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- Härlin, Mikael, et al.
(författare)
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Taxonomy and philosophy of names
- 1998
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Ingår i: Biology & Philosophy. - 0169-3867 .- 1572-8404. ; 13:2, s. 233-244
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Tidskriftsartikel (refereegranskat)abstract
- Although naming biological clades is a major activity in taxonomy, little attention has been paid to what these names actually refer to. In philosophy, definite descriptions have long been considered equivalent to the meaning of names and biological taxonomy is a scientific application of these ideas. One problem with definite descriptions as the meanings of names is that the name will refer to whatever fits the description rather than the intended individual (clade). Recent proposals for explicit phylogenetic definitions of clade names suffer from similar problems and we argue that clade names cannot be defined since they lack intension. Furthermore we stress the importance of "tree-thinking" for phylogenetic reference to work properly.
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| 2. |
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| 3. |
- Härlin, Mikael
(författare)
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Phylogenetic approaches to nomenclature : a comparison based on a nemertean case study.
- 1999
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Ingår i: Proceedings of the Royal Society of London. Biological Sciences. - : The Royal Society. - 0962-8452 .- 1471-2954. ; 266:1434, s. 2201-2207
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Tidskriftsartikel (refereegranskat)abstract
- Phylogenetic approaches to biological nomenclature are becoming increasingly common. Here I compare the behaviour of two such approaches, the phylogenetic system of definition and the phylogenetic system of reference, when there is a shift in the preference of phylogenetic hypotheses. The comparison is based on a case study from nemertean systematics and is the first to compare two different phylogenetic approaches throughout three stages of change, including two stages of phylogenetic nomenclature. It is concluded that a phylogenetic system of reference in combination with uninomials is superior in conveying phylogenetic information.
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| 4. |
- Härlin, Mikael, et al.
(författare)
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Cladistic analysis of the eureptantic nemerteans (Nemertea : Hoplonemertea)
- 1995
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Ingår i: Invertebrate taxonomy. - 0818-0164 .- 1445-4572. ; 9:6, s. 1211-1229
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Tidskriftsartikel (refereegranskat)abstract
- A phylogeny for the 34 species we consider well enough described in the suborder Eureptantia (phylum Nemertea) is inferred by cladistic analysis based on 38 morphological characters. The phylogenetic reconstruction indicates that many previously recognised genera and families are paraphyletic. These findings are discussed and compared with earlier classifications. We also present an identification key to the species based on the cladistic analysis.
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| 5. |
- Härlin, Mikael
(författare)
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Taxonomic names and phylogenetic trees
- 1998
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Ingår i: Zoologica Scripta. - : Wiley. - 0300-3256 .- 1463-6409. ; 27:4, s. 381-390
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Tidskriftsartikel (refereegranskat)abstract
- This paper addresses the issue of philosophy of names within the context of biological taxonomy, more specifically how names refer. By contrasting two philosophies of names, one that is based on the idea that names can be defined and one that they cannot be defined, I point out some advantages of the latter within phylogenetic systematics. Due to the changing nature of phylogenetic hypotheses, the former approach tends to rob taxonomy from its unique communicative value since a name that is defined refers to whatever fits the definition. This is particularly troublesome should the hypothesis of phylogenetic relationship change. I argue that, should we decide to accept a new phylogenetic hypothesis, it is also likely that our view of what to name may change. A system where names only refer acknowledge this, and accordingly leaves it open whether to keep a name (and accept the way it refers in the new hypothesis) or discard a name and introduce new names for the parts of the tree that we find scientifically interesting. One of the main differences between a phylogenetic system of definition (PSD) and a phylogenetic system of reference (PSR) is that the former is governed by laws of language while the latter by communicative needs of taxonomists. Thus, a PSR tends to give primacy to phylogenetic trees rather than phylogenetic definitions of names should our views of which phylogenetic hypothesis to accept change.
