Genesis 10-11 and Luke 3 Genealogy confusion

This is probably a boring topic to most, but I was linking Luke's genealogy to the Genesis account and doing some highlighting. My confusion is that is seems Luke adds a generation that is not mentioned in Genesis. I listed and highlighted the added Cainan in Luke but skipped in Genesis. For Scripture reference see Luke 3:35-36 and Gen. 10:22-24/11:12. I am no expert and can't figure out why Genesis says that Aphraxad's seed was passed on to his son Shelah while Luke's seems to say Aphraxad's was passed on to Cainan and Cainan's son was Shelah? Thanks in advance for the help.

Here's Luke's: 3:34-38 /Genesis Ch. 10+11
Adam /Adam
Seth /Seth
Enosh /Enosh
Cainan /Cainan
Mahalaleel /Mahalaleel
Jared /Jared
Enoch /Enoch
Methuselah /Methuselah
Lamech /Lamech
Noah /Noah
Shem /Shem
Arphaxad /Arphaxad
Cainan /..............
Shelah /Shelah
Heber /Eber
Peleg /Peleg
Reu /Reu
Serug /Serug
Nahor /Nahor
Terah /Terah
Abraham /Abraham

 

Thank you, good find. . I don't find this to be an issue at all. This argument is completely beyond my level in studies. Common sense kind of led me to come to a similar conclusion as the article. It stated:

"Although it may be appropriate to view Luke 3:36 as supplementing the Old Testament genealogies, when all of the evidence is gathered, it appears that the name Cainan in Luke 3:36 was not a part of God’s original Word, but is the result of a copyist’ s error. And as we have discussed in other articles, errors made by copyists do not represent legitimate Bible contradictions."