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Jan

15

2010
 
 

Viagra Sale




Rationale for hunting Antarctic minke whales doesn’t hold water


Leaky faucetA new study has cast doubt on the idea that Antarctic minke whales are more numerous than usual and should be hunted to make way for other whale species.


Some researchers have suggested that the population of Antarctic minke whales (Balaenoptera bonaerensis Viagra sale, ) shot up after hunters killed about 2 million large whales during the 20th century. Since large whales eat huge amounts of krill, Viagra from canada, the reasoning goes, their disappearance would have boosted the food supply for Antarctic minke whales. This species is now so abundant that it is holding back the recovery of other whales, age limits for viagra, some argue.


To find out if these whales really did undergo a population boom, Fuerza viagra, researchers collected 52 samples of minke whale meat from markets in Japan. By studying the animals’ DNA, they were able to get a better picture of the population’s genetic diversity, official viagra in india. That led the team to conclude that the number of Antarctic minke whales has historically been around 670, Is viagra safe for women, 000 – close to the number thought to exist today.


It’s possible that commercial whaling didn’t affect the population size because there was already plenty of krill in the ocean, the researchers write in Molecular Ecology. Alternatively, Antarctic minke whales may not draw from the same krill supply as larger whales, viagra sale. For instance, inter net viagra blog, they might eat different sizes of krill or hunt at different depths. Percription orlando viagra, – Roberta Kwok

Source: Ruegg, K., Anderson, fl law on ordering viagra on line, E., Where can i get viagra for sale in phila, Baker, C., Vant, what is better than viagra, M., Viagra online buy, Jackson, J., & Palumbi, pfizer viagra logo both sides, S. Free viagra without prescription, (2010). Are Antarctic minke whales unusually abundant because of 20th century whaling. Molecular Ecology, los angeles cheapest viagra, 19 (2), Bradford viagra, 281-291 DOI: 10.1111/j.1365-294X.2009.04447.x

Image © NickyBlade, iStockPhoto.com

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May

24

2008
 
 

From cradle to grave



Tree pathogen brought to the US by keen gardeners, genetic study shows

dead treesSudden Oak Death, a straightforwardly named disease caused by the fungus Phytopthora ramorum, is gaining a worrying foothold in Pacific coastal forests. A study published recently in Molecular Ecology has traced the genetic origins of the pathogen in samples from dying trees at 14 Californian forests, together with samples taken from infected nursery plants in 12 states across the US. Leading an international team, Matteo Garbellotto, a University of California, Berkeley forestry pathlogist, has uncovered genetic evidence suggesting the fungus escaped into nearby forests from plant nurseries, where it affects many common species. If that's not SOD's law, nothing is. Source: Mascheretti S, Croucher PJP, Vettraino A, Prospero S & Garbelotto M (2008) Reconstruction of the Sudden Oak Death epidemic in California through microsatellite analysis of the pathogen Phytophthora ramorum. Molecular Ecology DOI: 10.1111/j.1365-294X.2008.03773.x

Image: © Ilbusca

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Nov

26

2007
 
 

There and back again



Hybridization destroys and creates species: it depends on the environment While he coyote, he not wolf. Right?Young species often occur together, separated by a barrier to gene flow that, according to a study published recently in Molecular Ecology, is all too easily broken down. The result? Hybridization -- a frequent driver in the formation of new species -- can act to meld them together into one. The study, led by University of Bern ecologists Ole Seehausen and Gaku Takimoto, presents a string of real world examples -- the genetic tussle between coyotes Canis latrans and grey wolves C. lupus being a particularly striking one. Next, a computer model shows how hybridiziation interacts with environmental variation to generate, or erode, biodiversity. Collapsing species groups into hybrid swarms doesn’t necessarily mean a loss of genetic diversity but it plays havoc with conservation action plans. Once species have been doing their own thing for a while, though, they become resistant to such rapid demise. The first two to five million years are the worst, apparently. Source: Seehausen O, Takimoto G, Roy D & Jokela J (2007) Speciation reversal and biodiversity dynamics with hybridization in changing environments. Molecular Ecology DOI: 10.1111/j.1365-294X.2007.035293.x Image © Paul Moore

