origin vs line of descent

origin and line of descent both are nouns.

Word	Noun	Adjective	Verb	Adverb
origin	Yes	No	No	No
line of descent	Yes	No	No	No

As nouns, origin and line of descent are synonyms defined as:

Other synonyms of origin include ancestry, blood, blood line, bloodline, descent, line, lineage, parentage, pedigree, stemma, stock.

origin (noun)	line of descent (noun)
properties attributable to your ancestry	the hereditary derivation of an individual
the point of intersection of coordinate axes; where the values of the coordinates are all zero	the kinship relation between an individual and the individual's progenitors
an event that is a beginning; a first part or stage of subsequent events
the hereditary derivation of an individual
the place where something begins, where it springs into being
the source of something's existence or from which it derives or is derived