14 DAY TRIAL // We possess an inner clock that assigns as to be either an owl or a lark. Another inner clock reacts to seasons, that's why for some the winter is a reason for joy, while for others it can mean depression.
Now a team at the University of Edinburgh is focusing on the behavior and biology of primitive sheep breed for a better knowledge of how humans are affected by the change of the seasons.
The researchers investigated a herd of 50 Soay sheep from Scotland's Fife Island, St Kilda archipelago (located about 41 mi (65 km) away from the Western Isles), which are not affected by cross-breeding with other sheep breeds. The sheep come from Soay, another island of the St Kilda group (the islands are owned by the National Trust of Scotland).
These sheep are already known to have a 10-month cycle that determines their appetite, fattening as well as moulting periods, and the researchers are aiming to detect the mechanism of the inner clocks, to see how humans are affected by winter and night shifts. The origin of this breed is still unknown: some think they were brought there by Vikings in the 9th and 10th centuries, while others believe they inhabited the British islands before the arrival of the Romans or Vikings.
"The animals' "body clocks" appeared to be a wild-type unaffected by cross breeding throughout the centuries. While our daily - or circadian - body clocks anticipate the change between day and night, our circannual clocks anticipate the seasons as we orbit the sun. As our clocks are pre-set and individual, this explains why some people are larks and others owls, and why some suffer severely in winter." said Dr Gerald Lincoln, of the university's Centre for Reproductive Biology.
By now, scientists had detected the cells responsible for the human circadian "body clock" and now they want to track down the specific genes linked to the body's long-term timing.
"By doing this, we hope to find new clinical treatments. It could be beneficial to those working night shift, who suffer poor health and have reduced life expectancy, as well as looking at how our metabolism is regulated throughout the year. The calendar genes could even provide new insight into the most basic timed mechanisms of DNA repair and aging." added Lincoln.