Filed Under Climate change, Endangered species, Habitat, Invasive species, Restoration | 1 Comment

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Oct

4

2007
 
 

Evolution in the fast stream



High speed adaptation could be the key to successful invasion A new look at biological invasionsRevved-up evolution allows invasive species to rampage through new habitat, a study published in Molecular Ecology shows. The seeming ease with which chinook salmon Oncorhynchus tshawytscha colonized New Zealand in the early part of the twentieth century was a complex combination of ecology and evolution, according to University of Maine biologist Michael Kinnison and colleagues. Studies of biological invasions have often considered ecology -- freedom from predators and/or parasites, lack of competition and so on -- but evolution on a short timescale has seldom been seen as a major factor. Kinnison’s neat experimental approach, which involved releasing captive-bred salmon to several NZ river systems, showed that substantial and rapid evolutionary change has taken place among populations with differing local ecological conditions. The ever-worsening threat that invasive species pose to global biodiversity suggests the need to take evolvability very seriously, and these findings raise many questions about how we tackle the problem. Source: Kinnison MT, Unwin MJ & Quinn TP (2007) Eco-evolutionary vs. habitat contributions to invasion in salmon: experimental evaluation in the wild. Molecular Ecology DOI: 10.1111/j.1365-294X.2007.03495.x Related stories in Conservation magazine: Aliens Among Us Image © Jon Helgason

Filed Under Fresh water, Habitat, Invasive species, Marine, Monitoring | 1 Comment

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Sep

3

2007
 
 

Some fins wrong



Two decades of intensive effort to save the wrong species, DNA shocker We got the wrong fish!Genetic tools are invaluable in the quest to unravel evolution’s pathway, but they’re also uncovering conservation bloopers, as a study published in Molecular Ecology shows. Efforts to save the endangered greenback cutthroat trout Oncorhynchhus clarkii stomias – through the reintroduction of captive bred fish to cleared and restored habitats – were recently hailed a success, and the subspecies’ federal protection could soon be lifted. Not so fast, say a group of scientists led by the University of Colorado’s Jessica Metcalf. Their DNA analysis sprang a nasty surprise: many of the donor populations for the breeding program were actually the closely related Colorado cutthroat trout O. c. pleuriticus. Within it’s native range, the greenback cutthroat trout is currently at a greater risk of extinction than ever before. At least we know now... Source: Metcalf JL, Pritchard VL, Silvestri SM, Jenkins JB, Wood JS, Cowley DE, Evans RP, Shiozawa DK & Martin AP (2007) Across the great divide: genetic forensics reveals misidentification of endangered cutthroat trout populations. Molecular Ecology DOI: 10.1111/j.1365-294X.2007.03472.x Related story in Conservation magazine: Do No Harm Image © Austin Dunlap

Filed Under Endangered species, Fresh water, Habitat, Monitoring, Restoration, Tools and technology | 2 Comments

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Aug

6

2007
 
 

The wheel turns and turns



Captive-bred animals continue to evolve, but not necessarily in a useful direction hey, good lookingThe California condor Gymnogyps californianus owes its existence to captive breeding programs, and many thousands more vertebrate species will only survive in the future through similarly intensive conservation efforts. However, a study published recently in Molecular Ecology warns that Nature’s own solution to changing conditions -- evolution by means of natural selection -- could work against those valiant attempts to clutch species back from the edge. Genetic adaptation to captivity can have dire effects when animals are returned to the wild, according to Macquarie University’s Richard Frankham. The relatively easy-living conditions -- sufficient food, freedom from disease and so on -- can cause populations to gear up for maximum reproductive output. This quantity-not-quality approach perhaps works fine under the watchful eye of qualified vets, but in the big bad world it can be disastrous. Replicating natural conditions is one solution, but the removal of predators is usually pretty helpful to the breeding program. If sufficient attention is given to this problem now, we might be able to find a way around it before the flood of extinct-in-the-wild species hits the zoo gates. Source: Frankham R (2007) Genetic adaptation to captivity in species conservation programs. Molecular Ecology DOI: 10.1111/j.1365-294X.2007.03399.x Image © Ferenc Cegledi

