Image: Carol MacKintosh
Meet the lancelet, our distant cousin. Over 500 million years ago, a creature just like this one made a genetic "mistake", resulting in doublings of genes which triggered the evolution of humans and other animals:
The good news is that these ancient DNA doublings boosted cellular communication systems, so that our body cells are now better at integrating information than even the smartest smartphones. The bad part is that communication breakdowns, traced back to the very same genome duplications of the Cambrian Period, can cause diabetes, cancer and neurological disorders.
"Organisms that reproduce sexually usually have two copies of their entire genome, one inherited from each of the two parents," co-author Carol MacKintosh explained to Discovery News. "What happened over 500 million years ago is that this process 'went wrong' in an invertebrate animal, which somehow inherited twice the usual number of genes. In a later generation, the fault recurred, doubling the number of copies of each gene once again."
MacKintosh, a professor in the College of Life Sciences at the University of Dundee, said that such duplications also happened in plant evolution. As for the progeny of the newly formed animal, they remarkably survived and thrived.
Jennifer Viegas of Discovery News has the post: Link