Genetic “Mistake” 500 Million Years Ago Created Humans
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
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
"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