Evolution of the snake visual system
- Focus: Understanding what snake vision biology tells us about snake evolution, and about the evolution of the vertebrate visual system
- Funding: The Leverhulme Trust and University of Adelaide Environment Institute Small Grants Scheme
We are asking what the biology of snake vision can tell us about snake evolution and the evolution of vertebrate visual systems.
We use genetic, anatomical, physiological, and ocular media transmission data to do this.
Our team published the first visual pigment (opsin) gene sequences for snakes in 2009, and has been carrying out surveys of visual opsin genes in more than 100 snake species. These surveys cover the major ecological and taxonomic categories of snakes.
Why study snake vision?
Vertebrate vision is one of the most studied of all biological sensory systems. Its anatomical and molecular machinery and genetic underpinning are already well understood.
However, most of this knowledge is based on studies of mammals, birds and fish.
In addition, historical anatomical studies by Gordon Walls and former Museum scientist Garth Underwood demonstrated that the retinal photoreceptor cells (rods and cones) of snakes are exceptionally diverse, implying a great deal of evolutionary change.
Our work on vision in burrowing snakes links to previous work on the evolution of the caecilian visual system carried out by Mark Wilkinson and Samantha Mohun of the Museum's Herpetology Research Group.
- Prof David Hunt and Prof Julian Partridge
University of Western Australia
- Prof Nathan Hart
- Prof Ronald Douglas
City University London
- Dr Ellis Loew
- Dr Kate Sanders
University of Adelaide
- Dr Nicholas Casewell and Dr Robert Harrison
Liverpool School of Tropical Medicine
Simões B, Sampaio FL, Jared C, Antoniazzi MM, Loew ER, Bowmaker JK, Rodriguez A, Hart NS, Hunt DM, Partridge JC, Gower DJ (2015) Visual system evolution and the nature of the ancestral snake. Journal of Evolutionary Biology, 28: 1309–1320.
Mohun SM, Wilkinson M (2015) The eye of the caecilian Rhinatrema bivittatum (Amphibia: Gymnophiona: Rhinatrematidae). Acta Zoologica, 96: 147–153.
Mohun SM, Davies WL, Bowmaker JK, Pisani D, Himstedt W, Gower DJ, Hunt DM, Wilkinson M (2010) Identification and characterization of visual pigments in caecilians (Amphibia: Gymnophiona), an order of limbless vertebrates with rudimentary eyes. The Journal of Experimental Biology, 213: 3586–3592.
Davies WL, Cowing JA, Bowmaker JK, Carvalho LS, Gower DJ, Hunt DM (2009) Shedding light on serpent sight: the visual pigment of henophidian snakes. Journal of Neuroscience, 29: 7519–7525.