IInversion of DNA sequences within chromosomes is a common process in evolution. The following gene arrangements in a particular chromosome are found in four different species.
1st sequence STUVWX
2nd sequence UVXTSW
3rd sequence UVWSTX
4th sequence SWVUTX
1. Assuming that the arrangement in 1 is the original arrangement, in what evolutionary order did the four species arise, such that there is only one inversion between each species. (Place 1st sequence first in your ordering.)