Our biological clocks could be around 2.5 billion years old, according to recent research, which suggests that the mechanism which controls our sleep and can cause jetlag could date back far further than we originally thought.
Scientists at the University of Cambridge have found that peroxiredoxin (PRX), or the so called ‘ grandfather clock’, is the enzyme responsible for what we have all come to know as the biological clock. According to the researchers, this gene could have been around 2.5 billion years ago, and has been found to lie in the most primitive of cellular life, such as in mice, fruit flies, a plant, a fungus, an alga, bacteria and even in archaea.
Akhilesh Reddy at the University of Cambridge found the enzyme, which is likely to have come about during the Great Oxygenation Event, which is a critical moment in earth’s history when the oxygen released by photosynthesis began to accumulate in the atmosphere. Mr Reddy believes PRX protected primitive cells from damage by surging when peaks in photosynthesis related to daylight temporarily bumped up levels of oxygen.
He told New Scientist: “Initially this was externally driven”, but the study stumbled on a discovery that suggests PRX became a primitive clock to help organisms survive. This enzyme would have been created in an age when the Earth span faster and a day only lasted 11 hours, which could help explain why we suffer from conditions such as jetlag.
Mr Ruddy added: “Organisms with this anticipatory ability would be better adapted than organisms that merely 'reacted' to things as they happened.
“It will have adapted to the lengthening of the day-night cycle over time.”
So if you get tired after a long flight and wonder why it is taking time to adjust to new surroundings, just remember that you have a 2.5 billion year old enzyme living within you that regulates your sleep.
Posted by Michael Ewing