【推荐2】Scientists in New Zealand are developing drones (无人机) and small radars to follow insects to try to protect threatened species. The new technology involves attaching radars to the insects to follow their movements. The devices connect electronically to drones that will track the insects in real—time. The scientists are with the University of Canterbury on New Zealand’s South Island. The team says it hopes the technology will lead to a deeper understanding of the country’s troubled insect populations.

The research builds on years of experience in the area of bird conservation, in which radio tracking methods have helped to protect many threatened species. But that technology had to be made much smaller for use on insects. The researchers have now made about 20 small “harmonic” devices that can be attached to insects. The insects can then be tracked over wide areas by drones.

Steve Pawson, from the university’s College of Engineering, said that bird-tracking technology is what made the researchers start looking for a similar solution to follow insects.

The information from tagged birds, Pawson said, “really informs conservation management.” The same system can help scientists learn more about many different insect behaviors, he added, like how far they move, where they look for food, and even, how long they live.

“If we have that knowledge, then we can incorporate (包含) it into our decision making and our planning for conservation management operations,” Pawson added.

The researchers plan to begin tests of the system on ground-based insects before moving to the greater complexities of tracking insects in flight. They hope to begin field testing by 2023.The team says the research could possibly be useful in other scientific fields as well, such as biosecurity or medical imaging.

【推荐3】Some of our planet’s power pollinators (传粉昆虫) may have originated tens of millions of years earlier than scientists once believed. In a study published July 27 in the journal Current Biology, a team of researchers traced bee family back over 120 million years to the ancient supercontinent Gondwana (冈瓦纳大陆). While looking deeper into bee history, the team found evidence that bees originated earlier, diversified faster, and spread wider than previously suspected, putting together pieces of a puzzle on the origin of these pollinators.

In the study, an international team of scientists would be in sequence and compared genes from over 200 bee species. They then compared these bees with the traits from 185 different bee fossils and extinct fossils to develop an evolutionary history and genealogical model for how bees have historically been spread around the world. The team was able to analyze hundreds of thousands of genes at a time to make sure that the relationships they inferred were correct.

“This is the first time we have broad genome-scale data for all seven bee families,” study co-author and Washington State University entomologist Elizabeth Murray confidently said in a statement. Earlier studies established that the first bees potentially evolved from wasps (黄蜂), transitioning from predators up to collectors of pollen and nectar (花蜜). According to this study, bees arose in the dry regions of western Gondwana during the early Cretaceous period, between 145 million years ago to 100.5 million years ago.

“There’s been a long-time puzzle about the origin of bees,” study co-author and Washington State University entomologist Silas Bossert said in a statement. “For the first time, we have statistical evidence that bees originated on Gondwana. We now know that bees are originally southern hemisphere insects.” The team found evidence that as new continents formed, the bees moved northward. They continued to diversify and spread in parallel partnership with flowering plants called angiosperms. The bees later moved into India and Australia and all major bee families appear to have split off from one another before the beginning of the Tertiary period (65million years ago).

【推荐2】“What would the world be if there were no hunger?” It’s a question that Professor Crystal would ask her students. They found it hard to answer, she wrote later, because imagining something that isn’t part of real life—and learning how to make it real—is a rare skill. It is taught to artists and engineers, but much less often to scientists. Crystal set out to change that, and helped to create a global movement. The result—an approach known as systems thinking—is now seen as essential in meeting global challenges.

Systems thinking is crucial to achieving targets such as zero hunger and better nutrition because it requires considering the way in which food is produced, processed, delivered and consumed, and looking at how those things intersect (交叉 ) with human health, the environment, economics and society. According to systems thinking, changing the food system—or any other network—requires three things to happen. First, researchers need to identify all the players in that system; second, they must work out how they relate to each other; and third, they need to understand and quantify the impact of those relationships on each other and on those outside the system.

Take nutrition. In the latest UN report on global food security, the number of undernourished (营养不良 )people in the world has been rising, despite great advances in nutrition science. Tracking of 150 biochemicals in food has been important in revealing the relationships between calories, sugar, fat and the occurrence of common diseases. But using machine learning and artificial intelligence, some scientists propose that human diets consist of at least 26,000 biochemicals—and that the vast majority are not known. This shows that we have some way to travel before achieving the first objective of systems thinking - which,in this example, is to identify more constituent parts of the nutrition system.

A systems approach to creating change is also built on the assumption that everyone in the system has equal power. But as some researchers find, the food system is not an equal one. A good way to redress (修正 ) such power imbalance is for more universities to do what Crystal did and teach students how to think using a systems approach.

More researchers, policymakers and representatives from the food industry must learn to look beyond their direct lines of responsibility and adopt a systems approach. Crystal knew that visions alone don’t produce results, but concluded that “we’ll never produce results that we can’t envision”.

