ABSTRACT

We examined the self-reported family trees of 288 adult Argentines from a mid-size city near Buenos Aires to evaluate how intergenerational transmission of ancestry information matched (or not) anonymized estimates of continental-level genetic ancestry. Intergenerational transmission of ancestry information was inferred from the content of the anonymized family trees, and continental-level ancestries were inferred from genomic information collected from the participants. We found a high degree of concordance between genetic ancestry estimates and the transmission of ancestry information in ancestors born in Europe, the Middle East, and Southeast Asia. We found the reverse in ancestors who were Indigenous American, sub-Saharan African, or their descendants. Yet, the existence of those ancestors was evident in the genetic ancestry estimates. We extrapolated the presence of such ancestries in family trees post hoc by deducing that some ancestors identified as ‘Argentine’ in family trees were likely of mixed Indigenous- and non-Indigenous-descent, and possibly also sub-Saharan African descent. We describe these findings as products of a process of attrition, in which some ancestries, but not others, have been forgotten (knowingly or unknowingly) over the course of generations, to the point that participants were unaware that ethno-racial mixing occurred within their own families.

摘要

我们检查了来自布宜诺斯艾利斯附近一个中型城市的 288 名成年阿根廷人的自我报告家谱，以评估祖先信息的代际传递如何匹配（或不匹配）大陆水平遗传祖先的匿名估计。祖先信息的代际传递是从匿名家谱的内容中推断出来的，大陆级别的祖先是从参与者收集的基因组信息中推断出来的。我们发现出生在欧洲、中东和东南亚的祖先的遗传血统估计和血统信息的传递之间高度一致。我们在美国原住民、撒哈拉以南非洲人或其后裔的祖先中发现了相反的情况。然而，这些祖先的存在在遗传血统估计中是显而易见的。我们通过推断家谱中被识别为“阿根廷”的一些祖先可能是土著和非土著后裔的混合后裔，也可能是撒哈拉以南非洲后裔，事后推断出家谱中是否存在此类祖先。我们将这些发现描述为消耗过程的产物，在这个过程中，一些祖先（而不是其他祖先）在几代人的过程中被遗忘（有意或无意），以至于参与者没有意识到种族混合发生在他们的内部。自己的家庭。