Right. Sumer was in the southern part of what we call Iraq. it was more like a dynasty record rather than a genealogy per se, though dynasties were also usually genealogical. (You can read an article on Wikipedia if you're interested:
https://en.wikipedia.org/wiki/Sumerian_King_List). While scholars speculate whether or not the ages listed are mythological, it's of interest to me that they are generally the same spans as recorded in Genesis.
The Bible's interest in its own list is genealogical, though no genealogy in the ancient world included every generation as ours now do. Their reason for recording a genealogy were often to legitimate a king or priest. They were not primarily intended to be historical records, but in more of a political role. They are designed to give people an understanding of their identity. Such is the list in Genesis 5. The point there is to show the horror of death that sin brought upon the generations, but also to show a continuation of God's blessing despite sin.
> There is also the theory that Jesus and certain people mentioned in the Bible appear in the texts of other religions but by different names for cultural reasons.
The ancient people seem to have had multiple names, which sometimes makes it difficult for us to identify various personages. Those names were often completely different from each other. For instance, no record has ever been found of "Moses," but what we don't know is what other names he may have gone by. Eanatum of Mesopotamia was also known as Lumma. Go figure. This kind of stuff was common. Some kings had 4-5 different names, all completely different. Different from our culture, for sure.
> here is also the theory that Jesus and certain people mentioned in the Bible appear in the texts of other religions but by different names for cultural reasons.
Jesus certainly appears in other religions. Islam calls him "Isa." Hindus call hi "Ishu." Ahmadiyya Muslims call him "Yus Asaf".
Other people from the Bible appear in Babylonian, Assyrian, Greek, Persian, and Roman records, among others.