Uncommon Descent Serving The Intelligent Design Community

If neurons evolved more than once on Earth…

arroba Email

From New Scientist:

Until recently, the consensus has leaned towards a very Darwinian story. In this scenario, sometime around 600 million years ago, the common ancestor to all animals gave rise to some organisms with simple neural networks. Central nervous systems arose later, allowing for greater coordination and more complex behaviours. These perhaps started out as tight balls of neurons, but eventually gave rise to the magnificently complex primate brain.

The story was somewhat turned on its head by the recent whole genome sequence of comb jellies. These small marine animals look like jellyfish but in fact seem to be only distantly related. They use a neural network just beneath their skin and a brain-like knot of neurons at one end to catch food, respond to light, sense gravity and escape predators.

When the first full genome of the comb jellyfish was published in December 2013, it suggested they had branched off from the animal family tree earlier than jellyfish, and before the brainless sponges. If comb jellies came first and sponges came later, says Leonid Moroz of the University of Florida at Gainsville, then either sponges lost their neurons or neurons were invented twice. More.

Either, as New Scientist puts it:

… the question relates to how special we are. If neurons evolved several times on our planet, then it becomes more likely that they could evolve elsewhere in the universe.

For which we have no evidence.


Design rules, and reality is information-based, not matter-based. There is a lot of evidence for that now.

In any event, if even New Scientist thinks that a “very Darwinian story” can be “somewhat turned on its head” by anything at all, times they are a-changin’.

Like we said earlier, Keep talkin’, Darwin, keep talkin’ …

See also: Genome map shows comb jellies had separate course of evolution from other animals

Follow UD News at Twitter!


Leave a Reply