Linking melanism to brain development: expression of a melanism-related gene in barn owl feather follicles covaries with sleep ontogeny.

BACKGROUND: Intra-specific variation in melanocyte pigmentation, common in the animal kingdom, has caught the eye of naturalists and biologists for centuries. In vertebrates, dark, eumelanin pigmentation is often genetically determined and associated with various behavioral and physiological traits, suggesting that the genes involved in melanism have far reaching pleiotropic effects. The mechanisms linking these traits remain poorly understood, and the potential involvement of developmental processes occurring in the brain early in life has not been investigated. We examined the ontogeny of rapid eye movement (REM) sleep, a state involved in brain development, in a wild population of barn owls (Tyto alba) exhibiting inter-individual variation in melanism and covarying traits. In addition to sleep, we measured melanistic feather spots and the expression of a gene in the feather follicles implicated in melanism (PCSK2). RESULTS: As in mammals, REM sleep declined with age across a period of brain development in owlets. In addition, inter-individual variation in REM sleep around this developmental trajectory was predicted by variation in PCSK2 expression in the feather follicles, with individuals expressing higher levels exhibiting a more precocial pattern characterized by less REM sleep. Finally, PCSK2 expression was positively correlated with feather spotting. CONCLUSIONS: We demonstrate that the pace of brain development, as reflected in age-related changes in REM sleep, covaries with the peripheral activation of the melanocortin system. Given its role in brain development, variation in nestling REM sleep may lead to variation in adult brain organization, and thereby contribute to the behavioral and physiological differences observed between adults expressing different degrees of melanism.

Niagara Bruce Trail Club Fonds, 1962-2014, n.d.

The Bruce trail is Canada’s longest and oldest continuous footpath. The trail runs along the Niagara Escarpment from Niagara to Tobermory through private and public land. The main trail is 890 km long and the side trails measure 400 km. In 1961, a “Save the Escarpment” conference was held in Hamilton. Gerry Wolfram, a writer for the St. Catharines Standard proposed that a committee be formed to develop a hiking trail. The Peninsula Field Naturalists Club formed a committee and President Bert Lowe contacted landowners along the proposed route to gain permission to cross their properties. Through Bert Lowe’s effort and dedication, the trail was completed in October 1963. The trail was officially opened on May 24th, 1964 in a ceremony at Queenston. The Niagara group joined the Bruce Trail Association in 1968 at which time the Niagara Bruce Trail Club was formed. The Bruce Trail Association is a charitable, membership-based volunteer organization. Their goal is to preserve public access to the Niagara Escarpment while restoring its natural habitat. The head office of the Bruce Trail Association is located in Hamilton, Ontario. The Niagara Bruce Trail Club’s goal is to secure and preserve a natural corridor along the Niagara Escarpment while providing education, awareness, and access for the public and the future. The club has organized many hikes including special hikes such as the one to commemorate the St. Catharines Centennial. The club has also hosted children’s hikes, cross country skiing hikes, wildflower hikes, jogging hikes, snowshoe hikes and bike outings. They hold annual events such as the End to End hike which is a 3 day walk from Grimsby to Queenston and the 30 km Laura Secord hike to commemorate Laura Secord’s famous walk. Charity hikes have also been held for the Heart and Stroke Foundation and the Lung Association as well as other causes. Major changes have taken place along the trail throughout the years, some of these include: a reroute which eliminated the tunnel passage (1976) and a bridge which eliminated the need to walk to Mountain Road to cross the Queen Elizabeth Way (2008). Other major changes and clean-up projects have been undertaken by the club. The Bruce Trail Conservancy (formerly Association) is made up of 9 clubs including: Niagara Bruce Trail Club (Queenston to Grimsby), Iroquia Bruce Trail Club (Grimsby to Kelso), Toronto Bruce Trail Club (Kelso to Cheltenham), Caledon Hills Bruce Trail Club (Cheltenham to Mono Centre), Dufferin Hi-Land Bruce Trail Club (Mono Centre to Lavender), Blue Mountains Bruce Trail Club (Lavender to Craigleath), Beaver Valley Bruce Trail Club (Craigleath to Blantyre), Sydenham Bruce Trail Club (Blantyre to Wiarton) and Peninsula Bruce Trail Club (Wiarton to Tobermory). Sources: http://www.niagarabrucetrail.org/index.html and http://brucetrail.org/

Joseph Banks.

