20 agosto 2009
The Tasmanian Devil (Sarcophilus harrisii) is the largest extant carnivorous marsupial. Its populations have suffered severe declines due to an infectious cancer, the devil facial tumour disease (DFTD). DFTD is an aggressive non-viral transmittable parasitic cancer. It produces facial tumors that interfere with feeding, and the affected animal starve to death. DFTD has ravaged Tasmania's wild devils, with declines up to 50% of the population.
Determining exactly how the animals interact could improve control efforts, but few studies have managed to reproduce social networks. Rodrigo K. Hamede and colleagues of the School of Zoology of the University of Tasmania, Australia, have just published in Ecology Letters their research on the structure of the contact network between individuals, a key factor on the transmission of infectious disease.
These researchers used a novel technology, proximity sensing radio collars, that detects when two animals came close to each other. These collars were fitted into 27 devils. Results indicate that all studied devils were connected in a single giant component. Since all animals are therefore connected directly or indirectly to every other animal, diseases would easily spread throughout the network from any single infected individual. More male-female contact occurred during mating season, while females interacted more frequently with females during non-mating periods.
These results suggest that there is limited potential to control the disease by targeting highly connected age or sex classes. The team was unable to find one sex or age group that had more connections than others. That information might have allowed control programs to stanch the spread of disease by targeting the most connected class.
Photographs: Wikipedia & author
Access the scientific article: Hamede, R.K. et al. 2009. Contact networks in a wild Tasmanian devil (Sarcophilus harrisii) population: using social network analysis to reveal seasonal variability in social behaviour and its implications for transmission of devil facial tumour disease. Ecology Letters DOI: 10.1111/j.1461-0248.2009.01370.x
See Journal Watch Online Blog Entry: http://journalwatch.conservationmagazine.org/2009/08/20/ties-that-bite/
EL Demonio de Tasmania (Sarcophilus harrisii) es el mayor marsupial carnívoro viviente. Sus poblaciones han sufrido severas disminuciones debido a un cancer infeccioso, el tumor facial de los demonios (devil facial tumour disease, abreviado DFTD). El DFTD es un cancer parasítico transmisible no-viral muy agresivo. Produce tumores faciles que interfieren con la alimentación y los animales afectados mueren de hambre. El DFTD ha arrasado con los demonios de Tasmania, con disminuciones poblacionales de hasta 50%.
Determinar exactamente cómo los animales interactuan podría mejorar los esfuerzos de control, pero pocos estudios han podido reproducir las redes sociales. Rodrigo K. Hamede y colegas de la Escuela de Zoología de la Universidad de Tasmania, Australia, han recientemente publicado en la revista científica Ecology Letters su estudio sobre la estructura de las redes de contacto entre individuos, un factor clave en la transmisión de enfermedades infecciosas.
Estos investigadores han usado una nueva técnología, collares de radio con sensores de proximidad que detectan cuando dos animales se acercan. Estos collares fueron colocados en 27 demonios. Los resultados indican que todos los demonios estudiados estuvieron conectados en un solo componente gigante. Dado que todos los animales están por lo tanto ligados directa o indirectamente entre sí, enfermedades podrían rapidamente extenderse dentro de la red desde cualquier individuo infectado. Mayor cantidad de contactos macho-hembra fueron observados durante la temporada de apareamiento, mientras que las hembras interactuaron más frecuentemente durante el resto del tiempo.
Estos resultados sugieren que hay un limitado potencial para controlar la enfermedad al enfocarse en clases sexuales o de edades altamente conectadas. El equipo no pudo encontrar un sexo o grupo de edad que tuvieren más conexiones que otro. Esta información hubiese podido permitir programas de control para bloquear la diseminación de la enfermedad al enfocarse en la clase más conectada.
Acceder al artículo científico:
Hamede, R.K. et al. 2009. Contact networks in a wild Tasmanian devil (Sarcophilus harrisii) population: using social network analysis to reveal seasonal variability in social behaviour and its implications for transmission of devil facial tumour disease. Ecology Letters DOI: 10.1111/j.1461-0248.2009.01370.x
Lea el blog Journal Watch Online de este artículo:http://journalwatch.conservationmagazine.org/2009/08/20/ties-that-bite/
18 agosto 2009
Darwin did not visit the volcano on his travels to the Ecuadorian Archipelago of Galapagos in the 1830s, and the Galapagos Pink Iguana was only first observed in 1986, when park rangers of the Galapagos National Park climbed Wolf Volcano and observed 5 pink iguanas with dark marks. Initially, they were thought to be some intra-population variation or even stained by some substance. But, when studies took body measurements and blood samples from 36 individuals, morphological and genetic analysis confirmed that they were an undescribed new species.
