Interlacing of words and rhyme suggests the complex inheritance of genetics as revealed in the speakers hands
Use of villanelle shows separation yet togetherness, two repeated lines which alternate as the end line of each stanza.
Villanelle loops, mirrors a ring, links the idea of marriage in the poem.
half rhymes shows how genetics don't create a carbon copy of the parents, it creates a new being.
Use of "you" at the end hinting at a new chapter after the reflection of the ended parents marriage.
Use of imperfect iambic pentameter reflects how relationships arn't perfect.