Search Results - (Author, Cooperation:H. Lessios)
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1Latest Papers from Table of Contents or Articles in PressL. A. Rocha ; A. Aleixo ; G. Allen ; F. Almeda ; C. C. Baldwin ; M. V. Barclay ; J. M. Bates ; A. M. Bauer ; F. Benzoni ; C. M. Berns ; M. L. Berumen ; D. C. Blackburn ; S. Blum ; F. Bolanos ; R. C. Bowie ; R. Britz ; R. M. Brown ; C. D. Cadena ; K. Carpenter ; L. M. Ceriaco ; P. Chakrabarty ; G. Chaves ; J. H. Choat ; K. D. Clements ; B. B. Collette ; A. Collins ; J. Coyne ; J. Cracraft ; T. Daniel ; M. R. de Carvalho ; K. de Queiroz ; F. Di Dario ; R. Drewes ; J. P. Dumbacher ; A. Engilis, Jr. ; M. V. Erdmann ; W. Eschmeyer ; C. R. Feldman ; B. L. Fisher ; J. Fjeldsa ; P. W. Fritsch ; J. Fuchs ; A. Getahun ; A. Gill ; M. Gomon ; T. Gosliner ; G. R. Graves ; C. E. Griswold ; R. Guralnick ; K. Hartel ; K. M. Helgen ; H. Ho ; D. T. Iskandar ; T. Iwamoto ; Z. Jaafar ; H. F. James ; D. Johnson ; D. Kavanaugh ; N. Knowlton ; E. Lacey ; H. K. Larson ; P. Last ; J. M. Leis ; H. Lessios ; J. Liebherr ; M. Lowman ; D. L. Mahler ; V. Mamonekene ; K. Matsuura ; G. C. Mayer ; H. Mays, Jr. ; J. McCosker ; R. W. McDiarmid ; J. McGuire ; M. J. Miller ; R. Mooi ; R. D. Mooi ; C. Moritz ; P. Myers ; M. W. Nachman ; R. A. Nussbaum ; D. O. Foighil ; L. R. Parenti ; J. F. Parham ; E. Paul ; G. Paulay ; J. Perez-Eman ; A. Perez-Matus ; S. Poe ; J. Pogonoski ; D. L. Rabosky ; J. E. Randall ; J. D. Reimer ; D. R. Robertson ; M. O. Rodel ; M. T. Rodrigues ; P. Roopnarine ; L. Ruber ; M. J. Ryan ; F. Sheldon ; G. Shinohara ; A. Short ; W. B. Simison ; W. F. Smith-Vaniz ; V. G. Springer ; M. Stiassny ; J. G. Tello ; C. W. Thompson ; T. Trnski ; P. Tucker ; T. Valqui ; M. Vecchione ; E. Verheyen ; P. C. Wainwright ; T. A. Wheeler ; W. T. White ; K. Will ; J. T. Williams ; G. Williams ; E. O. Wilson ; K. Winker ; R. Winterbottom ; C. C. Witt
American Association for the Advancement of Science (AAAS)
Published 2014Staff ViewPublication Date: 2014-05-24Publisher: American Association for the Advancement of Science (AAAS)Print ISSN: 0036-8075Electronic ISSN: 1095-9203Topics: BiologyChemistry and PharmacologyComputer ScienceMedicineNatural Sciences in GeneralPhysicsKeywords: Animals ; Biology/*methods ; Classification/*methods ; *Endangered Species ; *Extinction, BiologicalPublished by: -
2Articles: DFG German National LicensesStaff View
ISSN: 1476-4687Source: Nature Archives 1869 - 2009Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsNotes: [Auszug] It is important to resolve this issue for two reasons: first, the assumption of a linear relationship between time since separation and degree of molecular divergence has been used extensively to assign dates to the splitting of two lineages on the basis of biochemical evidence11'15 and second, the ...Type of Medium: Electronic ResourceURL: -
3Articles: DFG German National LicensesStaff View
ISSN: 1476-4687Source: Nature Archives 1869 - 2009Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsNotes: [Auszug] Sir The case of Guillermo Gonzalez being denied tenure at Iowa State University should figure prominently in court next time there is an attempt to introduce intelligent design into the school science curriculum. According to your News story (Nature 447, ...Type of Medium: Electronic ResourceURL: -
4Articles: DFG German National LicensesStaff View
ISSN: 1432-0975Source: Springer Online Journal Archives 1860-2000Topics: BiologyGeosciencesNotes: Abstract The existing literature reports that only one species of Indo-Pacific echinoid (Echinometra oblonga), occurs in the eastern Pacific. In this study we confirm the presence of this species at Islas Revillagigedo and also report the presence of two species ofEchinothrix (a genus hitherto unknown outside the Indo-Pacific) at Isla del Coco and at Clipperton Island. We also present evidence from isozymes and from mitochondrial DNA sequences indicating that at least one individual ofDiadema at Clipperton may belong to a maternal lineage characteristic of the west Pacific speciesD. savignyi. These data are consistent with the hypothesis that the observed populations of Indo-Pacific echinoid species are recent arrivals to the eastern Pacific, as opposed to the view that they are relicts of Tethyan pan-tropical distributions.Echinothrix diadema, in particular, may have arrived at Isla del Coco during the 1982-1983 El Nifio. In addition to Indo-Pacific species, Clipperton, Isla del Coco and the Revillagigedos contain a complement of eastern Pacific echinoids. The echinoid faunas of these islands should, therefore, be regarded as mixtures of two biogeographic provinces. Though none of the Indo-Pacific species are known to have reached the coast of the American mainland, their presence at the offshore islands of the eastern Pacific suggests that, for some echinoids, the East Pacific Barrier is not as formidable an obstacle to migration as was previously thought.Type of Medium: Electronic ResourceURL: -
5Articles: DFG German National LicensesLessios, H. A. ; Cubit, J. D. ; Robertson, D. R. ; Shulman, M. J. ; Parker, M. R. ; Garrity, S. D. ; Levings, S. C.