This new species differs in its morphology, behaviour, and genetics from the other two Galapagos Land Iguanas, Conolophus subcristatus and Conolophus pallidus, which are usually brown coloured.
Besides the taxonomic implications of this discovery, the Pink Iguana is extremely important as it is the only evidence of deep divergence within the Galápagos land iguana lineage. In fact, the new species carries an ancient evolutionary legacy, being the only remnant of a lineage originated when the Galápagos archipelago did not have its present geography and configuration.
This new species is endemic to the Wolf Volcano, the highest of the Galapagos. It is estimated than less than 200 adult individuals are alive. Feral cats introduced to the island may be eating the young reptiles and goats may be competitors for food. Thus, the Galapagos Pink Iguana is Critically Threated by Extinction.
The description of this new species was published by Gabriele Gentile of Università Tor Vergata (Roma, Italia) and Howard Snell of University of New Mexico (Albuquerque, USA) in the scientific journal Zootaxa of 18 August 2009.
Citation of the scientific article:
Gentile, G. & Snell, H. (2009) Conolophus marthae sp.nov. (Squamata, Iguanidae), a new species of land iguana from the Galápagos archipelago. Zootaxa, 2201, 1–10.
Download the PDF of the article: http://www.mapress.com/zootaxa/2009/f/zt02201p010.pdf
Potography: Gabrielle Gentile
La Iguana Rosada de Galápagos fue observada por primera vez en 1986 cuando oficiales del Parque Nacional Galápagos subieron al volcán Wolf y observaron 5 iguanas rosadas con marcas negras. Inicialmente pensaron que los individuos estaban manchados por alguna sustancia o que correspondian a alguna variación inter-poblacional. Sin embargo, cuando estudios posteriores tomaron datos corporales y muestras de sangre de 36 individuals, los análisis morfológicos y genéticos confirmaron que se trataba de una especie diferente y nunca antes reportada.
Esta nueva especie difiere en su morfología, compartamiento y génetica de las otras dos especies de Iguanas Terrestres de Galapagos, llamadas Conolophus subcristatus y Conolophus pallidus, que suelen ser de color café.
Además de las implicaciones taxonómicas de este descubrimiento, la Iguana Rosada es muy importante desde un punto de vista evolutivo pues representa la única evidencia de una profunda divergencia en el linaje de las Iguanas Terrestres de Galápagos. De hecho, la Iguana Rosada tiene un legado evolutivo tán antiguo que precede la actual geografía y configuración de las islas Galápagos.
Esta nueva especie habita únicamente en el Volcán Wolf, el más alto del archipelago. Se estima que existen en total menos de 200 individuos vivos, por lo que la Iguana Rosada de Galápagos es una especie en Crítico Peligro de Extinción.
La descripción de esta nueva especie fue publicada por Gabriele Gentile de la Università Tor Vergata (Roma, Italia) y por Howard Snell de la Universidad de Nuevo México (Albuquerque, USA) en la revista científica Zootaxa del 18 de Agosto 2009.
Cita del artículo científico:
Gentile, G. & Snell, H. (2009) Conolophus marthae sp.nov. (Squamata, Iguanidae), a new species of land iguana from the Galápagos archipelago. Zootaxa, 2201, 1–10.
Fotografía: Gabrielle Gentile
17 agosto 2009
The World Summit on Evolution is the largest gathering of evolutionary scientists, each time with more than 150 participants. It has been called "The Woodstock of Evolution", bringing together experts and students from widely different areas of evolutionary biology that rarely have the chance to meet. Some of the world most-famous researchers working on evolution have participated, including Peter and Rosemary Grant, Niles Eldredge, Antonio Lazcano, Douglas Futuyma, Lynn Margulis, Ada Yonath, William H. Calvin, Daniel Dennett, among others.
