What is the basis of your belief that David Y. ROPER (b 1778, d 01 Sep 1843) was a son of William ROPER and Keziah YATES??

Are you aware of any actual evidence in support of this ascription?

Does it really seem plausible and likely to you that David Y. ROPER (b 1778, d 01 Sep 1843) was born OUT OF WEDLOCK three years BEFORE William's marriage to Keziah on 31 August 1781?