Genealogies of individual persons or of groups or families are to be found in many places in the Old Testament but are most common in Genesis, 1 Paralipomenon, and 1 and 2 Esdras.
In Genesis the genealogical lists serve a peculiar purpose; they show the relationship of the Hebrews to the other peoples, and, gradually, by eliminating the various lines whose history is not directly connected with the transmission of the Divine promises, concentrate the reader's attention on the line from which the Chosen People are sprung, so that the narrative, begun as a history of the world, finally becomes the history of the Hebrew people.
The genealogies are naturally meant to show the blood relationship of those whose names figure in the lists; however, this is far from being the purpose of the biblical genealogies in every case, or at least from being their primary purpose, for in several instances, as in the Table of Nations (Genesis 10), the writer does not seem to have intended blood relationship, but rather some political or geographical relationship.
The genealogical lists found in the Bible present many complicated problems of textual and historical criticism.
Comparison of the different lists concerning the same person or the same group of persons in different parts of the Bible, or of lists covering the same period in different sections of the Bible, reveals the incompleteness of the lists, or more or less irremediable corruptions of some of the names, a thing which could take place easily enough in Hebrew owing to the similarity of several letters in the different forms of the Hebrew alphabet.
For an example of omission of names see the genealogy of Esdras in 1 Esdras 7, and I Paralipomenon 6.
The imperfections of the lists are not sufficient reason for denying their authority.
That families preserved their genealogies carefully appears from the proof which for instance the priests were expected to give of their descent; those unable to produce satisfactory evidence were excluded (Esdras 2).
The same impression is derived from the New Testament references which take it for granted that individuals were able to trace their descent (Luke 1; 2; Philemon 3).
New Catholic Dictionary