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Eye evolution and its functional basis

  • Dan-E Nilsson
Publishing year: 2013
Language: English
Pages: 5-20
Publication/Series: Visual Neuroscience
Volume: 30
Issue: 1-2
Document type: Journal article
Publisher: Cambridge University Press

Abstract english

Eye evolution is driven by the evolution of visually guided behavior. Accumulation of gradually more demanding behaviors have continuously increased the performance requirements on the photoreceptor organs. Starting with nondirectional photoreception, I argue for an evolutionary sequence continuing with directional photoreception, low-resolution vision, and finally, high-resolution vision. Calculations of the physical requirements for these four sensory tasks show that they correlate with major innovations in eye evolution and thus work as a relevant classification for a functional analysis of eye evolution. Together with existing molecular and morphological data, the functional analysis suggests that urbilateria had a simple set of rhabdomeric and ciliary receptors used for directional photoreception, and that organ duplications, positional shifts and functional shifts account for the diverse patterns of eyes and photoreceptors seen in extant animals. The analysis also suggests that directional photoreception evolved independently at least twice before the last common ancestor of bilateria and proceeded several times independently to true vision in different bilaterian and cnidarian groups. This scenario is compatible with Pax-gene expression in eye development in the different animal groups. The whole process from the first opsin to high-resolution vision took about 170 million years and was largely completed by the onset of the Cambrian, about 530 million years ago. Evolution from shadow detectors to multiple directional photoreceptors has further led to secondary cases of eye evolution in bivalves, fan worms, and chitons.


  • Zoology
  • Eye evolution
  • Photoreceptor
  • Vision
  • Visually guided behavior


  • ISSN: 0952-5238
Dan-E Nilsson
E-mail: dan-e [dot] nilsson [at] biol [dot] lu [dot] se


Functional zoology

+46 46 222 93 45

+46 70 623 10 64



Research group

Lund Vision Group


Doctoral students and postdocs

Phd Students, main supervisor


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