Evolution is the natural process responsible for the huge diversity of life in our planet and has deep implications in all aspects of humanity. Evolutionary biology studies have been key factors for the development of novel source materials for the industry, for the prevention and control of infectious diseases, and for the design of new conservation strategies. The Galapagos Islands are not important just because of Darwin’s discoveries. An impressive amount of scientific studies have been developed over the years after his visit. As information increases on the flora and fauna of the islands and their ecological patterns, it is clear that the Galapagos are a living laboratory of evolution.
The goals of the summit are to join experts from different branches of evolutionary biology to discuss on the impacts of recent discoveries in order to integrate them inside the basic concepts of evolution. Also, to remind to the scientific community on the importance of the Galapagos Islands and the discoveries produced thanks to their particular natural resources. This summit will present the islands as a living and dynamic laboratory of evolution. And of course, promoting Ecuador, its researcher, and its academic institutions working to develop scientific knowledge.
The main subjects discussed during the Second World Summit on Evolution are:
- Origin of life.
- Evolution of plants and animals.
- Human Evolution.
- Evolution and infectious diseases.
- Evolution vs. creationism/ID: An entire session of the summit focuses directly on containing the spread of creationism and intelligent design while improving the public’s understanding of evolution throughout America and elsewhere.
Dates: 22 to 26 August 2009
Place: Campus GAIAS-USFQ and Conventions Centre of the Puerto Baquerizo Moreno Municipality, San Cristobal Island, province of Galápagos, Ecuador
Further information: http://wse2.usfq.edu.ec
Universidad San Francisco de Quito
Universidad San Francisco de Quito (USFQ) is an Ecuadorian private non-profit liberal-arts university. Founded in 1988 by the Corporación de Promoción Universitaria (CPU)--its umbrella non-profit foundation, USFQ was the first totally private self-financed university in Ecuador. USFQ has a strong academic reputation, and in 2009 it was ranked 1st in Ecuador in relation to the number of peer-reviewed scientific publication. USFQ employs about half of the PhDs in Ecuador. USFQ is officially recognised by the Ministry of Education of Ecuador and accredited by CONESUP.
World Summit on Evolution
The World Summit on Evolution is an evolutionary biology meeting hosted at the Galapagos Islands by Universidad San Francisco de Quito USFQ. Its focus is on recent research and new advances in our understanding of evolution and the diversity of life. The First World Summit on Evolution took place between 09 and 12 June 2005 at the Galapagos Islands, it was widely-publicised by the most important national and international media.
The World Summit on Evolution takes place at GAIAS, The Galapagos Academic Institute for the Arts and Sciences), an institute part of the Universidad San Francisco de Quito. GAIAS was established in 2002 at the capital town of the Galapagos province, Puerto Baquerizo Moreno, on the island of San Cristobal, one of the largest of the Galapagos Island. The 4.5 hectares GAIAS campus is the only university campus on the Galapagos islands. GAIAS was founded on the principle that beyond being a college and center for the promotion and advancement of evolutionary science in Ecuador, it will become a first-rate institution for international students and researchers.
Vía: Sicrono y PuntoGeek
15 agosto 2009
When Messel Pit was located at the present latitude of Sicily, it was home to a very special fauna, including the primeval horse and the ancestors of today’s birds. 47 million years ago Messel was covered by dense primeval forests with warm, wet climate. Surveys by the Senckenberg Research Institute carries out in the Messel Pit, a UNESCO World Natural Heritage Site, have discovered about 3,000 fossil remains, including some beautiful and interesting animals:
A reptile about 80 centimetres long, the bulldog of the lizard world, closely related to the Gila monsters (Helodermatidae), a family found today just in southwestern USA and Central America. These lizards are renowned by being venomous.
Jewel beetles of the family Buprestidae, whose living representatives can now only be found in the Tropics. “The exquisite coloration is created by refraction at different layers of the chitin carapace,” explains Dr. Sonja Wedmann.
A rodent of the genus Masillamys recovered nearly whole, allowing identification of the fossilised remains of its stomach contents. The extremely well-preserved outlines of the body reveals this ancient rodent had a thick, short-haired coat of fur. The short legs typical of the genus suggest it once lived on the floor of the primeval forest surrounding Messel.
Among the mammals found, the famous Leptictidium auderiense, star among the Messel fossils thanks to the BBC documentary "Walking with Beasts". Leptictidium had a highly specialised locomotor system. Its extraordinarily long tail with 40 vertebrae, long back legs and reduced front ones point to a bipedal gait.