Springer
Published 1984Staff ViewISSN: 1432-0975Source: Springer Online Journal Archives 1860-2000Topics: BiologyGeosciencesNotes: Abstract The ecologically important sea urchin Diadema antillarum suffered mass mortalities in 1983, first noted in Panama and then reported from the rest of the Caribbean. We documented the effects of this mortality at two localities on the Atlantic coast of Panama, Punta Galeta and the San Blas Archipelago. At Punta Galeta, affected by the mortality in January 1983, the numbers of D. antillarum changed from an estimated 14,000 per ha in June 1982 to 0.5 per ha in May 1983; by February 1984 they had increased to 38 per ha. In the San Blas, where mass mortality started in April 1983, the number of D. antillarum in permanent quadrats on 8 reefs was reduced by an average of 94.2%. The average reduction in population density measured in transects on nine reefs was 98.9%. Data taken in permanent quadrats on four reefs in 1978, 1979 and 1980 indicate that population fluctuations of D. antillarum are normally much smaller, justifying the labeling of the 1983 event as “mass mortality”. Size structure of the San Blas populations was also affected; mean test diameter of D. antillarum on four reefs was reduced from 48.6 mm to 25.0 mm. Other echinoids (Echinometra viridis, E. lucunter, Lytechinus variegatus, L. williamsi, Eucidaris tribuloides, Tripneustes ventricosus, Clypeaster rosaceus and Echinoneus cyclostomus) suffered no ill effects at either Galeta or the San Blas; their population densities remained stable or increased. Density determinations of Diadema mexicanum at the island of Taboguilla on the Pacific side of Panama indicate that Diadema mass mortality did not extend to the eastern Pacific. Sea surface temperatures, tidal levels, rainfall and salinity showed no abnormal fluctuations during the time of D. antillarum mass mortality at Galeta, suggesting that mortality was not due to physical stress. The wide geographical spread and species-specificity of the mortality suggest a water-borne pathogen as the most likely causative agent. Recovery of D. antillarum populations is likely to be slow because there are few, if any, unaffected populations in the Caribbean to contribute larvae for the recolonization of depleted areas. The absence of D. antillarum will probably be reflected by changes in the algal, coral and echinoid communities, and by altered patterns of bioerosion.Type of Medium: Electronic ResourceURL: -
6Articles: DFG German National LicensesStaff View
ISSN: 1432-0975Source: Springer Online Journal Archives 1860-2000Topics: BiologyGeosciencesNotes: Abstract The existing literature reports that only one species of Indo-Pacific echinoid (Echinometra oblonga), occurs in the eastern Pacific. In this study we confirm the presence of this species at Islas Revillagigedo and also report the presence of two species of Echinothrix (a genus hitherto unknown outside the Indo-Pacific) at Isla del Coco and at Clipperton Island. We also present evidence from isozymes and from mitochondrial DNA sequences indicating that at least one individual of Diadema at Clipperton may belong to a maternal lineage characteristic of the west Pacific species D. savignyi. These data are consistent with the hypothesis that the observed populations of Indo-Pacific echinoid species are recent arrivals to the eastern Pacific, as opposed to the view that they are relicts of Tethyan pan-tropical distributions. Echinothrix diadema, in particular, may have arrived at Isla del Coco during the 1982–1983 El Nin o. In addition to Indo-Pacific species, Clipperton, Isla del Coco and the Revillagigedos contain a complement of eastern Pacific echinoids. The echinoid faunas of these islands should, therefore, be regarded as mixtures of two biogeographic provinces. Though none of the Indo-Pacific species are known to have reached the coast of the American mainland, their presence at the offshore islands of the eastern Pacific suggests that, for some echinoids, the East Pacific Barrier is not as formidable an obstacle to migration as was previously thought.Type of Medium: Electronic ResourceURL: -
7Articles: DFG German National LicensesStaff View
