Monday, 12 November 2018

Anolis dracula: A new, cryptic, species of Anole from Colombia and Ecuador.

Anoles are small Iguanid Lizards found in the Southern United States, Mexico, Central America, the Caribbean, and South America as far south as Paraguay. They are excellent climbers, with adhesive pads on their feet similar to those seen in Geckos., but unlike Geckos are typically active during the day, when they are active predators of Insects and smaller Vertebrates, though some species will also eat fruit, flowers and nectar. Many species of Anole can change their colour to blend in with their background, and all can shed their tails to escape predators. Anoles are highly territorial, with both males and females having territories, though those of the males are larger and typically overlap with those of several females. Most Anoles have a large dewlap (a throat flap erected by a piece of cartilage in the neck), which tends to be brightly coloured and patterned both at (Human) visible wavelengths and in the near ultra-violet. The genus Anolis is the largest genus of terrestrial Vertebrates, with over 425 species, though most of this diversity is found in the Caribbean, where the Lizards have undergone multiple adaptive radiations. Each Island has its own set of Lizards, which tend to be most closely related to other Lizards on the same island, but a series of similar morphotypes, each adapted to a different ecological role, has appeared repeatedly on different islands.

In a paper published in the journal ZooKeys on 1 November 2018, Mario Yánez-Muñoz of the Unidad de Investigación at the Instituto Nacional de Biodiversidad, Carolina Reyes-Puig, also of the Unidad de Investigación at the Instituto Nacional de Biodiversidad, and of the Instituto de Zoología Terrestre and Museo de Zoología at the Universidad San Francisco de Quito, Juan Pablo Reyes-Puig, again of the Unidad de Investigación at the Instituto Nacional de Biodiversidad, and of the Fundación Red de Protección de Bosques and the Fundación Oscar Efrén Reyes, Julián Velasco of the Museo de Zoología ‘Alfonso L. Herrera’ at the Universidad Nacional Autónoma de México, and Fernando Ayala-Varela and Omar Torres-Carvajal of the Museo de Zoología at the Pontificia Universidad Católica del Ecuador, describe a new cryptic species of Anolis from southwestern Colombia and northwestern Ecuador.

Cryptic species are species that closely resemble other species, and cannot be separated by simple, non-invasive examination. While taxonomists have known about cryptic species for a long time, it was not realised how numerous such species were until taxonomists began to use genetics to determine relationships between species, about twenty years ago. The presence of cryptic species can have a profound influence on conservation efforts, as ‘species’ thought to be wide ranging with large populations and broad environmental tolerances can turn out to be complexes of closely related but reproductively isolated species, each with a smaller population and distribution, and narrower range of environmental tolerances.

The new species is named Anolis dracula, in reference to the Dracula Reserve in Carchi Province, Ecuador, which lies at the heart of the species range; the reserve in turn takes its name from the Dracula Orchids which it was set up to protect (some, but not all, Dracula Orchids are blood red). The species is found in Carchi and Imbabura provinces in Ecuador, and in Nariño Department, Colombia, with a total range of about 1582 km² in evergreen low montane forest at altitudes of between 1187 and 2353 m above sea level. The species appears tolerant of disturbance, and as well as being found in mature forests was found in secondary forest (forest in the process of regrowing after disturbance), pasture, and along the edge of roads. Anolis dracula is a large Anole Lizard distinguishable from closely related species in the same area only by genetic analysis, examination of the skull or examination of the male’s penis. The males tend to be dark brown with black, light brown and green bands, while the females are green with pink, turquoise or cream bands, but all can change colour to better blend in with their background or express their emotional state.

Colour variation in Anolis dracula. From top to bottom: Male, male, female, subadult male. Mario Yánez-Muñoz in Yánez-Muñoz et al (2018).

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Sunday, 11 November 2018

Asteroid 2002 VE68 passes the Earth.

Asteroid 2002 VE68 passed by the Earth at a distance of about 5 631 000 km (14.6 times the average distance between the Earth and the Moon, or 3.76% of the distance between the Earth and the Sun), slightly before 9.45 pm GMT on Sunday 4 November 2018. There was no danger of the asteroid hitting us, though were it to do so it would have presented a significant threat. 2002 VE68 has an estimated equivalent diameter of 150-470 m (i.e. it is estimated that a spherical object with the same volume would be 150-470 m in diameter), and an object of this size would be predicted to be capable of passing through the Earth's atmosphere relatively intact, impacting the ground directly with an explosion that would be 9350-235 000 times as powerful as the Hiroshima bomb. Such an impact would result in an impact crater 2-8 km in diameter and devastation on a global scale, as well as climatic effects that would last decades or even centuries.

Image of 2002 VE68 taken on 7 November 2010. Asteroid is the elongate object at the centre of the picture, which moved during the course of the 120 Second exposure. Martin Mobberley/Wikipedia.

