Department of Physics, Chemistry and Biology (IFM)

Comparative studies are important in order to understand the evolution of the sense of taste. One factor that has an impact on the evolution of this sense is the dietary specialization of a species, which appears to be linked with the species’ taste perception.

The primate order is suitable for comparitive studies of taste perception. It is an interesting order to study, not only because we humans belong to it, but also because of the great diversity in the feeding ecology that is present. The dietary specializations of different primate species include, for example, frugivores, insectivores, gummivores, omnivores and folivores. Some species have a more specialized diet than others, with the black-and-white ruffed lemur (Varecia variegata) being highly frugivorous. Indeed, up to 92 % of their diet in the wild consists of fruits.

Taste perception in animals has been assessed both behaviourally, using the two-bottle preference test (TBP), and physiologically by assessing, for example, taste receptors and/or nerve activity. The taste preference threshold is assessed by studying the behaviour of the animal, whereas the detection threshold is usually found by physiological experiments. 

Several studies have already tested whether or not different mammalian species, including primates, can perceive, and have a preference for, a variety of different substances. Humans perceive several different substances as sweet tasting (e.g. polyols, saccharides, amino acids). The taste preference and sensitivity of the black-and-white ruffed lemur for different substances is not well documented. So far it has only been studied for simple sugars, e.g. glucose and fructose, and some amino acids and sweeteners.