If humans were truly at home under the light of the moon and stars, we would go in darkness happily, the midnight world as visible to us as it is to the vast number of nocturnal (夜间活动的) species on this planet. Instead, we are diurnal creatures, with eyes adapted to living in the sun’s light. This is a basic evolutionary fact, even though most of us don’t think of ourselves as diurnal beings. Yet it’s the only way to explain what we’ve done to the night: We’ve engineered it to receive us by filling it with light.

The benefits of this kind of engineering come with consequences — called light pollution — whose effects scientists are only now beginning to study. Light pollution is largely the result of bad lighting design, which allows artificial light to shine outward and upward into the sky. Ill-designed lighting washes out the darkness of night and completely changes the light levels — and light rhythms — to which many forms of life, including, ourselves, have adapted. Wherever human light spills into the natural world, some aspect or life is affected.

In most cities the sky looks as though it has been emptied of stars, leaving behind a vacant haze (霾) that mirrors our fear of the dark. We’ve grown so used to this orange haze that the original glory of an unlit night — dark enough for the planet Venus to throw shadow on Earth — is wholly beyond our experience, beyond memory almost.

We’ve lit up the night as if it were an unoccupied country, when nothing could be further from the truth. Among mammals alone, the number of nocturnal species is astonishing. Light is a powerful biological force, and on many species it acts as a magnet (磁铁). The effect is so powerful that scientists speak of songbirds and seabirds being “captured” by searchlights on land or by the light from gas flares on marine oil platforms. Migrating at night, birds tend to collide with brightly lit tall buildings.

Frogs living near brightly lit highways suffer nocturnal light levels that are as much as a million times brighter than normal, throwing nearly every aspect of their behavior out of joint, including their nighttime breeding choruses. Humans are less trapped by light pollution than the frogs. Like most other creatures, we do need darkness. Darkness is as essential to our biological welfare, to our internal clockwork, as light itself.

Living in a glare of our own making, we have cut ourselves off from our evolutionary and cultural heritage — the light of the stars and the rhythms of day and night. In a very real sense light pollution causes us to lose sight of our true place in the universe, to forget the scale of our being, which is best measured against the dimensions of a deep night with the Milky Way — the edge of our galaxy — arching overhead.

Widespread descriptions of animals in pop culture could actually be hurting the animals’ survival chances in the wild, new research suggests.

Franck Courchamp of the University of Paris-Sud was interested in the idea of “charisma”(魅力) in animals. He wanted to know: What species do people consider charismatic? And what are the influences of being charismatic on populations in the wild?

In a research published this month, Courchamp and other researchers list the top 20 charismatic species. Most of the animals identified as charismatic are large mammals living on land. Coming in first place were tigers, followed by lions, elephants, giraffes, panthers, pandas, cheetahs, polar bears, wolves, and gorillas. However, at least half of the interviewees didn’t realize that five of the top ten most charismatic species are threatened. It is paradoxical that we haven’t been able to protect the species we care about the most.

The study also found that we are flooded with images of these creatures, even as they are becoming fewer in the wild. The study suggests that too much of imagery might be creating a “virtual(虚拟的) population” of the animals in peoples’ minds, making them believe there are far more individuals in the wild than is exact.

The study authors suggest that companies who benefit from the use of these images should set aside a small percentage of their profits to protection efforts and informational campaigns (运动). “That would be not only something fair, but that would be something that could bring a win-win situation for them,” Courchamp says. It could bring them positive public relation, for example. Besides, if a company’s mascot(吉祥物) goes extinct, that could hurt them from a marketing standpoint, Courchamp says. Some companies do take this to heart, he says, noting protection efforts by Jaguar and Lacoste. But not enough companies are “truly concerned about the protection of the species that they work on,” he adds.

Living downstream from a waste-treatment plant can leave fish tired, a new study finds, led by Graham Scott, a biologist in Canada. “Wastewater treatment plants are pretty good at taking out the waste and treating it before it gets into our waterways,” he said. “But not everything can be taken out,” he added.

For example, some plants beside the stream were not designed to remove remains of drugs. So when some medicines are left over after people use them, they can be released into the environment. These include the drugs used to treat depression and high blood pressure.

Life-sustaining chemical reactions in an animal’s body (including ours) allow it to grow, move and reproduce. These reactions, taken together, are known as the creature’s metabolism (新陈代谢). Some studies have shown that even just one drug can change the metabolism of fish, making their metabolism slow down. Then that will impair their bodies.

That creates a problem for the animals — using the extra energy to rid their bodies of the pollutants which can damage their cells and tissues. “That’s energy they burn just to stay alive,” explained Scott. That is also the energy no longer available to avoid predators (天敌), to find food and to mate.

And they report that fish exposed to a mix of chemicals can use up some of their energy just to deal with those pollutants. Therefore, they will have less energy to eat and avoid being eaten, says Paul Craig, a biologist in Ontario.

“It is up to us to help reduce the types of pollutants in. wastewater,” Craig says. “That includes not throwing leftover medicines down the toilet.” he recommends.