This Week: Ancient water = ancient habitat?
In the News: Texas is dry and hot. Global warming?
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!