The Experts below are selected from a list of 276 Experts worldwide ranked by ideXlab platform
Adele M Reid - One of the best experts on this subject based on the ideXlab platform.
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are exotic natural enemies an effective way of controlling invasive plants
Trends in Ecology and Evolution, 2007Co-Authors: Matthew B Thomas, Adele M ReidAbstract:Classical biological control (the introduction of exotic natural enemies) is often advocated as a tool for managing invasive Species. Here, we review the effectiveness of biocontrol and explore the factors that determine whether it is an appropriate response to the invasive Species Problem. Although there have been some successes, biocontrol is generally poorly evaluated and, in many cases, its impact is unknown. In particular, there is limited understanding of the nature of the invasive Species Problem and no clear targets against which 'success' can be gauged. In addition, exotic natural enemies could act as invasive Species in their own right. To improve the role of biocontrol in invasive Species management, we need a better ecological understanding of the impacts of both the biocontrol agents and the target invasive Species.
Marc Ereshefsky - One of the best experts on this subject based on the ideXlab platform.
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Mystery of mysteries: Darwin and the Species Problem
Cladistics, 2011Co-Authors: Marc EreshefskyAbstract:Darwin offered an intriguing answer to the Species Problem. He doubted the existence of the Species category as a real category in nature, but he did not doubt the existence of those taxa called “Species”. And despite his scepticism of the Species category, Darwin continued using the word “Species”. Many have said that Darwin did not understand the nature of Species. Yet his answer to the Species Problem is both theoretically sound and practical. On the theoretical side, Darwin’s answer is confirmed by contemporary biology, and it offers a more satisfactory answer to the Species Problem than recent attempts to save the Species category. On the practical side, Darwin’s answer frees us from the search for the correct theoretical definition of “Species”. But at the same time it does not require that we banish the word “Species” from biology as some recent sceptics of the Species category advocate. © The Willi Hennig Society 2010.
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darwin s solution to the Species Problem
Synthese, 2010Co-Authors: Marc EreshefskyAbstract:Biologists and philosophers that debate the existence of the Species category fall into two camps. Some believe that the Species category does not exist and the term ‘Species’ should be eliminated from biology. Others believe that with new biological insights or the application of philosophical ideas, we can be confident that the Species category exists. This paper offers a different approach to the Species Problem. We should be skeptical of the Species category, but not skeptical of the existence of those taxa biologists call ‘Species.’ And despite skepticism over the Species category, there are pragmatic reasons for keeping the word ‘Species.’ This approach to the Species Problem is not new. Darwin employed a similar strategy to the Species Problem 150 years ago.
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Microbiology and the Species Problem
Biology & Philosophy, 2010Co-Authors: Marc EreshefskyAbstract:This paper examines the Species Problem in microbiology and its implications for the Species Problem more generally. Given the different meanings of ‘Species’ in microbiology, the use of ‘Species’ in biology is more multifarious and Problematic than commonly recognized. So much so, that recent work in microbial systematics casts doubt on the existence of a prokaryote Species category in nature. It also casts doubt on the existence of a general Species category for all of life (one that includes both prokaryotes and eukaryotes). Prokaryote biology also undermines recent attempts to save the Species category, such as the suggestion that Species are metapopulation lineages and the idea that ‘Species’ is a family resemblance concept.
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Darwin’s solution to the Species Problem
Synthese, 2009Co-Authors: Marc EreshefskyAbstract:Biologists and philosophers that debate the existence of the Species category fall into two camps. Some believe that the Species category does not exist and the term ‘Species’ should be eliminated from biology. Others believe that with new biological insights or the application of philosophical ideas, we can be confident that the Species category exists. This paper offers a different approach to the Species Problem. We should be skeptical of the Species category, but not skeptical of the existence of those taxa biologists call ‘Species.’ And despite skepticism over the Species category, there are pragmatic reasons for keeping the word ‘Species.’ This approach to the Species Problem is not new. Darwin employed a similar strategy to the Species Problem 150 years ago.
Ralf Meisterfeld - One of the best experts on this subject based on the ideXlab platform.
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The Species Problem in protozoa revisited
European Journal of Protistology, 2003Co-Authors: Martin Schlegel, Ralf MeisterfeldAbstract:The biological Species concept as coined by Ernst Mayr is not applicable to many protists which reproduce by inbreeding or asexually. An extended concept supplementing the biological Species concept was suggested by T. M. Sonneborn after intensive studies on differently reproducing Species of the Paramecium aurelia complex. In his concept based on the hypothesis that inbreeding or asexually reproducing taxa also evolve as discrete units, he suggested that a Species should be recognized as an evolving entity that has undergone a threshold of minimum evolutionary divergence. However, Sonneborns idea was poorly received. We examine different morphological and molecular characters discovered and applied in taxonomy since Sonneborn developed his hypothesis. We conclude that there is now an abundance of objective characters to arrive at sound judgement about the complexity of the genetic differences necessary to delimit Species in Sonneborns sense when the biological Species concept is not applicable. In addition, combined morphological and molecular studies reveal that, although many free-living protists may be globally distributed, geographical patterns and local distribution also occur.