Se hace un análisis tanto de la vida personal como de la trayectoria profesional e investigadora de este explorador y naturalista británico. El texto tiene distintos tipos de letra y de dificultad para motivar a los estudiantes a leer en un nivel más elevado. Tiene, además, cronología de su vida y de su época, glosario, bibliografía y direcciones web.

Charles Darwin.

Se hace un análisis tanto de la vida personal como de la trayectoria profesional e investigadora del autor de la teoría de la evolución de las especies. El texto tiene distintos tipos de letra y de dificultad para motivar a los estudiantes a leer en un nivel más elevado. Tiene, además, cronología de su vida y de su época, glosario, bibliografía y direcciones de internet.

Naturaleza, paisaje y memoria: alturas y ciudades del Reino de Qutio en la experiencia viajera del siglo XVIII (Estudios)

A mediados del siglo XVIII las alturas de los Andes del Reino de Quito, al igual que sus centros urbanos, fueron visitadas por viajeros naturalistas y misioneros. Este artículo explora cómo algunos de esos viajeros percibieron, construyeron y recordaron desde dos puntos de vista distintos la naturaleza y el paisaje. Tras exponer las categorías y enfoques empleados, el artículo explora dos tipos de percepción y memoria de la naturaleza: el sobrenatural y el naturalista. Finalmente, se analiza el paisaje urbano en cuya construcción escrita se combinaron las antiguas ideas del orden colonial con la perspectiva de la prosperidad terrenal, correlato del interés por las ciencias aplicadas que animaba la exploración de las alturas nevadas y de los volcanes.

Rensch's rule in large herbivorous mammals derived from metabolic scaling

Rensch’s rule, which states that the magnitude of sexual size dimorphism tends to increase with increasing body size, has evolved independently in three lineages of large herbivorous mammals: bovids (antelopes), cervids (deer), and macropodids (kangaroos). This pattern can be explained by a model that combines allometry,life-history theory, and energetics. The key features are thatfemale group size increases with increasing body size and that males have evolved under sexual selection to grow large enough to control these groups of females. The model predicts relationships among body size and female group size, male and female age at first breeding,death and growth rates, and energy allocation of males to produce body mass and weapons. Model predictions are well supported by data for these megaherbivores. The model suggests hypotheses for why some other sexually dimorphic taxa, such as primates and pinnipeds(seals and sea lions), do or do not conform to Rensh’s rule.

Competition and dispersal in Pseudomonas aeruginosa

Dispersal plays a crucial role in a range of evolutionary and ecological processes; hence there is strong motivation to understand its evolution. One key prediction is that the relative benefits of dispersal should be greater when dispersing away from close relatives, because in this case dispersal has the additional benefit of alleviating competition with individuals who share the same dispersal alleles. We tested this prediction for the first time using experimental populations of the opportunistic pathogen Pseudomonas aeruginosa. We measured the fitness of isogenic genotypes that differed only in their dispersal behaviors in both clonal and mixed populations. Consistent with theory, the benefit of dispersal was much higher in clonal populations, and this benefit decreased with increasing growth rate costs associated with dispersal.

Transient microgeographic clines during B chromosome invasion

The near-neutral model of B chromosome evolution predicts that the invasion of a new population should last some tens of generations, but the details on how it proceeds in real populations are mostly unknown. Trying to fill this gap, we analyze here a natural population of the grasshopper Eyprepocnemis plorans at three time points during the last 35 years. Our results show that B chromosome frequency increased significantly during this period, and that a cline observed in 1992 had disappeared in 2012 once B frequency reached an upper limit in all sites sampled. This indicates that, during B chromosome invasion, at microgeographic scale, transient clines for B frequency are formed at the invasion front. Computer simulation experiments showed that the pattern of change observed for genotypic frequencies is consistent with the existence of B chromosome drive through females and selection against individuals with high number of B chromosomes.

