Does Evolution Have Favourite Forms - YES!

A correspondent brought THIS ARTICLE to my notice, pointing out that Simon Conway Morris had written about the same thing in 2004 - see HERE. Very true but it does bear repeating. Evolution tends to give the same solution to similar problems even when it is starting from a greatly different source.

The main example the author uses is the crab. Apparently there are five different sorts of crabs alive in the world today. They all look rather similar but, although they are all decapods they are, otherwise, not related.

Crabs are not the only group discussed. The author mentions mammals. There are two major groups - marsupials (with pouches) and placentals which includes you and me. Very different biology but each group has a version of moles, mice, anteaters, gliders, cats and wolves.

Wolf skulls. The marsupial on the left and the placental on the right. The similarity is unmistakable.

The author goes on to discuss similar organs such as eyes. And speculates that alien intelligences may not look all that different from us. Neither the author or I think they are already among us!