Timing in the Animal Realm

Fruit flies always emerge from the pupal stage early in the morning when there is high humidity. In the middle of the day, their tender wings would be at too much risk of drying out before having properly hardened. An inner clock helps them not to miss the right time of emergence.

Many flowers are not opened all day long. In order to provide themselves reliably with pollen and nectar, honey bees are able to remember up to nine times of the day so that they can virtually execute a flower visiting plan. In the afternoon, for instance, they make a beeline for flowers that are only opened in the afternoon.

Desert ants make many turns in various directions when foraging for food. When they have found a food item, however, they return to the nest in the most direct way so as to get out of the life-threatening heat as fast as possible. Without satellite navigation, they are able to “calculate” the shortest route home, just using the sun as a compass.

Timing: a largely unexplored field

These examples show: Timing is everything – not only in the everyday life of humans. All organisms follow certain time schedules. This protects them from heat, cold and other unfavorable environmental conditions, ensures access to food and generally promotes their survival. In order to keep to the schedules, animals have developed various mechanisms, some of which are little known to science. These include internal clocks as well as impressive learning and memory capabilities.

Timing in the animal realm: This largely unexplored field is now being studied by researchers of the University of Würzburg at a newly established Collaborative Research Center. They are going to analyze several timing mechanisms in solitary and social insects – at the level of nervous systems, sensory and nerve cells as well as molecules. They are also examining the relevance of the timing mechanisms in terms of development, reproduction, social behavior and adaptation to the environment. The results will enable the researchers to draw conclusions about other animals and humans as well. This is because the internal clocks haven't changed much in the course of evolution.

Looking at complex biological communities

In order to determine how timing works in animals, the Würzburg biologists also examine complex biological communities in outdoor environments, such as the system “fungus – plant – aphid – ladybug”: When aphids suck at certain grasses, the plants defend themselves by mixing bitter-tasting substances into their sap. The bitter substances come from a fungus that lives in symbiosis with the grasses.

Now, the aphid colony needs good timing: At which point does the sap become so unpalatable that switching to another host is worth the trouble? Incidentally, switching hosts is not that simple, requiring the ability to fly. However, the aphids solve the problem in an elegant way: When the sap of the grass becomes too bitter, they simply produce offspring endowed with wings. How does this happen? And how do the aphids react when – as a new threat in addition to the problem with the bitter sap – ladybugs, which are known to snack on the occasional louse, enter the game? This project will also be undertaken by the Würzburg scientists at the new Collaborative Research Center.

Information on the Collaborative Research Center

The studies are funded by the German Research Foundation (DFG). Over the coming four years, the foundation is going to invest about seven million euros in the Würzburg Collaborative Research Center “Insect timing: mechanisms, plasticity and interactions”, which will be launched on 1 January 2013. About 70 persons participate in the program; Professor Charlotte Förster is the spokesperson. She is the chair of the Department for Neurobiology and Genetics at the Biocenter of the University of Würzburg.

Collaborative Research Centers are considered flagship projects certifying the excellent research quality of the respective universities. They are subject to a strict review procedure before being approved by the DFG; there is a fierce competition for the funds. Collaborative Research Centers are granted for an initial funding period of four years. After reviewing them anew, the DFG can extend this period by another four years with a maximum funding duration of twelve years.

Departments involved

The new Collaborative Research Center primarily concerns scientists at the Biocenter of the University of Würzburg, including the Departments of Neurobiology and Genetics, Zoology II (Behavioral Physiology and Sociobiology), Zoology III (Animal Ecology and Tropical Biology), Botany I (Molecular Plant Physiology and Biophysics) and the Departments of Biochemistry and Pharmaceutical Biology.

The Department of Physiology, the Rudolf Virchow Center for Experimental Biomedicine, the Institute for Medical Radiation and Cell Research and the Brain Research Institute of the University of Zurich are also involved.
Profiles of the participating researchers (pdf)

Contact person

Prof. Dr. Charlotte Förster, Biocenter at the University of Würzburg, T +49 (0)931 31-88823, charlotte.foerster@biozentrum.uni-wuerzburg.de