Search results for "PHYLOGENE"

Ontogenetic and phylogenetic diversification of the hooded staminode in Marantaceae

2010

The flowers of Marantaceae are known for their unique pollination mechanism mediated by an explosive style movement. The mechanism is based on the highly modified elements of the inner androecial whorl, i.e., the single half-fertile anther and the fleshy and hooded staminodes. We investigated 67 species across 24 genera to elucidate which parts of the hooded staminode are shared by all species, thus likely under strong selection pressure, and which are allowed to vary. We treated hooded staminodes as character syndromes and grouped them based on gross similarities. We identified characters underlying the similarity and investigated their diversity and developmental pathways. All hooded stam…

2006

We describe for the first time the radial sesamoid or “false thumb” of the spectacled bear (Tremarctos ornatus), showing its great morphological similarities with that of the giant panda (Ailuropoda melanoleuca) and the differences with that of the rest of the Ursidae. This points to the existence of a common origin for this structure in both species, but considering the accepted phylogenies of ursids, the sharing of a “false thumb” in T. ornatus and A. melanoleuca would be a plesiomorphy for these groups, whereas in the rest of the ursids the radial sesamoid was probably reduced, lacking the specialised function that this bone has in Tremarctinae and Ailuropodinae.

Classification of Primula sect. Auricula (Primulaceae) based on two molecular data sets (ITS, AFLPs), morphology and geographical distribution

2004

On the basis of the study of c. 1100 herbarium specimens, field observations and molecular (ITS, AFLPs) evidence, Primula sect. Auricula is classified into two subsections, 25 species and six subspecies. Primula auricula L. ssp. widmerae (Pax) L. B. Zhang stat. nov., P. auricula Linn. ssp. tatriaca L. B. Zhang ssp. nov., and P. latifolia Lapeyr. ssp. cynoglossifolia (Widmer) L. B. Zhang stat. nov. are newly described or combined; P. auricula s.l. is divided into two species: P. auricula Linn. and P. balbisii Lehm., representing the northern and the southern populations of P. auricula s.l. resolved in the molecular study, respectively; P. cottia Widmer and P. balbisii Lehm. are recovered fro…

A new combination in Mononeuria (Caryophyllaceae)

2018

The nomenclatural change Mononeuria caroliniana comb. nov. is proposed on the basis of molecular phylogenetic results analyzing the nuclear internal transcribed spacer.

Phylogenetic relationships among Flavescence doree strains and related phytoplasmas determined by heteroduplex mobility assay and sequence of ribosom…

2003

Heteroduplex mobility assay (HMA) and DNA sequencing were performed on Flavescence doree (FD) phytoplasma strains and related phytoplasmas belonging to the elm yellows group. Part of the ribosomal RNA gene operon and a nonribosomal DNA region were utilized for phylogenetic analyses. Two FD strains, FD92 and FD-D, detected in France and Italy, respectively, were identical in both DNA fragments, confirming previous results. Other FD strains were all very similar and most closely resembled ALY, an Italian alder phytoplasma. Phytoplasmas associated with German Palatinate grapevine yellows were shown to form a distinct subcluster, also different from the elm yellows phytoplasma subcluster. Strai…

Phylogeny and ecological diversification of South African Sarcocornia (Chenopodiaceae)

2007

Combining ontogenetic and evolutionary scales of morphological disparity: a study of early Jurassic ammonites

2007

SUMMARY Two major research themes in Evolutionary Developmental Biology and in Paleobiology, respectively, have each become central for the analysis and interpretation of morphological changes in evolution: the study of ontogeny/ phylogeny connections, mainly within the widespread and controversial framework of heterochrony; and the study of morphological disparity, the morphological signal of biodiversity, describing secular changes in morphospace occupation during the history of any given clade. Although enriching in their respective fields, these two themes have remained rather isolated to date, despite the potential value of integrating them as some recent studies begin to suggest. Here…

Genetics on Invasive Species

2002

Genetic markers are especially appropriate to reveal historical processes, as for example regarding biological invasions. Phylogenetic and population genetic methods enable to identify the taxa involved in an invasion (native and non-native species) and often lead to the perception of multiple or cryptic invasions. Phylogeographic and multi-locus approaches have been developed to assign individual invaders to potential source populations. The results may have implications for management measures. However, little is known about the genetic architecture of newly colonised populations. We introduce here genetic models for colonisations in linear habitats like rivers or coastlines. The expectat…

Spatial and Temporal Patterns in the Evolution of the Flora of the European Alpine System

2003

This paper presents a perspective of how phylogenetic and phylogeographic hypotheses, based on nuclear DNA sequence variation (ITS) or amplified fragment length polymorphisms (AFLPs), can provide insights into the origin and evolution of the European high mountain flora. We focus on a diversity of unrelated herbaceous plant taxa that are broadly co-distributed across the European Alpine System, representing different taxonomic levels, and having either Mediterranean or Asian affinities (i.e., Anthyllis montana, Pritzelago alpina, Globularia vs. Soldanella, and Primula sect. Auricula). Our observations highlight that all taxa investigated began to diversify at the beginning of the Pleistocen…

Molecular phylogeny of Metazoa (animals): monophyletic origin.

1995

The phylogenetic relationships within the kingdom Animalia (Metazoa) have long been questioned. Focusing on the lowest eukaryotic multicellular organisms, the metazoan phylum Porifera (sponges), it remained unsolved if they evolved multicellularity independently from a separate protist lineage (polyphyly of animals) of derived from the same protist group as the other animal phyla (monophyly). After having analyzed genes typical for multicellularity (adhesion molecules/receptors and a nuclear receptor), we present evidence that Porifera should be placed in the kingdom Animalia. We therefore suggest a monophyletic origin for all animals.