Search results for "Tropic"
showing 10 items of 1375 documents
Staying cool: preadaptation to temperate climates required for colonising tropical alpine-like environments.
2018
Plant species tend to retain their ancestral ecology, responding to temporal, geographic and climatic changes by tracking suitable habitats rather than adapting to novel conditions. Nevertheless, transitions into different environments or biomes still seem to be common. Especially intriguing are the tropical alpine-like areas found on only the highest mountainous regions surrounded by tropical environments. Tropical mountains are hotspots of biodiversity, often with striking degrees of endemism at higher elevations. On these mountains, steep environmental gradients and high habitat heterogeneity within small spaces coincide with astounding species diversity of great conservation value. The …
Parallel diversifications of Cremastosperma and mosannona (annonaceae), tropical rainforest trees tracking neogene upheaval of South America
2018
Much of the immense present day biological diversity of Neotropical rainforests originated from the Miocene onwards, a period of geological and ecological upheaval in South America. We assess the impact of the Andean orogeny, drainage of Lake Pebas and closure of the Panama isthmus on two clades of tropical trees ( Cremastosperma , ca 31 spp.; and Mosannona , ca 14 spp.; both Annonaceae). Phylogenetic inference revealed similar patterns of geographically restricted clades and molecular dating showed diversifications in the different areas occurred in parallel, with timing consistent with Andean vicariance and Central American geodispersal. Ecological niche modelling approaches show phyloge…
Dual colonization of the Palaearctic from different regions in the Afrotropics bySenecio
2016
Aim Investigation of the geographical origin of Senecio and the colonization of the Palaearctic including the relationship of life-history strategy and elevational distribution in the source area and the colonized area. Location Worldwide with a focus on the Afrotropic and the Palaearctic. Methods Sampling focused on adding species from the Afrotropic to existing datasets of Senecio. Two nuclear markers and three chloroplast markers were amplified and sequenced. Maximum likelihood and Bayesian inference were used to infer phylogeny, divergence times, biogeographical history and life-history strategy evolution. Results Senecio originated most likely during the Mid to Late Miocene in western …
A genetic study on subtropical Anadenanthera colubrina (Vell.) Brenan var. cebil (Griseb.) Altschul tree from Northwestern Argentina
2017
Anadenanthera colubrina (Vell.) Brenan var. cebil (Griseb.) Altschul is a tree species in South America important for its cultural, economic, and medicinal uses. In addition, it represents a trace in memory of the forests that have decreased over the years and for this reason it is not only interesting to study but also important to preserve the tree species for future generations. In this paper, we have characterized the genetic diversity of four populations. We collected seeds from four different sites: San Bernardo (B), El Cebilar (C), Metán (M), and El Gallinato (G) in Salta Province, North Argentina. We then compared the intergenic transcribed sequences of ribosomal DNA, a known geneti…
Marine Cryptophytes Are Great Sources of EPA and DHA
2017
Microalgae have the ability to synthetize many compounds, some of which have been recognized as a source of functional ingredients for nutraceuticals with positive health effects. One well-known example is the long-chain polyunsaturated fatty acids (PUFAs), which are essential for human nutrition. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are the two most important long-chain omega-3 (-3) PUFAs involved in human physiology, and both industries are almost exclusively based on microalgae. In addition, algae produce phytosterols that reduce serum cholesterol. Here we determined the growth rates, biomass yields, PUFA and sterol content, and daily gain of eight strains of marine…
Neotropical primate evolution and phylogenetic reconstruction using chromosomal data
2017
Platyrrhini are a group of Neotropical primates living in central and south America, and have been extensively studied through morphological and molecular data in order to shed light on their phylogeny and evolution. Agreement on the main clades of Neotropical primates has been reached using different approaches, but many phylogenetic nodes remain under discussion. Contrasting hypotheses have been proposed, presumably due to different markers and the presence of polymorphisms in the features considered; furthermore, neither Neotropical primate biodiversity nor their taxonomy are entirely known. In our perspective, a cytogenetic approach can help by making an important contribution to the ev…
A Migratory Divide Among Red-Necked Phalaropes in the Western Palearctic Reveals Contrasting Migration and Wintering Movement Strategies
2019
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Visible implant elastomer (VIE) success in early larval stages of a tropical amphibian species
2020
AbstractAnimals are often difficult to distinguish at an individual level, but being able to identify individuals can be crucial in ecological or behavioral studies. In response to this challenge, biologists have developed a range of marking (tattoos, brands, toe-clips) and tagging (PIT, VIA, VIE) methods to identify individuals and cohorts. Animals with complex life cycles are notoriously hard to mark because of the distortion or loss of the tag across metamorphosis. In frogs, few studies have attempted larval tagging and none have been conducted on a tropical species. Here, we present the first successful account of VIE tagging in early larval stages (Gosner stage 25) of the dyeing poison…
Forest Fragmentation and Selective Logging Have Inconsistent Effects on Multiple Animal-Mediated Ecosystem Processes in a Tropical Forest
2011
Forest fragmentation and selective logging are two main drivers of global environmental change and modify biodiversity and environmental conditions in many tropical forests. The consequences of these changes for the functioning of tropical forest ecosystems have rarely been explored in a comprehensive approach. In a Kenyan rainforest, we studied six animal-mediated ecosystem processes and recorded species richness and community composition of all animal taxa involved in these processes. We used linear models and a formal meta-analysis to test whether forest fragmentation and selective logging affected ecosystem processes and biodiversity and used structural equation models to disentangle di…
Revision of the pentacrinid stalked crinoids of the genus Endoxocrinus (Echinodermata, Crinoidea), with a study of environmental control of character…
2006
A revision of the stalked crinoid species attributed to the genus Endoxocrinus A.H. Clark, 1908 (Diplocrininae, Pentacrinitidae, Crinoidea, Echinodermata) is conducted using studies on phenotype variation and its relation with environment. Specimens collected via submersible at five sites in the Bahamas exhibit distinct phenotypes that correlate with different apparent ecological niches and serve as references for interpreting specimens dredged in Atlantic and Pacific Oceans where detailed information on their benthic environment is unknown. Documentation of ecophenotypic convergences or divergences allows us to distinguish between adaptive characters and those revealing genetic affinities,…