Filed Under Economics and conservation, Endangered species, Habitat, Monitoring, Restoration, Tools and technology | 1 Comment

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Mar

4

2007
 
 

How to mix Oryx



Scimitar-horned oryxFirst genetic study of “extinct” ungulates highlights need for captive breeding care Ancient genetic diversity can still be detected in the scattered captive populations of scimitar-horned oryx Oryx dammah, and some individuals are more important than others, according to a recently published study. Once numbering in millions across North Africa, the oryx is now considered extinct in the wild, so the 6000 or so animals held in zoos and private collections are vital to the species’ future survival. But the study, led by University of Southampton biologist Arati Iyengar, sounds a warning for breeding programs: the lack of coordinated effort means that genetic diversity is in danger of being lost due to inbreeding. Iyengar’s group found three distinct lineages that need to be mixed up more than they are at present. However, the global population is ageing and genetically important individuals are dying out. It looks like the oryxes need to get hornier! Source: Iyengar A, Gilbert T, Woodfine T, Knowles JM, Diniz FM, Brenneman RA, Louis EE Jr & Maclean N (2007) Remnants of ancient genetic diversity preserved within captive groups of scimitar-horned oryx (Oryx dammah). Molecular Ecology DOI: 10.1111/j.1365-294x.2007.03291.x Image © Daniel Cooper

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Feb

19

2007
 
 

Birds, bats and barcodes



Mountain chickadee, who are you?DNA taxonomy reveals unknown North American birds, South American bats Fifteen possible new bird species and eight new bat species have been uncovered in two large-scale DNA barcoding studies. A survey of 93% of North American bird species, led by Kevin Kerr at the University of Guelph, Ontario, found the new species tucked away among the rank and file of birds -- such as the mountain chickadee Parus gambeli -- that have been studied by ornithologists for centuries. The authors of the bat study, led by another of Paul Hebert’s Guelph charges, Elizabeth Clare, found that six of Guyana’s 87 described lineages contained more than one distinct species. Together, the studies lend weight to the value of DNA barcoding, a genetic technique that relies on a single stretch of mitochondrial DNA. No doubt the often-heated debate on the usefulness of the method will continue, however: DNA taxonomy is anything but black and white! Source: Kerr KCR, Stoeckle MY, Dove CJ, Weigt LA, Francis CM & Hebert PDN (2007) Comprehensive DNA barcode coverage of North American birds. Molecular Ecology Notes DOI: 10.1111/j.1471-8286.2006.01670.x Source: Clare EL, Lim BK, Engstrom MD, Eger JL & Hebert PDN (2007) DNA barcoding of Neotropical bats: species identification and discovery within Guyana. Molecular Ecology Notes DOI: 10.1111/j.1471-8286.2006.01657.x Image © Rob Pavey

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Feb

7

2007
 
 

Frog marching



Natterjack toads need roadsNatterjack toads need better links between habitat patches A new study has shed light on the tricky question of where one population ends and another begins, an important matter when it comes to saving rare species. Using the endangered British natterjack toad Bufo calamita as their muse, University of Sussex scientists Graham Rowe and Trevor Beebee fed genetic data to three Bayesian statistical software packages, hoping to find patterns in the distribution of genotypes within the UK populations. Natterjacks are at their range limit in Britain (one of the reasons for their endangered status there), and show relatively little genetic diversity. This is partly an “echo” of the last ice age, since when the toads gradually recolonised the mainland. Migration between sites is the major problem now though, and Rowe and Beebee suggest a focus on “habitat permeability” as the best way to help the remaining strongholds of this noisy amphibian. Source: Rowe, G & Beebee, TJC (2007) Defining population boundaries: use of three Bayesian approaches with microsatellite data from British natterjack toads (Bufo calamita). Molecular Ecology DOI: 10.1111/j.1365-294X.2006.03188.x

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