Fossil of Leptictidium (Wikipedia)
Leptictidium as reconstructed in BBC documentary "Walking with Beasts".
Among the total of 6,773 finds recovered at Messel Pit in 2007 and 2008, there were 1,929 fossilised remains of vertebrates, 1,403 insects and 3,441 plant remains. The information contained in the finds provide the scientists of the Senckenberg Research Institute data on the occurrence of individual species, their bodily structures and lifestyles, and the evolutionary history of animal groups. In addition, the research results help to reconstruct the Eocene environment and give clues to the relationship between climate and biodiversity.
Based on information provided by the Senckenberg Research Institute and Natural History Museum, to whom credit for all images goes to.
Full news at Discovery Channel: http://blogs.discovery.com/news_animal/2009/08/prehistoric-gila-monster-furrycoated-rodent-and-more-unearthed.html
14 agosto 2009
In areas of Canada where loggers have chewed away the conifer forest that once blanketed most of the country, the long wing feathers, or primary feathers, of 21 mature-woodland species of birds has overall gained about 2.23 millimeters on average during the past century. That uptick roughly matches the magnitude of differences between sexes. In contrast, species from areas in New England (deforested during previous years but rebounded into green woodland again) have a trend back toward rounder wing tips. Eight mature-woodland species had lost, on average, some 2.37 millimeters on those long primary feathers.
"Birds aren’t passive victims of environmental change. As bird species face new challenges, they respond to the extent they can. Birds are not like sitting ducks," said André Desrochers of the Center for Forest Research at Laval University in Québec City during a report he presented on August 13 in Philadelphia at a meeting of the American Ornithologists’ Union..
Desrochers argues that rapid evolution is the most straightforward explanation for his findings.
By ScienceNews, contributed by Susan Milius
Read full story at: http://www.sciencenews.org/view/generic/id/46471/title/Rapid_evolution_may_be_reshaping_forest_birds%E2%80%99_wings
The bird ‘skins’ were stolen on Wednesday 24 June 2009. The specimens stolen comprise a number of brightly-coloured tropical birds, like cotingas and paradise-birds, some of which are uncommon in collections and, therefore, of especial scientific concern. The Museum is working with the police and the Wildlife Crime Unit on the matter.
Anyone with any information on this crime should ring DI Wylie via the non-emergency number +448453300222, citing crime reference number D3/09/450. Alternatively, call Crimestoppers (an independent charity) anonymously on +44800555111.
Read the full news at the Natural History Museum website: http://www.nhm.ac.uk/about-us/news/2009/august/tropical-bird-theft-at-natural-history-museum.html
Read the full Museum targeted in tropical bird theft press release: http://www.nhm.ac.uk/about-us/press-office/press-releases/2009/natural-history-museum-targeted-in-tropical-bird-theft.html
Research stations in Antarctica are sullying the pristine environment by improperly disposing of sewage waste, reports a study published this month in Polar Research. Twenty-eight countries have a total of total of 82 research stations in the Earth's southern-most landmass, and "they need to take action to prevent the release of microorganisms to the Antarctic environment," said Fredrik Gröndahl of the Royal Institute of Technology in Stockholm, who led the study.
"It's phenomenally expensive to do anything down there," says Gröndahl. "But if we want to preserve Antarctica as pristine as possible, we need to take [on] the costs."
Posted at The Scientist by Alla Katsnelson at 14th August 2009 03:51 PM GMT
Read the complete story at: http://www.the-scientist.com/blog/display/55889/
13 agosto 2009
"They're consuming anything from geckos to shearwater to tree lice to more juicy items that you would expect them to eat, like caterpillars. They're just like little vacuum cleaners," said Erin Wilson, who recently completed her doctorate at UC San Diego and is the lead author of the study reported in the Proceedings of the National Academy of Sciences this week.
The sheer numbers are changing the ecology of Hawaii's endangered ohia woodlands and subalpine shrublands. "It's not just what they're killing," Wilson said. "They're also collecting great amounts of nectar, drawing down the resources for anything else that might want to feed on it whether it's native insects or birds like the Hawaiian honeycreepers."
Read full news at: http://www.sciencedaily.com/releases/2009/07/090720190609.htm