2002 VE68 was discovered on 11 November 2002 by the Lowell Observatory in Flagstaff, Arizona. The designation 2002 VE68 implies that it was the 1705th asteroid (asteroid E68) discovered in the first half of November 2002 (period 2002 V).

2002 VE68 has a 225 day orbital period, with an elliptical orbit tilted at an angle of 9.01° to the plain of the Solar System which takes in to 0.43 AU from the Sun (43% of the distance at which the Earth orbits the Sun, and slightly more than the distance at which Mercury orbits the Sun) and out to 1.02 AU (2% further away from the Sun than the Earth). This means that close encounters between the asteroid and Earth are fairly common, with the last thought to have happened in November 2015 and the next predicted in October 2021. Although it does cross the Earth's orbit and is briefly further from the Sun on each cycle, 2002 VE68 spends most of its time closer to the Sun than we are, and is therefore classified as an Aten Group Asteroid. This also means that the asteroid has occasional close encounters with the planet Mercury, with the last calculated to have occurred in May 2017, and the next predicted for November 2022. As an asteroid possibly larger than 150 m in diameter that occasionally comes within 0.05 AU of the Earth, 2018 MG7 is also classified as a Potentially Hazardous Asteroid.

The calculated orbit of 2002 VE68. Minor Planet Center.

2002 VE68 is also a quasi-satellite of Venus, also circling Venus on a retrograde path on each orbit of the Sun, passing through the L4 and L5 Lagrangian points (60% ahead and behind Venus on the same orbital path) as well as in as far as the orbit of Mercury and out as far as the orbit of Earth. It is believed to have been on this orbital path for about 7000 years, having been knocked onto it by a close encounter with the Earth.

The motion of 2002 VE68 for the next 150 yr. The coordinate system rotates with Venus. Orbits of Mercury, Venus and Earth are also (schematically) illustrated. Mikkola et al. (2004).

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Saturday, 10 November 2018

Humpback Whale washes up on Californian beach.

The Channel Islands Cetacean Research Unit has reported the finding of a dead Humpback Whale, Megaptera novaeangliae, on a beach in the Ocean Dunes State Vehicular Recreation Area, to the south of San Francisco, on Friday 9 November 2018. The animal, which is thought to have been a subadult, is between 10 and 12 m in length, and appears to have been dead for several days before washing up on the beach. The cause of death is unclear at the current time, though the organisation intends to take samples from the carcass to determine this before the Whale is buried by California State Parks.

Dead Humpback Whale, Megaptera novaeangliae, on a beach in the Ocean Dunes State Vehicular Recreation Area, on Friday 9 November 2018. Chanel Islands Cetacean Research Unit.

Humpback Whales were nearly exterminated by commercial Whaling in the first part of the twentieth century. The species has been protected since 1946, and in recent years their population has appeared to be recovering in many areas, now being seen as being of Least Concern  under the terms of the International Union for the Conservation of Nature's Red List of Threatened Species. The Whales appear to be doing well off the American west coast, and are regularly sited off the coast of California, which also means that Whale strandings are becoming increasingly common, as such events become more likely when there are more Whales.

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Ebola outbreak kills 198 in the Democratic Republic of Congo.

A total of 319 cases of Ebola have been reported in an outbreak in North Kivu and Ituri provinces, Democratic Republic of Congo this year, with 198 having died, according to a report released by the country's Health Ministry on Friday 9 November 2018. This makes the outbreak the worst recorded incident in the country's history, surpassing an outbreak in 1976 which infected 318 people. Political instability in the two provinces has hampered attempts to control the outbreak, with medical workers in the region facing regular attacks by armed militia groups fighting over the regions mineral resources, and facing resistance from local populations deeply suspicious of vaccination and isolation programs.

Health workers at an Ebola treatment centre at Beni in North Kivu Province, Democratic Republic of Congo. John Wessels/Getty Images.

Ebola Hemorrhagic Fever is caused by RNA Viruses of the genus Ebolavirus. It has a reputation for being the world's deadliest viral disease, at least in part due to the 1995 film Outbreak, though this is probably slightly inaccurate as about 50% of victims survive, making it less deadly than diseases such as Rabies. However it is extremely contagious, with know known cure, and has a tendency to rapidly overwhelm local health systems as health workers themselves are infected.

Ebola begins with a fever similar to that caused by Influenza or Malaria, which tends to come on rapidly two-to-three weeks after infection (during at least part of which time the patient is already infectious). This tends to be followed by extreme respiratory tract infection, headaches, confusion, rashes and tissue necrosis and heavy bleeding. Death is generally caused by multiple organ failure.

The only known treatment for Ebola is intensive rehydration, which can improve the survival prospects of patients greatly, accompanied by anticoagulants and procoagulants to mange the diseases attacks on the circulatory system, analgesia to cope with the pain of the disease and antibiotics and antimycotics to prevent secondary infection. Due to the highly contagious nature of the disease it is recommended that healthcare workers wear full-body protection to maintain a barrier between them and their patients; a daunting prospect in the tropical regions of Africa where the disease is endemic.

