Animals living at high latitudes have to cope with prominent seasonal changes in their environment. In summer, they are exposed to long days and short nights with pleasant temperatures that allow reproduction, whereas the short days and low temperatures in winter require special adaptations to survive such as frost resistance and reproduction arrest.
In contrast, animals living close to the equator experience very little seasonal changes allowing reproduction throughout the year.
The circadian clock in the brain is known to control daily activity-rest rhythms and to provide an internal time reference for measuring day length. We found that the daily activity-rest rhythms and the neurochemistry of the clock network in the brain differs significantly in fruit fly species living at high and low latitudes and that these differences are causally related.
In order to understand circadian clock evolution we will investigate the clock network, the daily activity patterns of further fruit fly species living at different latitudes.
To understand the role of the circadian clock in day length measurement, we will use strains of Drosophila melanogaster caught at different latitudes. Our investigations will contribute to the understanding of circadian clock evolution by investigating fruit fly species adapted for a life at different latitudes.