From the Triangle to the Rhombus: Exploration, Systematization, and Material for a Genealogical Theory. (July 2021)

• Record Type: Journal Article
• Authors: Alfano, Vincenzo
• Is Part Of: Journal of family history. Volume 46:Number 3(2021)
• Page Start: 363
• Page End: 379
• Publication Date: 2021-07
• Subjects: ancestors -- loss of ancestors -- diamond theory -- pedigree collapse; Kinship -- Periodicals; Families -- Periodicals; 306.85
• DOI: 10.1177/0363199019893726
• Languages: English
• ISSNs: 0363-1990

Abstract

In this work, we aim to systematize the so-called diamond theory into a well-designed and explicated theory, that we will name "of rhombus". After introducing the problem of the number of ancestors, and offering a solution to the paradox the usual mathematical solution creates, I offer an equation that finds the number of ancestors lost for coalescence events. We discuss the main reasons for coalescence and its implications. We also apply this equation (to the best of our knowledge never before found in the relevant literature) to two specific cases: the point at which the number of theoretical ancestors becomes greater than the living population and the Toba catastrophe theory, which states that at some point the number of living human beings shrank to 6, 500.