Temperature tunes circadian timing in some desert mammals
Light has hogged all the attention in chronobiology research—but now, in camel, goat and mole rat experiments, temperature takes the lead.
When the desert heat rises, dehydrated dromedary camels—the one-humped variety found in North Africa and the Middle East—let their body temperature run wild: Their internal thermometer starts to fluctuate with the ambient temperature to help them retain water, one of many adaptations that equip them for life in an arid environment.
This adaptation is also serving neuroscientists who study circadian clocks, which are set by various external cues, or zeitgebers (literally, “time givers” in German). Light, long considered the most dominant zeitgeber, has received most of the field’s attention since the 1960s. But over the past decade, a growing number of studies have turned the spotlight onto yet another—temperature.
For desert camels and other animals in extreme environments, temperature might actually be a more important zeitgeber than light, says Khalid El Allali, associate professor of anatomy at the Hassan II Agronomy and Veterinary Institute in Morocco.