Unexpected Source for the Brain's Development

Reminds me  of the "Junk DNA" controversy.  Just because the purpose of something is not immediately apparent doesn't necessarily mean it is junk.  So-called "junk" may contain Hidden Treasures.

Biologists find new source for brain's development 

Milestone in the regeneration of brain cells

Glia were completely overlooked until it was discovered that Einstein's brain was packed with them... 
 

Meet Your Glia

 The Other Brain: From Dementia to Schizophrenia, How New Discoveries About the Brain Are Revolutionizing Medicine and Science