A miniscule optimized visual system in the Lower Cambrian

Authors

  • BRIGITTE SCHOENEMANN,

  • JIAN-NI LIU,

  • DE-GAN SHU,

  • JIAN HAN,

  • ZHI-FEI ZHANG


Brigitte Schoenemann [bschoenem@t-online.de], Institut für Paläontologie, Rheinische Friedrich-Wilhelms Universität Bonn, Nussallee 8, 53115 Bonn, Germany; Jianni Liu [eliljn@nwu.edu.cn], Jian Han [elihanj@nwu.edu.cn], and Zhifei Zhang [elizf@nwu.edu.cn or zhangelle@126.com], Early Life Institute, State Key Laboratry of Continental Dynamics, Northwest University, Xi’an 710069, China; Degan Shu [elidgshu@nwu.edu.cn], Department of Geology, Northwest University, Xi’an 710069, China and School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China

Abstract

Simultaneously with the development of animal body plans, probably before the Precambrian, there was an explosive diversification of visual systems. Competition of performance in these visual systems was a critical factor in the evolution of life systems.

Here we analyse the visual system in the lobopod Miraluolishania haikouensis (Liu et al., 2004) from the Lower Cambrian Chengjiang Lagerstätte, Kunming, China. It consists of a very small eye with a miniscule lens. A physical problem lies in the fact that due to the usual refractive conditions of such a lens, it hardly represents an improvement of the visual quality over the basal pit- or pinhole camera eyes. To develop such a lavish visual system, however, would not have been of any value, if it achieved no more than an equal level or represented even a retrograde step in evolutionary progress. We show how this system may have allowed pattern recognition even under poor light conditions. Optimization of such a tiny eye is costly but is not ‘a wasted effort’ in evolution. In M. haikouensis (Liu et al., 2004), an excellently adapted miniscule visual system has become possible.

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