Zeitgeber

When timer any external influence is referred to in chronobiology, which can act as an exogenous component to the endogenous "internal clock " of an organism so that its inner rhythms are synchronized with the environment. For plants and animals of the most effective timer light. In addition, ambient temperature, noise, social interactions, physical activity, food intake, alarm or tampering occur by drugs as a timer.

Conceptualization

The term timer was in the early 1950s by Jürgen Aschoff, one of the pioneers in the field of chronobiology, embossed and especially by his 1954 in the scientific journal "Nature sciences " published contribution timer of animal diurnal rhythm known:

" The factors are called synchronized timer. Timer for the animal 24 -hour periodicity are all coupled to the Earth's rotation periodic environmental processes continuous or discontinuous type, which are attractive effect for the animal. "

In the scientific literature, the term " timer " in Anglo-Saxon as a loan word is common.

Examples of biological timer

Light is the most common and most effective biological timer for most organisms. It syncs the "internal clock " of plants, animals and people with the actual length of day. This Circadian rhythms are set to the day - night cycle and daily rhythms formed, for example, regulate the opening of the flowers of plants or the sleep phase of animals.

The duration of the incident light - as the length of the clear day - also influences in animals also infra Diane rhythms that come as an annual rhythms, for example, migration, mating season, hibernation and hibernation expressed. In plants, in addition to the ambient temperature and the daily light for flowering, fruit ripening and leaf drop plays a significant role. Therefore, light can be used in greenhouses for influencing the timing of harvest.