A gene that doesn't do anything (like most 'pseudostudents' :-). This might seem odd, and a waste of the organism
s time. However, this can be an important evolution
ary tool for the genome
. By duplicating an existing gene
, the pseudogene can mutate as much as it likes while the real copy gets on with doing all the work.
In a sense, diploid
(see below) a pseudogenome
, since at some stage they duplicated their entire genetic material. Obviously, the genes are now functional - rather than being redundant
. This is quite clear in baker's yeast
- other creatures (us, for example) have changed so much since then that we cannot survive without both copies (except for diseases that are recessive).
A duplicated gene that is an exact copy of its duplicate is essentially a "dead" gene from the point of view of information. Although it may increase the copy number of the corresponding mRNA
's - this may or may not result in more protein. Copies may be promoterless or close to telomere
s (which also down regulates transcription).