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| 8. |
- Ericson, Per G P, 1956-
(författare)
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Systematic relationships of the palaeogene family Presbyornithidae (Aves : Anseriformes)
- 1997
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Ingår i: Zoological Journal of the Linnean Society. - 0024-4082 .- 1096-3642. ; 121:4, s. 429-483
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Tidskriftsartikel (refereegranskat)abstract
- The early Tertiary (Paleocene and Eocene) family Presbyornithidae is one of the most completely known group of fossil birds. Essentially all parts of the skeleton are represented in the fossil record, allowing a thorough analysis of the phylogenetic position of the family. Forty-two families of nonpasserine birds representing the orders Ciconiiformes, Anseriformes, Galliformes, Gruiformes and Charadriiformes, were included in a cladistic analysis of 71 skeletal characters. The previously suggested anseriform affinity of the Presbyornithidae was confirmed. Furthermore, the family proved to be closer to the Anatidae than to the Anhimidae or Anseranatidae. The many postcranial similarities with certain charadriiform birds as the Burhinidae, obviously are plesiomorphies. By this observation, a better undestanding of character evolution in nonpasserine skeletal morphology is gained. The often suggested close relationship of anseriform and galliform birds is not confirmed by osteology. Instead, the Anseriformes and the Phoenicopteridae form a monophyletic clade that is the sister to the remaining ciconiiform birds. This result renders the Ciconiiformes sensu Wetmore (1960) polyphyletic. (C) 1997 The Linnean Society of London.
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| 9. |
- Korall, Petra, 1968-, et al.
(författare)
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Phylogeny of selaginellaceae : Evaluation of generic subgeneric relationships based on rbcL gene sequences
- 1999
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Ingår i: International journal of plant sciences. - : University of Chicago Press. - 1058-5893 .- 1537-5315. ; 160:3, s. 585-594
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Tidskriftsartikel (refereegranskat)abstract
- A cladistic analysis based on rbcL gene sequences from a representative sample of 18 species yields three most parsimonious trees that strongly support monophyly of Selaginellaceae. Within Selaginellaceae, the morphologically distinctive subgenus Selaginella is resolved as sister group to a clade composed of all other species, here termed the rhizophoric clade. In the rhizophoric clade, subgenus Stachygynandrum is paraphyletic to subgenera Ericetorum, Tetragonostachys, and Heterostachys. Monophyly of Ericetorum and Tetragonostachys is strongly corroborated. Results support a close relationship between "resurrection plants" in Stachygynandrum and the mat-forming or tufted drought-tolerant species of Tetragonostachys, indicating a common origin of xerophytism in these groups. A close relationship for all isophyllous species, as hypothesized in many classifications, is not supported by the rbcL data. Leaf isophylly and reduction in Ericetorum and Tetragonostachys most probably represent independent reversals of the marked anisophyllous condition in Stachygynandrum, Leaf reduction is one of a suite of characters that may have evolved in response to seasonal drought.
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| 10. |
- Sundin, Rikard
(författare)
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Phylogenetic and taxonomic studies within Arthonia Ach. (Ascomycetes, Arthoniales)
- 1999
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The taxonomy and phylogeny of the genus Arthonia was analysed. As a first step, a phylogenetic analysis was performed to test the monophyly of some of the infrageneric groups suggested by earlier authors. The results strongly support that Arthonia, Arthothelium and Arthoniaceae are paraphyletic. Five monophyletic clades were revealed within Arthonia. The best supported clade , Arthonia sect. Arthonia, consisted of non-lichenized or poorly lichenized pioneer species, including the type species of Arthonia, A. radiata.A taxonomic revision of this clade in Europe, northern Africa and North America is presented. Descriptions, distribution maps and photographs are given for the 27 recognised species. The systematic history of Arthonia and Arthothelium is reviewed. The morphology, anatomy, chemistry, ecology and distribution patterns of Arthonia sect. Arthonia are described. Keys are given to the genera within Arthoniaceae, to infrageneric groups within Arthonia and to the treated species. A phylogenetic analysis of the 27 recognized species is presented, based on 57 morphological, anatomical, chemical and ecological characters. The analysis resulted in 311 most parsimonious trees. In the strict consensus tree section Arthonia is monophyletic receiving a Bremer support value of two. Arthonia reniformis and A. ruana constitute the sister group of section Arthonia. Relationships within section Arthonia are not fully resolved. A new species, Arthonia tehleri, is described. The following species of Arthothelium are transferred to Arthonia sect. Arthonia: Arthothelium beccarianum (syn. A. sardoum), A. lirellans, A. orbilliferum, A. phlyctiformis (syn. A. taediosoides), and A. subastroideum. The following names have to be changed due to priority reasons: Arthonia crozalsiana (to Arthonia albopulverea), A. epipastoides (to A. glaucella), A. sardoa (to A. beccariana), Arthothelium taediosoides (to Arthonia phlyctiformis).
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