Matches in SemOpenAlex for { <https://semopenalex.org/work/W2010026934> ?p ?o ?g. }
Showing items 1 to 74 of
74
with 100 items per page.
- W2010026934 endingPage "217" @default.
- W2010026934 startingPage "197" @default.
- W2010026934 abstract "Tropical material offers special advantages for the study of evolution, since the evolutionary process has progressed in a more continuous form than in the north temperate region, not having been seriously interrupted by glaciations, nor being restricted in space. The members of the orchid family offer special advantages (a) since the family is one of the largest and probably a most recent one phylogenetically, with the taxonomy well advanced and (b) since they have a peculiar type of geographical distribution, the basic pattern, developed through slow expansion of areas, being overlaid by a secondary pattern resulting from long-distance dispersal. The problem, which will be discussed, refers to the relative importance of sympatric-central or sympatric-marginal disruptive evolution as compared to an allopatric one. Two groups of species were taken into consideration, representing two different types of phylogenetic evolution and geographic distribution. The species of bifoliate Cattleya in the Atlantic and central regions of Brazil form several pairs or chains of vicarious species with contiguous, but not overlapping distribution, and a certain overlapping occurs only in the species, C. loddigesii, and then on a subspecific level. The regularity of this behaviour seems to indicate strongly that either the species have evolved by disruptive-central (sympatric) diversification, one original species breaking up into two or more vicarious ones, or by disruptive-marginal diversification, one species changing into another at and beyond its adaptive range. C. loddigesii may thus be considered as an early stage in such a development. In the genus Oncidium only one group of species was mentioned with a very high degree of strictly sympatric diversification. The third group is formed by species of the Maxillariinae, one belonging to Trigonidium and the others to Maxillaria. One set of three species shows an extreme range of distribution: M. rufescens and M. cleistogama in nearly all the American tropics except the Amazon Basin, and T. acuminatum in the Amazon Basin and neighbouring areas. The other set was composed of the 15 species of the Sect. Pictae, with partially sympatric areas in southern, central and eastern Brazil only. The study required the use of statistical methods, and a form of sequential analysis of variance was applied. The whole area of distribution of a species was divided into regions; within regions there were the localities from which material came and the next units were the individual plants collected. The residual error of this sequence was represented by the variance of phenotypic variation between flowers within plants. If diversification should be stimulated by allopatric separation, then the error components would diminish in the sequence given, whereas if sympatric evolution is frequent, the ‘within’ errors between regions or localities need not be different. In order to minimize the phenotypic ‘within-plant’ variability, the specimens were first maintained under homogenizing conditions. The analysis was carried out for ten species, and in three an additional component was separated referring to indications of infraspecific taxonomic divisions. For the very uniform M. cleistogama the data show that there is no indication of a genetical intrapopulational variability and that geographical separation between localities in Venezuela, Peru and eastern Brazil also caused no significant increase in variability. In the case of the other two species, T. acuminatum and M. rufescens, genetic variability between plants was quite significant, and so was variation between localities. But in both species intraspecific separations were represented by the highest error, and showed a correlation with geographical distribution. This in fact was to be expected, since the vast area of distribution included different floristic-ecological areas and thus some allopatric evolution was bound to occur." @default.
- W2010026934 created "2016-06-24" @default.
- W2010026934 creator A5008028232 @default.
- W2010026934 date "1969-04-01" @default.
- W2010026934 modified "2023-09-27" @default.
- W2010026934 title "Patterns of evolutionary and geographical distribution in neotropical orchids" @default.
- W2010026934 cites W2007993714 @default.
- W2010026934 cites W4206747321 @default.
- W2010026934 doi "https://doi.org/10.1111/j.1095-8312.1969.tb01819.x" @default.
- W2010026934 hasPublicationYear "1969" @default.
- W2010026934 type Work @default.
- W2010026934 sameAs 2010026934 @default.
- W2010026934 citedByCount "5" @default.
- W2010026934 countsByYear W20100269342015 @default.
- W2010026934 countsByYear W20100269342022 @default.
- W2010026934 crossrefType "journal-article" @default.
- W2010026934 hasAuthorship W2010026934A5008028232 @default.
- W2010026934 hasConcept C104317684 @default.
- W2010026934 hasConcept C115225378 @default.
- W2010026934 hasConcept C144024400 @default.
- W2010026934 hasConcept C149923435 @default.
- W2010026934 hasConcept C159985019 @default.
- W2010026934 hasConcept C18903297 @default.
- W2010026934 hasConcept C192562407 @default.
- W2010026934 hasConcept C193252679 @default.
- W2010026934 hasConcept C204323151 @default.
- W2010026934 hasConcept C2779608229 @default.
- W2010026934 hasConcept C2908647359 @default.
- W2010026934 hasConcept C47559259 @default.
- W2010026934 hasConcept C53889494 @default.
- W2010026934 hasConcept C55493867 @default.
- W2010026934 hasConcept C68775705 @default.
- W2010026934 hasConcept C78458016 @default.
- W2010026934 hasConcept C86803240 @default.
- W2010026934 hasConcept C92274894 @default.
- W2010026934 hasConceptScore W2010026934C104317684 @default.
- W2010026934 hasConceptScore W2010026934C115225378 @default.
- W2010026934 hasConceptScore W2010026934C144024400 @default.
- W2010026934 hasConceptScore W2010026934C149923435 @default.
- W2010026934 hasConceptScore W2010026934C159985019 @default.
- W2010026934 hasConceptScore W2010026934C18903297 @default.
- W2010026934 hasConceptScore W2010026934C192562407 @default.
- W2010026934 hasConceptScore W2010026934C193252679 @default.
- W2010026934 hasConceptScore W2010026934C204323151 @default.
- W2010026934 hasConceptScore W2010026934C2779608229 @default.
- W2010026934 hasConceptScore W2010026934C2908647359 @default.
- W2010026934 hasConceptScore W2010026934C47559259 @default.
- W2010026934 hasConceptScore W2010026934C53889494 @default.
- W2010026934 hasConceptScore W2010026934C55493867 @default.
- W2010026934 hasConceptScore W2010026934C68775705 @default.
- W2010026934 hasConceptScore W2010026934C78458016 @default.
- W2010026934 hasConceptScore W2010026934C86803240 @default.
- W2010026934 hasConceptScore W2010026934C92274894 @default.
- W2010026934 hasIssue "1-2" @default.
- W2010026934 hasLocation W20100269341 @default.
- W2010026934 hasOpenAccess W2010026934 @default.
- W2010026934 hasPrimaryLocation W20100269341 @default.
- W2010026934 hasRelatedWork W1554239110 @default.
- W2010026934 hasRelatedWork W2000699432 @default.
- W2010026934 hasRelatedWork W2058972664 @default.
- W2010026934 hasRelatedWork W2074460143 @default.
- W2010026934 hasRelatedWork W2086533412 @default.
- W2010026934 hasRelatedWork W2110179596 @default.
- W2010026934 hasRelatedWork W2320113063 @default.
- W2010026934 hasRelatedWork W2613027301 @default.
- W2010026934 hasRelatedWork W3108765942 @default.
- W2010026934 hasRelatedWork W4253041405 @default.
- W2010026934 hasVolume "1" @default.
- W2010026934 isParatext "false" @default.
- W2010026934 isRetracted "false" @default.
- W2010026934 magId "2010026934" @default.
- W2010026934 workType "article" @default.