The evolution of early vertebrate photoreceptors

Collin, S. P., Davies, W. L., Hart, N. S. and Hunt, D. M. (2009) The evolution of early vertebrate photoreceptors. Philosophical Transactions of The Royal Society B-Biological Sciences, 364 1531: 2925-2940. doi:10.1098/rstb.2009.0099

Author Collin, S. P.
Davies, W. L.
Hart, N. S.
Hunt, D. M.
Title The evolution of early vertebrate photoreceptors
Journal name Philosophical Transactions of The Royal Society B-Biological Sciences   Check publisher's open access policy
ISSN 1471-2970
Publication date 2009-10
Year available 2009
Sub-type Critical review of research, literature review, critical commentary
DOI 10.1098/rstb.2009.0099
Open Access Status
Volume 364
Issue 1531
Start page 2925
End page 2940
Total pages 16
Place of publication United Kingdom
Publisher The Royal Society Publishing
Collection year 2010
Language eng
Subject C1
830102 Aquaculture Fin Fish (excl. Tuna)
110906 Sensory Systems
060805 Animal Neurobiology
060409 Molecular Evolution
Abstract Meeting the challenge of sampling an ancient aquatic landscape by the early vertebrates was crucial to their survival and would establish a retinal bauplan to be used by all subsequent vertebrate descendents. Image-forming eyes were under tremendous selection pressure and the ability to identify suitable prey and detect potential predators was thought to be one of the major drivers of speciation in the Early Cambrian. Based on the fossil record, we know that hagfishes, lampreys, holocephalans, elasmobranchs and lungfishes occupy critical stages in vertebrate evolution, having remained relatively unchanged over hundreds of millions of years. Now using extant representatives of these 'living fossils', we are able to piece together the evolution of vertebrate photoreception. While photoreception in hagfishes appears to be based on light detection and controlling circadian rhythms, rather than image formation, the photoreceptors of lampreys fall into five distinct classes and represent a critical stage in the dichotomy of rods and cones. At least four types of retinal cones sample the visual environment in lampreys mediating photopic (and potentially colour) vision, a sampling strategy retained by lungfishes, some modern teleosts, reptiles and birds. Trichromacy is retained in cartilaginous fishes (at least in batoids and holocephalans), where it is predicted that true scotopic (dim light) vision evolved in the common ancestor of all living gnathostomes. The capacity to discriminate colour and balance the tradeoff between resolution and sensitivity in the early vertebrates was an important driver of eye evolution, where many of the ocular features evolved were retained as vertebrates progressed on to land.
Q-Index Code C1
Q-Index Status Confirmed Code

Document type: Journal Article
Sub-type: Critical review of research, literature review, critical commentary
Collections: 2010 Higher Education Research Data Collection
School of Biomedical Sciences Publications
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Citation counts: TR Web of Science Citation Count  Cited 40 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 44 times in Scopus Article | Citations
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Created: Wed, 16 Sep 2009, 11:26:49 EST by Cameron Harris on behalf of School of Biomedical Sciences