macropodoids and extant possums. The results reveal extensive parallelisms in the carpal region of vombatiforms and macropodoids, including flattened distal metacarpal facets, reduction of the palmar process of the hamatum, reduction of mid-wrist joint curve, extensive hamatum/scaphoid contact, and absence of a lunatum. These transformations appear to be related to stabilization of the wrist for plantigrade locomotion. Vombatiforms are apomorphic in scaphoid and triquetrum anatomy and their metacarpals are much more gracile than in other Diprotodontia. Manual diversity is greater in vombatiforms than in macropodoids, as probably was locomotor diversity. Digital proportions as well as wrist anatomy divide the extinct vombatiforms into species resembling arboreal diprotodontians, whereas others group with terrestrial quadrupedal kangaroos and wombats. The latter is suggested to be owing to plantigrade locomotion and/or large size. Carpal anatomy and digital proportions suggest that a range of earlier diverging vombatiforms may have been arboreal or scansorial. As such, we propose that the ancestor of extant vombatiforms (koalas and wombats) may have been arboreal, an option that deserves consideration in the reconstruction of vombatiform evolution. 相似文献
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MÁRCIA FERNANDES DE AQUINO SANTOS JOSÉ RICARDO M. MERMUDES VERA MARIA MEDINA DA FONSECA 《Palaeontology》2011,54(4):807-814
Abstract: A specimen of Curculionidae (Curculioninae) is described as Arariperhinus monnei gen. et sp. nov. The specimen is preserved on a laminated limestone sample of the Crato Formation (Santana Group), Lower Cretaceous (Aptian–Albian), and was collected from a quarry near Nova Olinda, Chapada do Araripe, State of Ceará, Brazil. The genus is placed in the subfamily Curculioninae because of its strongly convex body and relatively slender rostrum, but mainly by its rounded eyes and lack of a prosternal sulcus and tibial spurs. The very prominent eyes in lateral view, a cylindrical rostrum and a straight posterior margin of ventrite II are strong indications that this fossil belongs to the tribe Anthonomini. However, the claws, which would resolve the exact placement of this fossil, are poorly preserved. Arariperhinus monnei gen. et sp. nov. is distinguishable by the combination of several characters and the first record of the family Curculionidae in the Santana Group; it is the oldest record of a member of the subfamily Curculioninae. 相似文献
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JEAN V. RUCH HERVÉ LESOT VERA KARCHER-DJURICIC JEAN M. MEYER MARTINE OLIVE 《Differentiation; research in biological diversity》1982,21(1-3):7-12
Numerous studies using amphibians have demonstrated that preodontoblasts emerging from the dental papilla are derived from cranial neural crest cells [4, 12, 46, 64]. However this has not been established for mammals. The history of odontogenesis begins during the early stages of cranial-facial development when the maxillary and mandibular processes develop. Continuous epithelio-mesenchymal interactions condition the histogenesis and morphogenesis of the teeth [24–26, 43, 44, 49, 51,58] as well as the terminal differentiation of odontoblasts and ameloblasts [23, 47, 52, 54, 59, 61, 67].
During recent years a considerable amount of experimental data relating to differentiation of odontoblasts has been published. We summarize these data and attempt to integrate them in deductive hypotheses concerning the control of odontoblast differentiation. 相似文献
During recent years a considerable amount of experimental data relating to differentiation of odontoblasts has been published. We summarize these data and attempt to integrate them in deductive hypotheses concerning the control of odontoblast differentiation. 相似文献
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KAISER D. SCHWARCZ CAIAME L. PATACA ALUANA G. ABREU JOICE M. BARIANI CAMILA M. T. MACRINI VERA N. SOLFERINI 《Botanical journal of the Linnean Society. Linnean Society of London》2010,164(3):326-336
We explore the genetic structure and variability in autochorous Metrodorea nigra (Rutaceae) and anemochorous Astronium graveolens (Anacardiaceae), two species affected by deforestation in the Atlantic Forest of Brazil. The effects of deforestation and the depletion of the habitat within the remaining patches of forest are evaluated by comparing the variability between saplings and adults of each of these two species. The results indicate that the depletion of forest land and the deteriorating condition of the remaining fragments of forest may reduce the level of endogamous breeding in wind‐dispersed species. In autochorous species, the fragmentation of forest land has less notable effects on genetic attributes, but pollen flow could be decreased as a result of the reduced number of insects flying between the forest remnants. © 2010 The Linnean Society of London, Botanical Journal of the Linnean Society, 2010, 164 , 326–336. 相似文献
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Continuous monitoring of phytoplankton dynamics in Lake Balaton (Hungary) using on-line delayed fluorescence excitation spectroscopy 总被引:5,自引:0,他引:5
VERA ISTVÁNOVICS MÁRK HONTI RÁS OSZTOICS HESHAM M. SHAFIK JUDIT PADISÁK YOSSEF YACOBI WERNER ECKERT 《Freshwater Biology》2005,50(12):1950-1970
1. This study introduces delayed fluorescence (DF) excitation spectroscopy as an on‐line tool for in situ monitoring of the composition and biomass of various colour classes of phytoplankton when they are photosynthetically active (cyanobacteria, chlorophytes, chromophytes and cryptophytes). The DF data are validated by comparison with those from conventional methods (weekly microscopic counts and the measurement of chlorophyll concentration). 2. The composition of phytoplankton as assessed by DF agreed reasonably well with the results from microscopic counts, particularly when differences in chlorophyll‐specific DF integrals of the various colour classes were taken into account. 3. Integrals of DF spectra were converted into concentration of chlorophyll a using empirical factors derived from field data. The value of the conversion factor was nearly twice as high when the relative abundance of cyanobacteria was low (<15%) than when it was high. The converted DF‐chl time series agreed well with chlorophyll measurements particularly when blooms were developing. As the DF method is inherently free of the interference caused by pigment degradation products, the discrepancy between the two data sets increased during the collapse of blooms and when sediment resuspension was intense. 4. Fourier spectrum analysis of the time series of DF‐chl indicated that samples must be taken, at a minimum, every 2–3 days to capture the dynamics of phytoplankton. As a consequence, the dynamics of various algal blooms, including their timing, duration and net growth rate, could be estimated with greater confidence than by using conventional methods alone. 5. On‐line DF spectroscopy is an advanced technique for monitoring daily the biomass and composition of the photosynthetically active phytoplankton in aquatic environments, including turbid shallow lakes. At present, the detection limit is around 1 mg DF‐chl a m?3 in terms of total biomass but confidence in estimates of phytoplankton composition declines sharply below about 5 mg chl a m?3. 6. On‐line DF spectroscopy represents a promising approach for monitoring phytoplankton. It will be useful in water management where it can act as an early‐warning system of declines in water quality. In basic ecological research it can supplement manual methods. While default calibration spectra may be acceptable for routine monitoring, we suggest a careful individual calibration of the DF spectrometer for basic research. The statistical methods developed here help to assess the adequacy of various calibration sets. 相似文献
8.
