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What’s an eyespot? Evolution of eyes – Biology

By |2017-05-28T23:15:05-07:00May 28th, 2017|Biology|

Euglena with red eyespot (thanks to Sharon Mooney) About two billion years ago, or maybe a little later, some eukaryote cells developed the ability to see. The cells that had evolved the ability to photosynthesize needed light in order to make their food. So it was important to these cells to be able [...]

Why do eyes have pupils? Evolution and Biology

By |2017-05-27T15:32:08-07:00May 27th, 2017|Biology|

By around 550 million years ago, some kinds of worms evolved eyespots sunk into their heads to protect them from being damaged. As a side effect, it turned out that being sunk into the head also helped to focus the light on just one spot, so that more light reached that spot and the worm could see [...]

How do eyes work? Evolution and Biology

By |2018-04-16T08:42:19-07:00May 27th, 2017|Biology|

A flatworm with eye-spots Living creatures have been able to tell if it's light out or not  for about two billion years. That's when some eukaryote cells evolved to be able to sense changes in their surroundings and react to them. For instance, some cells had eye spots, which could sense sunlight. When they sensed sunlight, [...]