Almost all genomes have some transposable elements, i.e.: sequences that can change their place in the genome. Sometimes they can comprise the majority of the whole genome.
Doesn't this basically mean that genomes do NOT have a fixed sequence (at best single genes have it)?
How can you even sequence a genome when such things are present?
At best you can sequence a particular configuration of a genome, one among many possible ones.
Or do these elements have a "standard" or "home" location? If yes, how do you know if they are in that location or not?