Search results for " evolution."
showing 10 items of 9653 documents
Evolution of bacterial life-history traits is sensitive to community structure
2016
Very few studies have experimentally assessed the evolutionary effects of species interactions within the same trophic level. Here we show that when Serratia marcescens evolve in multispecies communities, their growth rate exceeds the growth rate of the bacteria that evolved alone, whereas the biomass yield gets lower. In addition to the community effects per se, we found that few species in the communities caused strong effects on S. marcescens evolution. The results indicate that evolutionary responses (of a focal species) are different in communities, compared to species evolving alone. Moreover, selection can lead to very different outcomes depending on the community structure. Such con…
Chaenothecopsis schefflerae (Ascomycota: Mycocaliciales): a widespread fungus on semi-hardened exudates of endemic New Zealand Araliaceae
2017
Ascomycetes specialised to live on hardened plant exudates occur worldwide, but the number of species so far described is relatively small (c.30). Particularly within the genus Chaenothecopsis (Ascomycota:Mycocaliciales), many species produce their ascomata on hardened but still relatively fresh outpourings of conifer resin or angiosperm exudate. Temperate rainforests of New Zealand provide habitat for several endemic Chaenothecopsis species, including Chaenothecopsis schefflerae, which was previously known from a single sample collected from the exudate of Schefflera digitata (Araliaceae) in the early 1980s. Here we show that C.schefflerae is neither lost nor very rare, but occurs sporadic…
On the thermodynamic origin of metabolic scaling
2018
The origin and shape of metabolic scaling has been controversial since Kleiber found that basal metabolic rate of animals seemed to vary as a power law of their body mass with exponent 3/4, instead of 2/3, as a surface-to-volume argument predicts. The universality of exponent 3/4 -claimed in terms of the fractal properties of the nutrient network- has recently been challenged according to empirical evidence that observed a wealth of robust exponents deviating from 3/4. Here we present a conceptually simple thermodynamic framework, where the dependence of metabolic rate with body mass emerges from a trade-off between the energy dissipated as heat and the energy efficiently used by the organi…
Standardised spider (Arachnida, Araneae) inventory of Lammi, Finland
2020
In June 2019, an ecology field course of the University of Helsinki was held at Lammi Biological Station, Southern Finland. Within this course, the students familiarised themselves with field work and identification of spiders and explored the diversity of species in the area. Three sampling plots were chosen, one in grassland and two in boreal forest, to demonstrate the sampling techniques and, by applying a standardised protocol (COBRA), contribute to a global spider biodiversity project. The collected samples contained a total of 3445 spiders, of which 1956 (57%) were adult. Only adult spiders were accounted for in the inventory due to the impossibility of identification of juveniles. A …
Successive Losses of Central Immune Genes Characterize the Gadiformes' Alternate Immunity.
2016
Great genetic variability among teleost immunomes, with gene losses and expansions of central adaptive and innate components, has been discovered through genome sequencing over the last few years. Here, we demonstrate that the innate Myxovirus resistance gene (Mx) is lost from the ancestor of Gadiformes and the closely related Stylephorus chordatus, thus predating the loss of Major Histocompatibility Complex class II (MHCII) in Gadiformes. Although the functional implication of Mx loss is still unknown, we demonstrate that this loss is one of several ancient events appearing in successive order throughout the evolution of teleost immunity. In particular, we find that the loss of Toll-like r…
Ancient DNA reveals the Arctic origin of Viking Age cod from Haithabu, Germany
2017
Knowledge of the range and chronology of historic trade and long-distance transport of natural resources is essential for determining the impacts of past human activities on marine environments. However, the specific biological sources of imported fauna are often difficult to identify, in particular if species have a wide spatial distribution and lack clear osteological or isotopic differentiation between populations. Here, we report that ancient fish-bone remains, despite being porous, brittle, and light, provide an excellent source of endogenous DNA (15-46%) of sufficient quality for whole-genome reconstruction. By comparing ancient sequence data to that of modern specimens, we determine …
Notulae to the Italian alien vascular flora: 5
2018
In this contribution, new data concerning the distribution of vascular flora alien to Italy are presented. It includes new records, and confirmations for Italy or for Italian administrative regions of taxa in the genera Albizia, Anredera, Bougainvillea, Cardamine, Cenchrus, Cephalaria, Ceratochloa, Cytisus, Datura, Delosperma, Euonymus, Freesia, Hylotelephium, Lantana, Musa, Physalis, Rotala, Styphnolobium, Trachycarpus, and Tradescantia. Nomenclature and distribution updates, published elsewhere, and corrections are provided as supplementary material.
Notulae to the Italian flora of algae, bryophytes, fungi and lichens: 4
2017
In this contribution, new data concerning bryophytes, fungi and lichens of the Italian flora are presented. It includes new records and confirmations for the bryophyte generaCampylopus,Paludella,Tortula, andConocephalum, the fungal generaAgonimia,Buelliella,Entorrhiza,Filicupula,Poronia, andSporisorium, the lichen generaCladonia,Dibaeis,Lasallia, andRhizocarpon.
Notulae to the Italian flora of algae, bryophytes, fungi and lichens: 7
2019
In this contribution, new data concerning algae, bryophytes, fungi, and lichens of the Italian flora are presented. It includes new records and confirmations for the algae genusChara, the bryophyte generaCephalozia,Conardia,Conocephalum,Didymodon,Sphagnum,Tetraplodon, andTortula, the fungal generaEndophyllum,Gymnosporangium,Microbotryum,Phragmidium, andPluteus, and the lichen generaCandelariella,Cladonia,Flavoplaca,Lichenothelia,Peltigera,Placolecis,Rinodina,Scytinium, andSolenopsora.
Notulae to the Italian native vascular flora: 1
2016
In this contribution, new data concerning the Italian distribution of native vascular flora are presented. It includes new records, exclusions, and confirmations pertaining to the Italian administrative regions for taxa in the genera Arundo, Bromopsis, Cistus, Crocus, Festuca, Galeopsis, Genista, Lamium, Leucanthemum, Nerium, Orobanche, Peucedanum, Pilosella, Polycnemum, Stipa and Viola.