adkron / theroutelesstraveled Goto Github PK

(https://www.youtube.com/watch?v=w98zcdFAr5A) [Video form Remote Ruby Conf]

Images attributions

• Evolution

** By Punch magazine artist. ((Punch Magazine 1882) (https://commons.wikimedia.org/wiki/File%3AMan_is_But_a_Worm.jpg)) [Public domain], via Wikimedia Commons

• Evolution of the eye

** By Remember the dot at en.wikipedia [Public domain], from Wikimedia Commons

• Eyespots

** flat light sensitive group of cells ** evolved independently 40 to 65 times ** basic sense of direction and intensity of light ** No discernment

• "cup" eyespots or pit eyes

** curved like a cup or dip in the surface ** light from more than one direction can slightly distinguish light direction ** Land Planarian (Flatworm) - By Bernard DUPONT from FRANCE (Land Planarian (Bipalium sp.)) [CC BY-SA 2.0 (http://creativecommons.org/licenses/by-sa/2.0)], via Wikimedia Commons

• Jellyfish (some) - cool information

** elaborate eyes but no brain ** eyes wired directly to muscles ** Moon Jelleyfish - By Alexander Vasenin (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons

• Deep Cup eye

** smaller opening ** true imaging ** fine directional sensing ** some shape sensing ** No lens or cornea ** poor resolution ** dim ** Nautilus - by By J. Baecker (Sony 4MPix) [Public domain], via Wikimedia Commons

• Cornea

** Transparent cells cover the eye and protect it from bacteria ** fills with transparent liquid ** color filtering ** blocks ultraviolet radiation ** operates out of water ** Onychophora - By Velvet_worm.jpg: Geoff Gallice derivative work: B kimmel (Velvet_worm.jpg) [CC BY 2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons

** Blue and Green light only because that is what

• Cephalopod (Octopus)

** Nerves on back of rods and cones ** verabrates have nerves on top of rods and cones - creating a blind spot ** Octopus eye - By Peter Southwood (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons

• Mantis Shrimp - By Alexander Vasenin (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons Can see more colors than any animal known. 11 to 12 primary colors. Humans see 3. Red, Yellow, Blue

** Water is the likely reason we see limited colors ** Water only allows blue and green light through