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Australia’s biggest solar retailer forced to replace non-compliant panels
Hydropower investment positions Tasmania as battery of the nation
Penguin feathers record migration route
Bristol zoo gives rare spiders a leg-up with breeding programme
More than 1,000 of the endangered species, which come from one island off Portugal, have hatched in captivity in a world first
In what is believed to be a world first, one of the rarest spiders has been bred in captivity at Bristol Zoo Gardens. More than 1,000 Desertas wolf spiderlings, classed as critically endangered, have hatched. Keepers hand-reared some from tiny eggs as they are so precious. At birth, they measure 4mm across, but they will grow to 12cm, with a 4cm body.
The species is found in a single valley on Deserta Grande, one of the Desertas islands near Madeira, Portugal. There are about 4,000 adults left in the wild and it is hoped that some of the spiderlings can be returned to their home.
Continue reading...'Gene drives' could wipe out whole populations of pests in one fell swoop
What if there was a humane, targeted way to wipe out alien pest species such as mice, rats and rabbits, by turning their own genes on themselves so they can no longer reproduce and their population collapses?
Gene drives – a technique that involves deliberately spreading a faulty gene throughout a population – promises to do exactly that.
Conservationists are understandably excited about the possibility of using gene drives to clear islands of invasive species and allow native species to flourish.
Read more: Gene drives may cause a revolution, but safeguards and public engagement are needed.
Hype surrounding the technique continues to build, despite serious biosecurity, regulatory and ethical questions surrounding this emerging technology.
Our study, published today in the journal Proceedings of the Royal Society B, suggests that under certain circumstances, genome editing could work.
The penguins on Antipodes Island currently live alongside a 200,000-strong invasive mouse population. Wikimedia Commons, CC BY Good and bad genesThe simplest way to construct a gene drive aimed at suppressing a pest population is to identify a gene that is essential for the pest species’ reproduction or embryonic development. A new DNA sequence – the gene-drive “cassette” – is then inserted into that gene to disrupt its function, creating a faulty version (or “allele”) of that gene.
Typically, faulty alleles would not spread through populations, because the evolutionary fitness of individuals carrying them is reduced, meaning they will be less likely than non-faulty alleles to be passed on to the next generation. But the newly developed CRISPR gene-editing technology can cheat natural selection by creating gene-drive sequences that are much more likely to be passed on to the next generation.
Read more: Now we can edit life itself, we need to ask how we should use such technology.
Here’s how the trick works. The gene-drive cassette contains the genetic information to make two new products: an enzyme that cuts DNA, and a molecule called a guide RNA. These products act together as a tiny pair of molecular scissors that cuts the second (normal) copy of the target gene.
To fix the cut, the cell uses the gene drive sequence as a repair template. This results in a copy of the gene drive (and therefore the faulty gene) on both chromosomes.
This process is called “homing” and, when switched on in the egg- or sperm-producing cells of an animal, it should guarantee that almost all of their offspring inherit the gene-drive sequence.
As the gene-drive sequence spreads, mating between carriers becomes more likely, producing offspring that possess two faulty alleles and are therefore sterile or fail to develop past the embryonic stage.
Will it work?Initial attempts to develop suppression drives will likely focus on invasive species with rapid life cycles that allow gene drives to spread rapidly. House mice are an obvious candidate because they have lots of offspring, they have been studied in great detail by biologists, and have colonised vast areas of the world, including islands.
In our study we developed a mathematical model to predict whether gene drives can realistically be used to eradicate invasive mice from islands.
Our results show that this strategy can work. We predict that a single introduction of just 100 mice carrying a gene drive could eradicate a population of 50,000 mice within four to five years.
But it will only work if the process of genetic homing – which acts to overcome natural selection – functions as planned.
Evolution fights backJust as European rabbits in Australia have developed resistance to the viruses introduced to control them, evolution could thwart attempts to use gene drives for biocontrol.
Experiments with non-vertebrate species show that homing can fail in some circumstances. For example, the DNA break can be repaired by an alternative mechanism that stitches the broken DNA sequence back together without copying the gene-drive template. This also destroys the DNA sequence targeted by the guide RNA, producing a “resistance allele” that can never receive the gene drive.
A recent study in mosquitos estimated that resistance alleles were formed in at least 2% of homing attempts. Our simulation experiments for mice confirm this presents a serious problem.
After accounting for low failure rates during homing, the creation and spread of resistance alleles allowed the modelled populations to rebound after an initial decline in abundance. Imperfect homing therefore threatens the ability of gene drives to eradicate or even suppress pest populations.
One potential solution to this problem is to encode multiple guide RNAs within the gene-drive cassette, each targeting a different DNA sequence. This should reduce homing failure rates by allowing “multiple shots on goal”, and avoiding the creation of resistance alleles in more cases.