【推荐1】An Oil for Life

Maria Alcala of Madrid speaks for many Mediterranean people when she says that “a meal without olive oil would be a bore.” No one knows when the Mediterranean civilizations fell in love with olives. That occurred before recorded history. However, there is evidence that the cultivation (种植) of olive trees began in countries around the Mediterranean Sea in approximately 4000 B.C., and 2000 years after that people in the eastern Mediterranean area began to produce oil from olives. The Mediterranean still accounts for 99 percent of all world olive oil production.

From ancient times until today, the basic process of producing the oil is the same. First, whole olives are pressed hard into pieces. Then, the liquid is separated from the solids. After that, the valuable oil is separated from the water.

Many olive growers make their ancient traditions continue and still harvest the olives by hand. “We harvest in the traditional way,” says Don Celso, an olive farmer from Tuscany, Italy. “It would be less expensive to do it with machines, but it’s more a social thing. Twenty people come to help with the harvest, and we pay them in oil.”

Olive oil has had a variety of uses through its long history. In ancient times, olive oil was used as money and as medicine. It was even used during war—heated up and dropped down on attackers. It is still used in religious ceremonies. It is great for protecting the freshness of fish and cheese. There are even olive oil lamp and olive oil soaps.

One important study shows that Mediterranean people have the lowest rate of heart disease among Western nations. This is partly associated with their frequent use of olive oil. Other studies show that food cooked in olive oil is healthier, and that eating olive oil twice a day reduces women’s risk of getting breast cancer. The world is beginning to understand its benefits, and olive oil is no longer an unusual sight at dinner tables outside the Mediterranean area. The olive oil producing countries now sell large amounts of olive oil to countries in Europe, Asia, Africa, and North and South America.

Olive oil improves the lives of people everywhere. Its benefits, recently confirmed by science, were already understood in ancient times. Mediterranean people are happy to share their secret with the world.

【推荐2】Colin Chapman, the founder of Lotus Cars, was one of motor racing's most influential engineers. He summed up his concept as “Simplify, then add lightness”. A stripped-down (精简的), featherweight car might be slower on the straights than a beefy machine, he reasoned. But it would be faster everywhere else, Between 1962 and 1978, Lotus won seven F1, constructors championships. Meanwhile, as a legend in the history of F1, Colin Chapman generously funded the sport for years.

A paper published in Nature suggests that humans struggle with subtractive (减法的) thinking. In one observational study, 100 participants were asked to change a pattern on a grid of colored squares to make it symmetrical (对称的). Although that could be done equally well by adding new squares or by deleting existing ones, 78% chose the additive option. Other tasks gave similar results. In three different studies involving changing structures built from blocks, just 2-12% of the respondents chose to remove blocks. Asked to polish an essay they had written, 16% cut words while 80% added them.

Attempts to change the situation where addition is overly favored by people work up to a point. One experiment asked participants to adjust an unbalanced Lego structure. Participants could ear a dollar for fixing the problem, but each piece of Lego they added cut that reward by ten cents. Then, researchers found 41% realized that simplifying the structure by removing a single block, rather than strengthening it by adding more, was the way to maximize the payout.

According to the researchers, people's preference for addition isn't limited to assembling blocks, cooking and writing. Actually, thinking in pluses instead of minuses could well contribute to messy homes, institutional red tape and even an overburdened planet. Having established that addition does indeed seem to be more popular than subtraction, it's then necessary to figure out what gives rise to people s missing an entire class of solutions. Some suppose people may have considered subtractive options, but deliberately choose not to pursue them, or that they don't even think of them in the first place. This open question requires more new sets of experiments.

【推荐3】Puppies can be taught. So can human children, though not for the first couple of years. Now, in the hope of fighting climate change, Dr Jan Langbein, of the Fredrich-Loweffler-Institut in Germany, and his colleagues hope they can train cows to use the toilet, too.

Cow pee（尿）contains a nitrogen-rich substance that, when broken down by enzymes（酶）, is transformed into ammonia（氨）. Bacteria in the soil, in turn, transform that ammonia into nitrous oxide, a greenhouse gas. Collecting and treating cow pee before the ammonia can be produced might, therefore, seem like a good idea. But it has proved difficult in the past without limiting the cows to small areas, which is bad for their welfare.

As Dr Langbein describes in Current Biology, this confusing problem could be solved if cows could be persuaded to voluntarily relieve themselves in a toilet. He has developed a three-stage process to help cows master toilet training. The first job was to establish the toilet. Calves（小牛）were limited to a toilet and rewarded with treats after peeing in it. Next, they were given the freedom to wander around a path outside the toilet. Peeing in the toilet were rewarded; those in the path were gently punished with a spray of water. Finally, the path was extended, to allow the animals to practice self-control over a greater distance.

Of the 16 calves involved in the training process, 11 were considered successfully toilet-trained by the end of it. Their overall performance, say the researchers, was almost comparable to that of human children. The animals managed to pee in the toilet around 77% of the time.

The next step, says Dr Langbein, is to see if cattle on a working farm can be similarly trained. Whether farmers will be keen is another question. Building toilets and training animals costs time and money, after all. But when it comes to climate change, every little helps.