line of descent vs origin

line of descent and origin both are nouns.

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

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

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

line of descent (noun)	origin (noun)
the hereditary derivation of an individual	properties attributable to your ancestry
the kinship relation between an individual and the individual's progenitors	the point of intersection of coordinate axes; where the values of the coordinates are all zero
	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