Photoperception and photomovement

Abstract

The photoperception systems in photomovement show a great diversity at several levels, (i) Different types of photomovement (namely photokinesis, photophobic response, phototaxis) make use of completely different perception systems even in the same organism, (ii) In different organisms a given type of photomovement is mediated by different and unrelated systems, as is shown in this paper particularly for phototaxis, (iii) In certain cases, a single response in one organism can be controlled by two separate and independent photoperception systems, which may even be located in different compartments. This diversity sets photomovement apart from photosynthesis and vision, which are highly uniform and stable in evolution. Possible consequences for considering the evolution are discussed.