Search results for "Phylogenetics"

Is mate fidelity related to site fidelity? A comparative analysis in Ciconiiforms

2000

We tested for an association between divorce rate and site fidelity in 42 avian species belonging to the order Ciconiiforms, using comparative methods that account for the influences of phylogenetic relationships on the data. Our methods enabled us to detect evidence of correlated evolution and provided information on the temporal ordering of evolutionary changes in these two variables. We found a significant correlation between divorce rate and site fidelity, indicating that species with little or no site fidelity are more likely to divorce. Our data suggest that the coupled evolution of divorce and site fidelity can be summarized by three major events. The first event corresponds to a tra…

ECOLOGICAL LIMITS ON DIVERSIFICATION OF THE HIMALAYAN CORE CORVOIDEA

2012

Within regions, differences in the number of species among clades must be explained by clade age, net diversification rate, or immigration. We examine these alternatives by assessing historical causes of the low diversity of a bird parvorder in the Himalayas (the core Corvoidea, 57 species present), relative to its more species rich sister clade (the Passerida, ∼400 species present), which together comprise the oscine passerines within this region. The core Corvoidea contain ecologically diverse species spanning a large range of body sizes and elevations. Despite this diversity, on the basis of ecological, morphological, and phylogenetic information, we infer that the best explanation for t…

Ancient recruitment by chromists of green algal genes encoding enzymes for carotenoid biosynthesis.

2008

Chromist algae (stramenopiles, cryptophytes, and haptophytes) are major contributors to marine primary productivity. These eukaryotes acquired their plastid via secondary endosymbiosis, whereby an early-diverging red alga was engulfed by a protist and the plastid was retained and its associated nuclear-encoded genes were transferred to the host genome. Current data suggest, however, that chromists are paraphyletic; therefore, it remains unclear whether their plastids trace back to a single secondary endosymbiosis or, alternatively, this organelle has resulted from multiple independent events in the different chromist lineages. Both scenarios, however, predict that plastid-targeted, nucleus-…

Disentangling composite colour patterns in a poison frog species

2008

A phylogenetic approach was performed to infer whether variation in conspicuous colour-patterns of a poison frog (Dendrobatidae: Dendrobates tinctorius) has evolved neutrally or under selection. Colour and pattern were split into components that were separately analysed and subsequently re-grouped via principal component analysis. This revealed four different ‘displayed’ factors on the dorsal and lateral views versus one ‘concealed’ factor on the ventral view. Based on the assumption that current patterns of trait variation contain information about the evolutionary history of the phenotype, we correlated these trait components to a neutrally evolving gene fragment (cytochrome b). The conce…

Range size: Disentangling Current Traits and Phylogenetic and Biogeographic Factors

2006

The range size of a species can be determined by its current traits and by phylogenetic and biogeographic factors. However, only rarely have these factors been studied in combination. We use data on the geographic range sizes of all 26 Sylvia warblers to explicitly test whether range size was determined by current species-specific traits (e.g., body size, dispersal ability), phylogenetic factors (e.g., age of the lineage), or environmental, biogeographic factors (e.g., latitudinal position of the range). The results demonstrated that current traits and phylogenetic and biogeographic factors were interrelated. While a number of factors were significant in simple regression analyses, only one…

Walter Zimmermann and the Growth of Phylogenetic Theory

1992

seminal theoretical paper, "Arbeitsweise der botanischen Phylogenetik und anderer Gruppierungswissenschaften" ("Methods of botanical phylogenetics and other grouping sciences"), first published in 1931. In this paper, Zimmermann clearly ex? pressed many of the underlying principles of phylogenetic systematics?ideas that were later taken up by Hennig and formed the core of his theory. Zimmermann also focused attention on several basic meth?

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.

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…