Intraspecific trait variation is correlated with establishment success of alien mammals

Many studies have aimed to identify common predictors of successful introductions of alien species, but the search has had limited success, particularly for animals. Past research focused primarily on mean trait values, even though genetic and phenotypic variation has been shown to play a role in establishment success in plants and some animals (mostly invertebrates). Using a global database describing 511 introduction events representing 97 mammalian species, we show that intraspecific variation in morphological traits is associated with establishment success, even when controlling for the positive effect of propagule pressure. In particular, greater establishment success is associated with more variation in adult body size but, surprisingly, less variation in neonate body size, potentially reflecting distinct trade-offs and constraints that influence population dynamics differently. We find no mean trait descriptors associated with establishment success, although species occupying wider native distribution ranges (which likely have larger niches) are more successful. Our results emphasize the importance of explicitly considering intraspecific variation to predict establishment success in animal species and generally to understand population dynamics. This understanding might improve management of alien species and increase the success of intentional releases, for example, for biocontrol or reintroductions.

Ecologia trófica em uma taxocenose de anfíbios: estrutura, filogenia e especialização individual

Historically, ever since the pre-Darwinian naturalists interspecific competition was considered the main force responsible for structuring ecological communities. This interpretation lost strength in the late 70s and throughout the 80s giving room for other views, which consider other factors such as predation, parasitism and the phylogenetic inertia more important. Studies on changes in the trophic niche of a species are still uncommon in general and especially in amphibians. Species considered generalist might actually be a group of individual specialists, or individuals that specialize in a particular category of prey during a period of scarcity of resources, thus reducing intraspecific competition. This work studied the community structure of litter amphibians and trophic variation along the dry and rainy seasons in a population of Leptodactylus macrosternum. Sixteen-litter frog species were studied for their diet. Two central assumptions were tested: 1a) if the community is structured in the niche trophic level, and 1b) if there is a significant difference in the use of food resources by different species (i.e. if the community is structured), the observed structure is the result of ecological interactions or just the current phylogenetic inertia of species. Finally, 2) if there is variation in food resource use between seasons for L. macrosternum. The community showed a structure with respect to the use of food resources, and this structure persisted after taking into account the phylogenetic relationships among species. The diet of Leptodactylus macrosternum varied with the seasons, with a significant degree of individual specialization for the dry season. Patterns of a local community are important to understand its dynamics, and this may play a role in larger- scale processes. Therefore, the studies in community ecology are fundamental to understand and eventually restoring degraded areas

Phylogeny of leafcutter ants in the genus Atta Fabricius (Formicidae: Attini) based on mitochondrial and nuclear DNA sequences

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Aves colecionadas na localidade de Fazenda Caiuá (Paraná, Brasil) por Adolph Hempel, com discussão sobre a sua localizaç ão exata

The region known as the pioneer north of Paraná State can be considered one of the most severely modified in southern Brazil, due to the colonization that started at the end of 19th century. In this little known region, seldom visited by traveler naturalists of the past, the collector Adolph Hempel obtained an important series of bird specimens that constitute, in many cases, the only - and last - information concerning the avifauna of this region. For several reasons, Fazenda Cayoá has been associated with the State of São Paulo, although it was an important center for coffee in the early 20th. century and is near the left bank of Rio Paranapanema, thus in the State of Paraná.

Natureza apropriada: a exploração dos recursos naturais na capitania de Santa Catarina (1738-1808)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A prática vegetariana em Rio Claro: corpo, espírito e natureza

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A Biogeografia no núcleo de Rio Claro (SP): análise e avaliação das contribuições científicas no período de 1969-2004

Pós-graduação em Geografia - IGCE