What is circadian biology?

Have you ever wondered why you go to sleep when you do, get up before your alarm, get jet lag or feel more drunk when you drink alcohol at lunchtime than when you drink in the evening? Well, these are just some of the outward signs of of an internal timer called the circadian clock.

The circadian clock/circadian rhythm/body clock/circadian timing system. All terms that describe the same thing. A cellular mechanism that generates 24-hour long rhythms in behaviour, physiology, biochemistry, psychology. This collection of posts explains the what, why and how of circadian biology, with a particular emphasis on the molecular mechanism, how the circadian clock evolved and why it is useful.

My PhD investigated circadian rhythms in an unusual animal to find out more about the evolution of the circadian clock. Why study this weird creature and what can it tell us about circadian biology and biology as a whole? 

Another excellent blog (with plenty of tutorials) is @BoraZ’s Blog Around the Clock at SciAm blogs, or where he previously hosted it here.