A pseudogene is a DNA sequence that resembles a gene but has been mutated into an inactive form over the course of evolution. A pseudogene shares an evolutionary history with a functional gene and can provide insight into their shared ancestry.
Pseudogene. It's a funny word. It sounds like you almost made it into being a gene, but you didn't quite cut the mustard. And that actually is pretty close to accurate. A pseudogene is a DNA sequence that resembles a gene but has been mutated through the course of evolutionary history so it's now inactivated. A pseudogene, then, shares some evolutionary history, so it shares some DNA sequence with the real gene, or the active gene. But because it's been mutated, it's generally inactive, and it really doesn't do much except sit there and provide us with information about the evolutionary history of the gene family or the organism, or that particular part of the genome under consideration.- Elaine A. Ostrander, Ph.D.