system
Given the following post, respond as if you're commenting on Reddit:
human
How significant is the genetic difference between the Northern and the Southern White Rhino?

With the last male Northern White Rhino dying today, and only two females left, chances for survival of the northern 'half' of this species is pretty much 0. Apperently they have enough sperm to keep the two remaining ladies getting pregnant, but it is not that straight forward of course.

To my surprise however, I read that there are thousands of their Southern counterparts left. I don't have a clue about the differences between the two though. Although the reasons they are still around might be really interesting, I am more interested in the biological difference between north and south. Could 'we' rejuvinate the northern species by using their southern brethren? How different are they?
gpt
The Northern and Southern once though of as subspecies (like different breeds of domestic dogs) are believed to be of different species entirely. DNA evaluation shows it is an evolutionary divergent lineage a million or so years ago. They are similar in that they both have wide mouths as they are both grazers (where their names came from). But other than that are as different to each other as they are to the black rhino, different morphology, different genetically. Like domestic dogs are similar species to ~~wolves~~ foxes, coyotes etc NOT subspecies.

Edit: as others have pointed out, wolves and dogs ARE sub-species. But foxes and coyotes etc are not.