Horseradish, onions and caffeine all activate a group of chemical receptors that can trigger a pain signal. Turns out the same receptors exist in fruitflies, mussels, corals and mule deer. Why has this receptor survived a half-billion years? Because it protects against toxic chemicals – even if they taste good in small doses!

London pioneered video surveillance in public, but it’s catching on fast. Many major cities have systems, and more are coming. What do these cameras learn? How do they interact with other sources of data? In this culture of disclosure should we even worry about privacy?

The Titanic sank in 1912, the Lusitania sank in 1915. In each case, about 32 percent of passengers survived. But women and children did much better on Titanic, which took 160 minutes to slide underwater, than on Lusitania, which went down in 18 minutes. Ditto for rich people. Why?

Neglect, stress and abuse are all more common among the poor. New studies show that these factors can cause long-term changes in learning, brains and behavior, and suggest how to prevent damage in the vulnerable years. Could treating depressed mothers promote healthy interactions with their kids?

Changes in the junctions between nerve cells determine how well a bird will learn to sing. Regular change in these junctions helps the bird remember the song of its species, which it needs to learn to reproduce that song. Study could explain why older people have such trouble learning a new language.

Climate scientists worry about feedbacks, glacial melting, sea level rise, using tax policy to slow warming, and the complexity of climate science. Is it realistic to base our economy on endless growth? What does human behavior tell us about dealing with warming?

Do new species arise because so many niches are available in a new habitat? Or do they arise because newcomers have multiple talents for survival? A new study points to traits that enable success in the new location.

Aftershocks and triggered earthquakes both follow a large earthquake, and they don’t happen at random. Can lessons about the sequence and timing of quakes improve safety?

To hide from hungry fish, this animal houses luminous bacteria. But what prevents the bacteria from reproducing and killing the squid? At last, a genetic a balancing mechanism is revealed.

The long rise may be inflated by redefinition of autism, social acceptance of the disabled and desire for services. If this is a real epidemic, it’s even more critical to find the cause.