FLORENCIA VERA CANDIOTI BELÉN HAAD DIEGO BALDO FRANCISCO KOLENC CLAUDIO BORTEIRO RONALD ALTIG 《Biological journal of the Linnean Society. Linnean Society of London》2011,104(2):330-345
The oral apparatus of anuran tadpoles is a unique structure composed of soft and keratinized parts surrounding the mouth. Among the many variations, a common oral apparatus involves a dorsal gap in the marginal papillae, keratinized jaw sheaths, and two upper and three lower rows of labial teeth. In Leiuperidae, besides this generalized morphology, four configurations are distinguished by the arrangement of the lower marginal papillae and the number of lower tooth rows. Study of the early oral ontogeny in 12 species representing these five configurations shows variations in the development of the lower marginal papillae and the third lower labial tooth row. Similar configurations may result from similar pathways (e.g. Physalaemus cuvieri group and Pseudopaludicola falcipes) or different pathways (e.g. generalized oral discs of Pleurodema and Physalaemus). Different oral configurations may result from overlapping trajectories ending at different stages (e.g. Physalaemus riograndensis and Ph. biligonigerus) or different trajectories (e.g. Ph. henselii and Ph. gracilis). Further studies are needed to interpret the role that heterochrony has played in evolutionary change within this family. The unsuspected variation occurring in this transient structure highlights its evolutionary potential and might be insightful in studies of anuran phylogenies that are largely based on adult characters. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 104 , 330–345. 相似文献
9.
Sponge proteins are more similar to those of Homo sapiens than to Caenorhabditis elegans 总被引:2,自引:0,他引:2
VERA GAMULIN ISABEL M. MULLER WERNER E.G. MULLER 《Biological journal of the Linnean Society. Linnean Society of London》2000,71(4):821-828
We compared 42 phylogenetically conserved proteins from four marine sponges [Porifera] with almost the complete set of Caenorhabditis elegans proteins and all known proteins from humans. The majority of the sponge proteins arc significantly more similar to human than to C. elegans orthologucs/homologues. This finding reflects the accelerated evolutionary rate in the C. elegans lineage, since sponges split off first from the common ancestor of all multicellular animals. Furthermore, three sponge/human proteins were not found in C. elegans: (2–5)A synthetase, DNA repair helicase and lens βγ-crystallin. Sponges arc the source of the most ancient proteins already present in the common ancestor of all multicellular organisms. Some of these proteins were lost later during the evolution of individual animal lineages. These 'found/lost' proteins may serve as molecular markers for an improved systematics of Metazoa. In addition, phylogenetically conserved sponge proteins can be very helpful for the evaluation of differences in evolutionary rates in different animal lineages. We therefore propose sponges as the reference animals in molecular evolutionary studies of Metazoa. 相似文献
10.
KARINA LUCAS SILVA-BRANDÃO VERA NISAKA SOLFERINI 《Biological journal of the Linnean Society. Linnean Society of London》2007,90(2):247-261
Molecular phylogenetic analyses were conducted to determine relationships and to investigate character evolution for the Troidini/Aristolochia interaction, in an attempt to answer the following questions: (1) what is the present pattern of use of Aristolochia by these butterflies; (2) is the pattern we see today related to the phylogeny of plants or to their chemical composition; (3) can the geographical distribution of Aristolochia explain the host plant use observed today; and (4) how did the interaction between Troidini and Aristolochia evolve? Analyses of character optimization suggest that the current pattern of host plant use of these butterflies does not seem to be constrained by the phylogeny of their food plants, neither by the secondary chemicals in these plants nor by their geographical similarity. The current host plant use in these butterflies seems to be simply opportunistic, with species with a wider geographical range using more species of host plants than those with a more restricted distribution. © 2007 The Linnean Society of London, Biological Journal of the Linnean Society, 2007, 90 , 247–261. 相似文献