Bilanzen des Alters — oder: Was lehren uns ostfriesische Kirchenbücher über die Evolution von Großmüttern?

• Published in: Historical social research (Köln) Vol. 30; no. 3 (113); pp. 205 - 218
• Main Authors: Voland, Eckart, Beise, Jan
• Format: Journal Article
• Language: German
• Published: Center for Historical Social Research / Zentrum für Historische Sozialforschung 01-01-2005
• Subjects: Elterliche Investitionen: Grosseltern, Eltern, Enkelkinder
• ISSN: 0172-6404

In the course of human evolution something happened, but anthropologists are unable to agree on why it happened: Humans can become twice as old as their ape ancestors. In this paper, we discuss scenarios which attempt to explain the evolutionary increase in lifespan. We substantiate these theories with data from the family reconstitution study of the Krummhörn region (Ostfriesland, Germany, 1720-1874) and come to the conclusion that two social strategies, namely "kin support" and "social manipulation", could have favored the evolution of a post-generative life-span. "Kin support", which can be presented empirically in the improved survival probabilities of grandchildren, is the adaptive strategy of maternal grandmothers, whereas "social manipulation", which can be presented empirically by increased stillbirth mortality and neonatal mortality amongst grandchildren, is the preferred strategy of paternal grandmothers (= mothers-in-law). Seen from this aspect, Ostfriesland church registers supply valuable indications for an improved understanding of evolutionary trade-offs, including senescence, and thus ultimately indications which can help with the attempts to reconstruct human social evolution.