I hate shopping can i buy finasteride over the counter uk “This would give two approximate 12 hour rhythms. We have shown that if we knock down the genes that code for their 24 hour clock, the animal still has very robust tidal rhythms. This shows that the 12.4 hour clock is independent from the circadian clock. I expect tidal rhythms in many coastal organisms will follow this rule including insects, crabs, even plants,” said Kyriacou.