【推荐1】A world in which extinct creatures could be brought back to life came a step closer yesterday. Australian scientists have managed to extract a gene from a preserved sample of a Tasmanian tiger and make it active. The breakthrough has left them dreaming that one day they will be able to recreate the animal, which died out more than 70 years ago. And if it can be done with the Tasmanian tiger, it may also be possible to resurrect (复活) creatures that have been extinct for far longer.

“There used to be a time when extinction meant forever, but no more, ” said Professor Mike Archer. “We are now able to seriously challenge whether those animals that have gone for ever. What has been achieved is a very important step in bringing back those animals that are extinct. And while I think that technically it is still pretty difficult at the moment, we can now see the possibilities. I’m personally convinced that the Tasmanian tiger will be brought back to life in my lifetime.”

The breakthrough came after nine years of experiments by scientists at the University of Melbourne, who extracted a gene from one of several tigers preserved in alcohol in a Melbourne museum. They removed the equivalent gene from a mouse embryo implanted the tiger gene and then watched as the mouse continued to grow normally, suggesting the tiger gene had been activated.

Team leader Dr. Andrew Pask said it was the first time DNA from an extinct species had been used to “induce (引起) a functional response in another living organism”.

However, the animal’s entire gene structure would have to be revived in the same way to even begin the possibility of bringing the Tasmanian tiger back from the dead.

Mick Mooney, a wildlife officer of the Tasmanian Government, was worried that such developments could encourage people’s indifference to the protection of endangered species.

“If people think that we can bring animals back to life after they’ve gone, they will start saying that there is nothing to worry about because we can fix it up later.”

【推荐2】I always imagined I’d be a good birder one day. But it was not to be. I finally had to acknowledge this the day I met a real birder. Toward evening, a beautiful song erupted from the woods. “Oh! What’s that one?” I asked. She looked at me with unbelieving eyes and said, “That’s still a cardinal (红雀).”

Nevertheless, after decades, I’ve gotten pretty good at the 20 or so regular bird visitors to my garden. And now I have a new ambition. I want to be able to tell individual birds apart. You know, my personal birds.

I thought my ability to distinguish our local hummingbirds (蜂鸟) would be limited to telling the females from the males, which is easy, because their feathers look different. But there’s way more going on than that. I get a good look because, like many people, I put out a nectar (花蜜) feeder. That’s mainly for my benefit, to draw them close. Hummingbirds get plenty of juice from my flowers. But they also eat insects and spiders. Some more than others.

The hummingbird that has dominated (控制) our feeder — Hannibal Nectar — is one round, spider-filled little ball. But then there’s Noodle. She visits the feeder any time she senses Hannibal isn’t looking. She always picks her place carefully so she can look out for Hannibal. She looks right, left, up, down, and only then lowers and sucks everything she can. Hannibal comes way more often and drinks less at a time, because he knows he’s the boss. But he’s also the only hummingbird I’ve seen that makes a regular habit of checking out the nectar feeder from underneath. I know what he’s doing: There might be ants.

Poor Noodle. She’ll be attacking spider webs for material for her nest one of these days, and I hope she’s real comfortable in there, because that’s one place Hannibal will not be invited. I’d love to bring her a housewarming gift. Maybe a nice spider pot pie.

【推荐1】High-resolution (高分辨率) satellite imagery has been used to map every single tree in Africa, showing a technique that could help improve the monitoring of deforestation (森林砍伐) across the world. Florian Reiner at the University of Copenhagen, Denmark, and his colleagues used images from sate lies to map canopy (树冠) across the entire African continent.

Modern sate lies usually catch tree canopies at a resolution of 30 meters — fine for measuring the size of forests, but less good at mapping individual trees. The satellite data Reiner and his colleagues used had a resolution of 3 meters, enabling the study to map all trees, including those not part of a forest.

The results suggest that 30 percent of all trees in Africa aren’t in a forest and instead are across farmland, savannah and urban areas. “Many countries in Africa lack thick forests, but have a lot of trees.” says Reiner. “These trees are extremely important to the local ecosystems, the people and the economy. By tracking every single tree, researchers can start to monitor how these trees are coping with climate change or whether they are sensitive to deforestation.” It could also improve the monitoring of reforestation efforts, which are growing in popularity as a way of removing carbon dioxide from the atmosphere.

“At a local level, being able to consistently monitor when and where trees are disappearing or reappearing can lead to more actionable insights,” says John Francis at the Alan Turing Institute in London.

“The study is a proof of concept rather than a map ready for immediate commercial use,” says Reiner. “It’s research work. It’s showing what could be done,” he says. But he is already working with colleagues to scale up the tracking approach to cover the entire global canopy: “We’re hoping that this will be seen as a way forward in monitoring tree resources.”

【推荐3】A handful of healthy soil could contain great numbers of living organisms. However, poisonous pesticides (杀虫剂) are causing harm and destruction to them, according to a recent analysis.

For the analysis, researchers looked through nearly 400 published studies including over 2,800 experiments on how pesticides affect soil organisms. They found that pesticides harmed organisms critical to maintaining healthy soils, but these harms have never been considered in the safety reviews of the EPA (Environmental Protection Agency).Poisonous pesticides are driving factors in the sharp decline of many soil organisms, such as ground beetles. They have been identified as the most significant driver of soil biodiversity loss in the last ten years.

However, that research has always been ignored. The EPA, which is responsible for pesticide supervision(监管)in the country, openly acknowledges that somewhere between 50 and 100 percent of all agriculturally applied pesticides end up on the soil. Yet, to assess pesticides’ harms to soil species, the agency just uses a single test species, the European honeybee, to estimate risk to all soil organisms. It spends its entire life above ground in artificial boxes.

Worse still, as soil health gain popularity globally, pesticide companies have jumped up to green wash and promote their products. Every major company is now advertising its role in improving soil health, such as advocating planting cover crops. As general beliefs, these practices are indeed good for soil health and, if adopted responsibly, are a great step to take. But companies know that these practices are often accompanied by increased pesticide use. Chemicals and pesticides have to be applied more frequently to kill weeds before crops are planted.

The long-term environmental cost can no longer be overlooked. Soils are some of the most complex ecosystems on Earth, containing nearly a quarter of the planet’s biodiversity. Protecting them should be a priority, not an afterthought.