Evolution of the snake visual system
Understanding the evolution of vision in snakes, such as this pipe snake (Anilius scytale), could improve our knowledge of snake origins and the evolution of the vertebrate visual system © Gabriela Bittencourt Silva
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.
Most of our knowledge of vision in vertebrates is based on studies of mammals, birds fish - not snakes, like this tree boa (Corallus ) © Gabriela Bittencourt Silva
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.
To understand how snake eyes adapted to aquatic environments we have sampled sea snakes, such as Hydrophis major
Publications
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 snakeopens in a new window. Journal of Evolutionary Biology, 28: 1309–1320.
Mohun SM, Wilkinson M (2015) The eye of the caecilian Rhinatrema bivittatum (Amphibia: Gymnophiona: Rhinatrematidae)opens in a new window. 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 eyesopens in a new window. 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 snakesopens in a new window. Journal of Neuroscience, 29: 7519–7525.
Project summary
- 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
Museum staff
- Dr David Gower
- Dr Mark Wilkinson
- Dr Bruno Simões
- Filipa Sampaio
Collaborators
- Prof David Huntopens in a new window and Prof Julian Partridgeopens in a new window
University of Western Australia - Prof Nathan Hart
Macquarie University - Prof Ronald Douglasopens in a new window
City University London - Dr Ellis Loewopens in a new window
Cornell University - Dr Kate Sandersopens in a new window
University of Adelaide - Dr Nicholas Casewellopens in a new window and Dr Robert Harrisonopens in a new window
Liverpool School of Tropical Medicine
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