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The evolution and classification of flowering plants

01 Jan 1968-
TL;DR: The evolution and classification of flowering plants is studied in detail in the book “Flowering plants: Evolution and Classification of Flowers, 2nd Ed.” (2003).
Abstract: The evolution and classification of flowering plants , The evolution and classification of flowering plants , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی
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Journal ArticleDOI
TL;DR: A common pattern of phylogenetic conservatism in ecological character is recognized and the challenges of using phylogenies of partial lineages are highlighted and phylogenetic approaches to three emergent properties of communities: species diversity, relative abundance distributions, and range sizes are reviewed.
Abstract: ▪ Abstract As better phylogenetic hypotheses become available for many groups of organisms, studies in community ecology can be informed by knowledge of the evolutionary relationships among coexisting species. We note three primary approaches to integrating phylogenetic information into studies of community organization: 1. examining the phylogenetic structure of community assemblages, 2. exploring the phylogenetic basis of community niche structure, and 3. adding a community context to studies of trait evolution and biogeography. We recognize a common pattern of phylogenetic conservatism in ecological character and highlight the challenges of using phylogenies of partial lineages. We also review phylogenetic approaches to three emergent properties of communities: species diversity, relative abundance distributions, and range sizes. Methodological advances in phylogenetic supertree construction, character reconstruction, null models for community assembly and character evolution, and metrics of community ...

3,615 citations

Journal ArticleDOI
TL;DR: This review describes and discusses several approaches to selecting higher plants as candidates for drug development with the greatest possibility of success and identifies and discusses advantages and disadvantages of using plants as starting points for drugDevelopment, specifically those used in traditional medicine.
Abstract: In this review we describe and discuss several approaches to selecting higher plants as candidates for drug development with the greatest possibility of success. We emphasize the role of information derived from various systems of traditional medicine (ethnomedicine) and its utility for drug discovery purposes. We have identified 122 compounds of defined structure, obtained from only 94 species of plants, that are used globally as drugs and demonstrate that 80% of these have had an ethnomedical use identical or related to the current use of the active elements of the plant. We identify and discuss advantages and disadvantages of using plants as starting points for drug development, specifically those used in traditional medicine.

1,992 citations

Journal ArticleDOI
06 Feb 2014-Nature
TL;DR: It is shown that woody clades successfully moved into freezing-prone environments by either possessing transport networks of small safe conduits and/or shutting down hydraulic function by dropping leaves during freezing.
Abstract: Early flowering plants are thought to have been woody species restricted to warm habitats 1–3 . This lineage has since radiated into almost every climate, with manifold growth forms 4 . As angiosperms spread and climate changed, they evolved mechanisms to cope with episodic freezing. To explore the evolution of traits underpinning the ability to persist in freezing conditions, we assembled a large species-level database of growth habit (woody or herbaceous; 49,064 species), as well as leaf phenology (evergreen or deciduous), diameter of hydraulic conduits (that is, xylem vessels and tracheids) and climate occupancies (exposure to freezing). To model the evolution of species’ traits and climate occupancies, we combined these data with an unparalleled dated molecular phylogeny (32,223 species) for land plants. Here we show that woody clades successfully move di nto freezingprone environments by either possessing transport networks of small

1,221 citations

Journal ArticleDOI
TL;DR: In angiosperms, the adaptive significance of differences between most higher categories, as well as between a large proportion of related species, is most probably associated with reproductive efficiency and successful establishment of seedlings rather than with any of the morphological characteristics of the vegetative parts.
Abstract: The overwhelming majority of biologists who have studied both the origin of races and species and major trends of evolution in animals have reached the conclusion, in agreement with Darwin, that these visible evolutionary changes are based upon shifts in adaptive systems, guided by natural selection (30, 31, 94, 117, 120). The evidence is convincing for all phyla of animals that have been carefully studied. In plants, however, the situation is much less clear, and a wide spectrum of opinions has been expressed during the past twenty years. With respect to the origin of races and of many species that occupy different habitats from those of their nearest relatives, the evidence for divergent adaptation guided by natural selection is as convincing for plants as it is for animals (20, 50, 127). On the other hand, botanists' opinions are still divided wtih respect to the role of natural selection in the origin of genera, families, and other higher categories. Good (42) has expressed in strong terms his belief that the diversity of floral types present in angiosperms evolved independently of adaptation and selection, and Nelson (99) has presented a similar point of view. Neither of these authors discussed the genetic mechanisms that might be involved. Both Cronquist (22, 23) and Werth (135) believe that the principal guiding force has been differential directed mutation. In Cronquist's words (23, pp. 120-21): "The influence of differential mutation is often so strong that a group appears to be predisposed to evolve in a certain direction." A noteworthy feature of both his general interpretation (p. 118) and his references to possible adaptive characteristics of individual families that are scattered throughout his book is that he apparently equates adaptation largely with the survival value of the adult plant. One of the principal objectives of this review is to point out the fallacy of this viewpoint, since it is probably held by the majority of plant taxonomists. In angiosperms, the adaptive significance of differences between most higher categories, as well as between a large proportion of related species, is most probably associated with reproductive efficiency and successful establishment of seedlings rather than with any of the morphological characteristics of the vegetative parts. The latter point of view has been maintained by botanists who have

986 citations

Journal ArticleDOI
TL;DR: Dioecy appears to have evolved most frequently via monoecy, perhaps through divergent adjustments of floral sex ratios between individual plants, as revealed by multivariate analysis.
Abstract: Considerable ffort has been spent documenting correlations between dioecy and various ecological and morphological traits for the purpose of testing hypotheses about conditions that favor dioecy. The data analyzed in these studies, with few exceptions, come from local floras, within which it was possible to contrast he subsets of dioecious and nondioecious taxa with regard to the traits in question. However, if there is a strong phylogenetic component o the presence or absence of dioecy, regional sampling may result in spurious associations. Here, we report results of a categorical multivariate analysis of the strengths ofvarious associations of dioecy with other traits over all flowering plants. Families were scored for presence of absence of monoecy or dioecy, systematic position, numbers of species and genera, growth forms, modes of pollination and dispersal, geographic distribution, and trophic status. Seven percent of angiosperm genera (959 of 13,500) contain at least some dioecious species, and ;6% of angiosperm species (14,620 of 240,000) are dioecious. The most consistent associations in the data set relate the presence of dioecy to monoecy, wind or water pollination, and climbing rowth. At both the family and the genus level, insect pollination is underrepresented among dioecious plants. At the family level, a positive correlation between dioecy and woody growth results primarily from the association between dioecy and climbing growth (whether woody or herbaceous) because neither the tree nor the shrub growth forms alone are consistently correlated with a family's tendency to include dioecious members. Dioecy appears to have evolved most frequently via monoecy, perhaps through divergent adjustments of floral sex ratios between individual plants. Monoecy itself is related to abiotic pollination and climbing rowth as revealed by multivariate analysis. Dioecy and monoecy are concentrated in the less advanced superorders of Thorne (1992) and subclasses of Cronquist (1988). The frequency of dioecy found in a local flora therefore flects the level of dioecy in its particular pool of families as much as, or more than, local selective factors. The positive associations of dioecy with abiotic pollination and monoecy are related to floral developmental nd morphological attributes, as is the negative association with bird and bat pollination; the positive association of dioecy with climbing growth is tentatively explained in terms of differential se ection for optimal resource allocation to sexual function. If rapid upward growth is at a premium in climbers and if fruit set at least temporarily inhibits growth or requires the production of thicker, more slowly growing stems to support heavy fruits, itmight be advantageous to postpone femaleness. Ifthe effect is strong, this may favor male plants.

861 citations