Conventional Eye Evolution

Evolution of the Eye

https://www.youtube.com/watch?v=7jEhzAn1hDc

http://www.dailymotion.com/video/xf0ibj_richard-dawkins-explains-evolution_tech

Evolution of the Eye

Evolution of the Eye

Evolution of the Eye

Convergent Evolution

• In vertebrates, 1 represents the retina and 2 is the nerve fibers, including the optic nerve (3), whereas in the octopus eye, 1 and 2 represent the nerve fibers and retina respectively. 4 represents the blind spot, which is notably absent from the octopus eye.

Vertebrate and Cephalopod eyes

Learning from Echinoderms!

A Road Less Travelled By

Echinoderm Diversity

Starfish Crinoid Brittle Star

Sea Urchin Sea Cucumber

http://biochemicalsoul.com/2009/06/echinodermata-for-the-win/

The brittle star

http://www.ck12.org/life-science/Types-of-Echinoderms-in-Life-Science/lesson/Types-of-Echinoderms/

http://www.reef2rainforest.com/2013/08/28/brittle-stars-secrets-of-the-ophiuroidea/

The brittle star

http://www.ck12.org/life-science/Types-of-Echinoderms-in-Life-Science/lesson/Types-of-Echinoderms/

Brittle Star

Wataru Watanabe et al. J. R. Soc. Interface 2012;9:102-109

Brittle Star

Wataru Watanabe et al. J. R. Soc. Interface 2012;9:102-109

http://cronodon.com/BioTech/Ophiuroids.html

Wataru Watanabe et al. J. R. Soc. Interface 2012;9:102-109

Radial Nervous System:Look, Ma, No Brain!

Brittle Star Locomotion

https://www.youtube.com/watch?v=X8UEST-flCM https://www.youtube.com/watch?v=Xyr6_c3vdJY

Brittle Star Locomotion

Wataru Watanabe1, Takeshi Kano1, Shota Suzuki1 and Akio Ishiguro

Brittle Star Behavior

• Seek refuge in shadows, caves• Detect them from several

centimeters away, but how?

Night and Day

• Lightsensitive brittlestar species Ophiocoma wendtii changes color markedly from day (left) to night (right).

• Ophiuroid eye video! feat. Dr. Gordon Hendler

Armor and Eye in One

• Lightsensitive brittlestar species Ophiocoma wendtii changes color markedly from day (left) to night (right).

Brittle Stars Are All Eyes• Electron micrographs of calcite

skeleton reveals thousands of lenses

• Each 40 – 50 micrometers across• Each focusing on spot 10

micrometers deep => nervous system

• "Once again we find that nature foreshadowed our technical developments,"

says Roy Sambles of the University of Exeter in the United Kingdom

Brittle star eyes (Left) SEM of the cross section of an individual lens in O. wendtii.(Below)Scanning electron micrograph (SEM) of a brittlestar lens design

Brittle star eyes

Lens: composed of tiny calcite crystals.Calculated lens: what a manufactured lens would look like, performing the same function.

Nerve bundles probably pick up light signal.

Brittle Star Eyes: Biological Shades

Schematics of filtering and diaphragm action of chromatophores

Upper: night: shades of grey

Lower: day: reddish brownpigment-filled chromatophore cell; R – receptor; P – pore; L – lens

http://aizenberglab.seas.harvard.edu/papers/2005_Nanotoday.pdf

Biomimic of Brittlestar eyes

Transmission tunability through a lens array using controlled transport of light-absorbing liquid in the channels between lenses.

Images formed near the lenes focal point c)without and d) with light absorbing liquid

http://aizenberglab.seas.harvard.edu/papers/2005_Nanotoday.pdf

The cover of the journal Science features an up-close look at an artificial compound eye. The honeycomb structure is an array of mini-lenses, each of which is hooked up to a device for transmitting the incoming light signal to a central processor.

Eye Evolution “slides” click

Animals have come up with a wide variety of solutions to capturing light

But: Mantis shrimp's super colour vision debunked

What can this fish tell us?

• the first vertebrate known to have developed mirrors to focus light into its eyes.

• it technically has two eyes, each of which is split into two connected parts

Hans-Joachim Wagner , Ron H. Douglas , Tamara M. Frank , Nicholas W. Roberts , Julian C. Partridge

A Novel Vertebrate Eye Using Both Refractive and Reflective Optics

Current Biology, Volume 19, Issue 2, 2009, 108 - 114

http://dx.doi.org/10.1016/j.cub.2008.11.061

(A–C) Flash photographs of a recently captured spookfish in both dorsal (A and B) and ventral (C) view. Note the yellow-orange eyeshine in the main tubular eyes in the dorsal view and the eyeshine from the diverticulum when viewed ventrally. The black structures lateral of the main eyes in the dorsal view are the upper surfaces of the diverticula.

(D) Ventral view of both eyes removed from the head, showing the silvery argentea on the base of the main eye. The ventral edge of a “mirror” within the diverticulum (arrow) is clearly visible through a transparent ventral “cornea.”

Spookfish give us an eyeful

1. Mirror eye - light from belowa) Retinab) Mirror

2. Tubular eye – light from abovec) Lensd) Retina

The eyes of the six-eyed spookfish direct additional light to the principal eyes for improved deep-sea vision via a third pair of accessory 'eyes’, not shown.

below

above

Spookfish Eyes: Here’s Looking at you!

So, where’s the Biomimicry?