To wipe out a population of 200,000 mice living on an island, we calculate that the gene-drive sequences would need to contain at least three different guide RNA sequences, to avoid the mice ultimately getting the better of our attempts to eradicate them.
From hype to realityAre gene drives a hyperdrive to pest control, or just hype? Part of the answer will come from experiments with gene drives on laboratory mice (with appropriate containment). That will help to provide crucial data to inform the debate about their possible deployment.
We also need more sophisticated computer modelling to predict the impacts on non-target populations if introduced gene drives were to spread beyond the populations targeted for management. Using simulation, it will be possible to test the performance and safety of different gene-drive strategies, including strategies that involve multiple drives operating on multiple genes.
Thomas Prowse receives funding from the ARC and NHMRC
Joshua Ross receives funding from the ARC, NHMRC and D2D CRC.
Paul Thomas receives funding from the Australian National Health and Medical Research Council.
Phill Cassey has received funding from the ARC and the Invasive Animals CRC.
Paris climate deal: US tells diplomats to dodge foreign officials' questions
Secretary of state Rex Tillerson directs staff to make clear US wants to help other countries use fossil fuels, diplomatic cable shows
US diplomats should sidestep questions from foreign governments on what it would take for the Trump administration to re-engage in the global Paris climate agreement, according to a diplomatic cable seen by Reuters.
The cable, sent by the US secretary of state, Rex Tillerson, to embassies on Friday, also said diplomats should make clear the United States wants to help other countries use fossil fuels.
Continue reading...Foxes spotted in a Foxes fan's garden
Dam it! How beavers could save Britain from flooding
Since their trial reintroduction in Devon, the animal’s engineering skills have reduced floodwater and created a paradise for local wildlife. Should we bring them back for good?
At a secret location in the rolling pasture of west Devon lies a marshy patch of farmland protected by £35,000-worth of solar-powered electric fencing. This isn’t to keep people out but to restrain the tree-chomping, river-damming residents of these three hectares. Outside the fence is a typical small valley, with a trickle of a stream, willow thickets and pasture grazed by cattle. Inside the enclosure, the tiny stream has been blocked by 13 dams, creating pools and half-metre-wide canals. These have been built by Britain’s newest wild mammal, the beaver, which uses its waterways like we do – to transport goods. And as the beavers have coppiced trees, the willow thicket has been replaced with sunny glades of wild flowers – marsh thistles, watermint, meadowsweet – which dance with dragonflies and butterflies.
“The beavers have transformed this little trickle of a stream into a remarkable, primeval wetland,” says Mark Elliott, lead beaver project officer of Devon Wildlife Trust, which released two beavers here in 2011. “This is what the landscape would have looked like before we started farming, and it’s only six years old. That’s the amazing thing.”
Continue reading...打压盗猎盗伐,别小看了旅游业的本事
当野生动植物的存亡关系到当地居民切身利益时,他们就会成为野生动植物的最佳保护者,约翰·斯坎伦写到。
随着全球游客人数不断增长,旅行者们钟情于探索地方文化和观赏野生动植物,寻求更为丰富、更新奇的个人体验,以野生动植物为基础的旅游业正在全球范围内迅速升温。而这也促使我几年前决定从法律事业的苦海中暂时抽身,申请了6个月的无薪假期,和妹妹一起背上行囊走上了南美之旅。欣赏亚马逊雨林、伊瓜苏瀑布、马丘比丘等地的自然美景,了解保护这些美景的当地人,改变了我的一生。
联合国世界旅游组织估计,全球7%的旅游与野生动植物旅游相关,并以每年3%的速度增长,而且增长率在世界遗产地等地区还要高得多。世界自然基金会的一份报告显示,全球自然遗产中有93%支持娱乐和旅游活动,91%提供就业机会。据说在伯利兹城,超过50%的人口以珊瑚礁相关的旅游和渔业为生。
Continue reading...Regulator: It’s OK to charge customers more for energy
Fund manager bankrolls 19MW solar farm in north-west Victoria
Sandpipers are already on their way south
Pulborough Brooks, West Sussex The sun is slowly dropping towards the horizon and the air is cooling. The sandpipers are still feeding, making the most of this important stopover site on their route
Ripples flow across the golden grass as the stems bend back and forth in the breeze. A pair of common blue butterflies – the male sky blue, the female rusty brown – dance over the field. It’s quiet, apart from the tinkling of parties of goldfinches flying over, and the relentless buzz of crickets and grasshoppers rising up from the ground alongside the footpath.
I follow the track around the field and into the woods, and walk uphill to the Hanger, the viewpoint that looks out over the pools and channels of the brooks. Two young grey herons battle over the fishing rights to their small pool, raising the crests on their heads, holding their wings wide and barking sharp “frarnk” calls. Finally one gives way and heaves itself into the air, flapping slowly into the distance.
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