ISSN: 1432-1793Source: Springer Online Journal Archives 1860-2000Topics: BiologyNotes: Abstract We present the first case of hybridization between echinoid species evaluated through genetic markers and morphology. We examined the three tropical Indo-Pacific species of the genus Diadema: D. paucispinum A. Agassiz, D. savignyi (Audouin) Michelin and D. setosum (Leske). Specimens morphologically intermediate between two of these species, D. savignyi and D. setosumhave previously been noted. Fertile hybrids have also been produced in the laboratory. To determine extent of hybridization, we first assayed the allozyme products of 22 loci in individuals which, on the basis of morphology and collection locality, could be unambiguously assigned to one of the three species. We found four loci that were either diagnostic or semi-diagnostic between D. setosum and the other two species, and one locus semi-diagnostic between D. savignyi and D. paucispinum.We then assayed individuals of intermediate morphology to find out whether they had hybrid genotypes. In the Ryukyu Islands, where D. setosum and D. savignyi coexist, we found one specimen which on the basis of all four diagnostic loci was an F1 hybrid, and several individuals that could be either F2 (or later-generation) hybrids or progeny of backcrosses.We also found one individual that on both genetic and morphological grounds appeared to belong to D. paucispinum (even though this spcies has only been reported from Hawaii and Kiribati) and three other individuals that carried alleles characteristic of D. paucispinum. Thus, previous reports of hybridization between D. setosum and D. savignyi were correct; it is also possible that larvae of D. paucispinum occasionally arrive at localities outside Hawaii, reach sexual maturity, and hybridize with the other two species. Counts of pure and hybrid morphotypes in other populations across the western tropical Pacific revealed a low but widespread incidence of apparent F1 hybrids and backcrosses of D.savignyi and D. setosum. However, the existence of diagnostic or semi-diagnostic loci, low interspecific gene-flow estimates based on F st statistics, and the lack of Hardy-Weinberg or linkage disequilibria among individuals of pure morphology all suggest that gene introgression between the three species is limited.Type of Medium: Electronic ResourceURL: -
8Articles: DFG German National LicensesStaff View
ISSN: 1432-1793Source: Springer Online Journal Archives 1860-2000Topics: BiologyNotes: Abstract Electrophoretic data from marine organisms are routinely tested for conformity to expectations of the Hardy-Weinberg rule, but the statistical procedures used and the interpretation of their results are often flawed. This paper summarizes literature on statistical testing for Hardy-Weinberg equilibrium and suggests and analytical strategy based on carrying out computationally simple goodness-of-fit ϰ2 tests (with pooling and correction factors for continuity if necessary) when appropriate, and resorting to computationally tedious, exact tests when necessary. It recommends adjustments of significance levels to avoid the large Type-I error that may result from multiple tests for Hardy-Weinberg equilibrium, one for each locus and each population. It points out the obvious but common error of interpreting non-significant tests as evidence of conformity to Hardy-Weinberg expectations, and makes suggestions as to how tests that produce significance can be used to reach conclusions of biological relevance.Type of Medium: Electronic ResourceURL: -
9Articles: DFG German National LicensesStaff View
ISSN: 1432-1793Source: Springer Online Journal Archives 1860-2000Topics: BiologyNotes: Abstract In 1983, Diadema antillarum suffered mass mortality throughout the Caribbean Sea and the western Atlantic Ocean. I followed the dynamics of populations at the San Blas Islands, Panamá from April 1983 to November 1987. Density measurements indicate that populations of D. antillarum have not recovered from the die-offs that killed nearly 97% of the individuals. There was recruitment to the 1 to 1.5 cm class immediately after the mass mortality, but there has been little additional influx of juveniles since then. The low number of observable juveniles could not be attributed to elevated rates of predation on very small individuals. Rates of recruitment did not differ between reefs with artificially increased densities of D. antillarum and reefs kept free of sea urchins; thus, the lack of recruitment did not arise from absence of adults that could provide settlement cues to the larvae or protection to newly settled juveniles. Other species of sea urchins did not show a clear pattern of increase after the demise of D. antillarum. Therefore, interspecific competition directed towards D. antillarum juveniles did not increase after the mass mortality. Two reefs where Echinometra viridis, Eucidaris tribuloides and Lytechinus williamsi, were removed showed no significant differences in recruitment of D. antillarum relative to two reefs where these species were allowed to remain at their natural densities. Resident D. antillarum after the mass mortality produced gametes with the same per capita intensity and lunar synchrony as before the mass mortality. However, it is possible that the probability of fertilization of their gametes decreased because of low population density. The most likely explanation for lack of recruitment is that the reduced numbers of reproducing adults at Panamá and upstream locations resulted in levels of larval supply that were inadequate to sustain recruitment on Panamanian reefs.Type of Medium: Electronic ResourceURL: