I was intrigued to learn that our body clocks, or 'biological clocks', are integral to the very cells that make up our body. PhysOrg reports:
The mechanism that controls the internal 24-hour clock of all forms of life from human cells to algae has been identified by scientists.
Not only does the research provide important insight into health-related problems linked to individuals with disrupted clocks - such as pilots and shift workers - it also indicates that the 24-hour circadian clock found in human cells is the same as that found in algae and dates back millions of years to early life on Earth.
. . .
One study, from the University of Cambridge's Institute of Metabolic Science, has for the first time identified 24-hour rhythms in red blood cells. This is significant because circadian rhythms have always been assumed to be linked to DNA and gene activity, but - unlike most of the other cells in the body - red blood cells do not have DNA.
. . .
A further study, by scientists working together at the Universities of Edinburgh and Cambridge, and the Observatoire Oceanologique in Banyuls, France, found a similar 24-hour cycle in marine algae, indicating that internal body clocks have always been important, even for ancient forms of life.
. . .
Andrew Millar of the University of Edinburgh's School of Biological Sciences, who led the study, said: "This groundbreaking research shows that body clocks are ancient mechanisms that have stayed with us through a billion years of evolution. They must be far more important and sophisticated than we previously realised. More work is needed to determine how and why these clocks developed in people - and most likely all other living things on earth - and what role they play in controlling our bodies."
There's more at the link.
I find this very interesting from the perspective of one who's experienced more than his fair share of 'jet lag'. I've always been a bit skeptical of the various techniques, tools and drugs claimed to 'reset one's body clock' and help one get over jet lag that much faster. If one's body clock is, indeed, hard-wired in the cells of one's body, it's no wonder that most of these nostrums and fads don't work very well - at least, they never have for me!