Crystal Clear: The evolution of the eye, part 2

“I am inclined to believe that in nearly the same way as two men have sometimes independently hit on the very same invention, so natural selection, working for the good of each being and taking advantage of analogous variations, has sometimes modified in very nearly the same manner two parts in two organic beings, which owe but little of their structure in common to inheritance from the same ancestor.”

Charles Darwin, The Origin of Species

To put Darwin’s statement in other words, it looks very much as if the processes of evolution have hit upon the same solution multiple times. Continue reading

A Dentist’s Guide to the Map of Life

By Eric Kilby from Somerville, MA, USA (Clouded Leopard Mouth Open) [CC BY-SA 2.0], via Wikimedia Commons
Clouded Leopard Mouth Open By Eric Kilby from Somerville, MA, USA [CC BY-SA 2.0], via Wikimedia Commons
Imagine two people from two different tribes, separated by space or time, coming up with the same idea or way of doing something. If it is a good invention it will surely spread within each of their families and communities. Is this a coincidence, or would it make more sense if Continue reading