Robert J Toonen - One of the best experts on this subject based on the ideXlab platform.
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clues to unraveling the coral Species Problem distinguishing Species from geographic variation in porites across the pacific with molecular markers and microskeletal traits
PeerJ, 2015Co-Authors: Zac H Forsman, Gerrard M Wellington, Robert J ToonenAbstract:Morphological variation in the geographically widespread coral Porites lobata can make it difficult to distinguish from other massive congeneric Species. This morphological variation could be attributed to geographic variability, phenotypic plasticity, or a combination of such factors. We examined genetic and microscopic morphological variability in P. lobata samples from the Galapagos, Easter Island, Tahiti, Fiji, Rarotonga, and Australia. Panamanian P. evermanni specimens were used as a previously established distinct outgroup against which to test genetic and morphological methods of discrimination. We employed a molecular analysis of variance (AMOVA) based on ribosomal internal transcribed spacer region (ITS) sequence, principal component analysis (PCA) of skeletal landmarks, and Mantel tests to compare genetic and morphological variation. Both genetic and morphometric methods clearly distinguished P. lobata and P. evermanni, while significant genetic and morphological variance was attributed to differences among geographic regions for P. lobata. Mantel tests indicate a correlation between genetic and morphological variation for P. lobata across the Pacific. Here we highlight landmark morphometric measures that correlate well with genetic differences, showing promise for resolving Species of Porites, one of the most ubiquitous yet challenging to identify architects of coral reefs.
Zac H Forsman - One of the best experts on this subject based on the ideXlab platform.
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clues to unraveling the coral Species Problem distinguishing Species from geographic variation in porites across the pacific with molecular markers and microskeletal traits
PeerJ, 2015Co-Authors: Zac H Forsman, Gerrard M Wellington, Robert J ToonenAbstract:Morphological variation in the geographically widespread coral Porites lobata can make it difficult to distinguish from other massive congeneric Species. This morphological variation could be attributed to geographic variability, phenotypic plasticity, or a combination of such factors. We examined genetic and microscopic morphological variability in P. lobata samples from the Galapagos, Easter Island, Tahiti, Fiji, Rarotonga, and Australia. Panamanian P. evermanni specimens were used as a previously established distinct outgroup against which to test genetic and morphological methods of discrimination. We employed a molecular analysis of variance (AMOVA) based on ribosomal internal transcribed spacer region (ITS) sequence, principal component analysis (PCA) of skeletal landmarks, and Mantel tests to compare genetic and morphological variation. Both genetic and morphometric methods clearly distinguished P. lobata and P. evermanni, while significant genetic and morphological variance was attributed to differences among geographic regions for P. lobata. Mantel tests indicate a correlation between genetic and morphological variation for P. lobata across the Pacific. Here we highlight landmark morphometric measures that correlate well with genetic differences, showing promise for resolving Species of Porites, one of the most ubiquitous yet challenging to identify architects of coral reefs.
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is the its region the solution to the Species Problem in corals intragenomic variation and alignment permutations in porites siderastrea and outgroup taxa
2006Co-Authors: T P Huges, Zac H Forsman, Jeanfrancois Flot, Catherine Ozoufcostaz, Makoto Tsuchiya, Robert Van Woesik, Yukimitsu Imahara, Kazunari Ogawa, Cynthia L Hunter, Gerard M WellingtonAbstract:Two widely acknowledged Problems with the use of the ribosomal ITS region as a phylogenetic marker were examined in scleractinian coral: intragenomic variation and alignment ambiguities. Sequences from Caribbean and Eastern Pacific Porites and Siderastrea Species were examined, as well as the nearest available outgroup sequences from GenBank (Tubastrea, Balanophyllia, Scapophyllia and Montastrea). Intragenomic variation was considerably lower than previously reported in corals, and Porites Species were fully resolved. Despite a patchwork of conserved sequence motifs among all taxa, objective alignment between higher taxonomic levels became difficult as gaps and ambiguities increased. To examine the potential for the ITS region to resolve deeper level relationships, fifty alternative alignments were generated by gap-penalty permutation, and examined for consensus. The tree topologies were remarkably congruent, suggesting strong phylogenetic signal at several taxonomic levels. Alternative topologies only rarely occurred at alignment parameter extremes, therefore mid-range parameters were chosen for phylogenetic analysis. The resulting phylogeny was generally consistent with the fossil record, and with previous molecular studies while yielding higher resolution.
