An interesting phenomenon found in vertebrate DNA is the existence of pseudogenes, nonfunctional copies of a gene found elsewhere in the genome. Some pseudogenes appear to have originated as double-stranded DNA copies of mature mRNA inserted into the chromosome; these copies later underwent mutations to make them into pseudogenes.
a. What sequence information might provide clues that the original source of some of these pseudogenes is cDNA copied in cells from mRNA and then inserted into the genome?
b. Would this mechanism of generating pseudogenes be more likely to have operated if the pseudogene was part of a gene family clustered in one region of the genome, or if it was instead part of a gene family whose members are scattered around the genome? Explain.