Ebolavirus is thought to have a non-human animal vector, since its rapid onset and high mortality rate appears to preclude a permanent residence within Human hosts. Surveys of wild animals have found Ebola infections in Rodents and Great Apes, however these were affected by the disease in a similar way to Humans, and are therefore unlikely permanent hosts. The most likely vectors are thought to be Fruit Bats or small Primates, which are endemic to the areas where the disease occurs and which are widely eaten; cooking meat probably kills the virus, but there is a distinct danger of infection while preparing carcasses.

Electron micrograph of an Ebola Virus particle. Frederick Murphy/Centers for Disease Control and Prevention/Wikimedia Commons.

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Wildfires kill at least nine in California.

Nine people have been confirmed dead in California this week and thousands more have been made homeless, as two major wildfires sweep across parts of the state. All of the confirmed deaths occurred in the town of Paradise in Butte County, which was largely destroyed by the Camp Fire, which started in the Plumas National Forest on Thursday and rapidly spread to the town, where it is reported to have destroyed about 90% of the buildings. So far five people have been found dead in vehicles in the town, three in buildings and one outside, though another 35 people are currently missing, so it is highly likely that the number of dead will climb.

Burned out vehicles near Paradise, California, after the town was destroyed by a wildfire on Friday 9 November 2018. Peter Desilva/EPA.

Elsewhere in the state the Woolsey Fire and Hill Fire have caused extensive damage to the communities of Thousand Oaks, Casabias and Malibu, though there are no reports of any casualties due to prompt evacuations of the areas affected. Around a quarter of a million people have been evacuated from their homes across the state.

A wildfire burning in Malibu, California, this week. Reuters.

The fires have a variety of causes and have been fuelled by dry winds blowing from the mountains in the northeast of the state, but are essentially due to a prolonged drought in the state, which has been experiencing dry conditions since 2011, the longest such drought in the state's recorded history. This drought has killed vegetation, including thousands of trees, across much of central California, providing dry tinder to fuel the fires, despite high rainfall that caused flooding in parts of the state in the winter of 2016-7. The draught has been made worse by the diversion of water to suit Human purposes, such as agriculture, industry and leisure, which has taken water away from other ecosystems, resulting in the build-up of dead, dry vegetation that has produced fuel for the fires.

 The extent of fires burning in California on Saturday 10 November 2018. Google/Esri/NASA/BBC.

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Eleven killed by flash flooding in Jordan.

Eleven people have died in a series of flash flood incidents across Jordan as a series of storms swept across the Middle Eastern country this week. Full details of the casualties have not yet become available, but the deaths are known to include two women and a girl who were in a vehicle swept off the road by floodwaters in Dabaa, where at least one other person died in a separate incident, and nine people have been admitted to hospitals with flooding related injuries. Another child has been confirmed dead in Madaba Province, and around 3600 tourists had to be evacuated from the ancient city of Petra when the area was hit by flooding.

Flood damage near Madaba in Jordan this week. Petra News Agency/EPA.

Like many desert areas, Jordan, while generally arid, is prone to occasional severe flooding. This stems from two causes; firstly the arid climate prevents the development of a thick soil layer which would be expected in less dry areas, so that in much of the area (non-porous) bedrock is either exposed or close to the surface, and secondly the hot climate leads to heavy evaporation from nearby seas and oceans, so that if the wind changes direction and brings water-laden air to the area, it brings a lot of precipitation with it. This combination of heavy rainfall and low ground absorbency leads to large amounts of water at the surface, typically moving downhill at some speed. Wadis, dry channels or ravines through which these sudden floods are channelled, can be particularly dangerous at these times, particularly as they often appear to resemble natural pathways or even camp sites to people unfamiliar with the climate.

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Friday, 9 November 2018

Magnitude 5.4 Earthquake in Western Australia.

Geoscience Australia recorded a Magnitude 5.4 Earthquake at a depth 0f 3 km roughly 64 to the southeast of Manjimup in southern Western Australia, slightly after 5.05 am local time on Friday 9 November 2019 (slightly after 9.05 pm on Thursday 8 November GMT). This Earthquake was felt over a wide area, but there are no reports of any damage or casualties.

The approximate location of the 16 September 2018 Western Australia Earthquake. USGS.

Despite being a long way from any active plate margins, Western Australia is quite prone to Earthquakes, particularly in a zone referred to as the South West Seismic Zone. The cause of these quakes is unclear; the area exists within an area of Archaean Shield known as the Yilgarn Block, which is thought to be between 2.94 and 2.63 billion years old, and which has no internal structures that seem to be related to the quakes.

 The South West Seismic Zone (pink). University of Western Australia.

Witness statements can help geologists to understand Earthquakes and the geological processes that cause them; if you felt this quake (or if you were in the area but did not, which is also useful information) you can report it to Geoscience Australia here.

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