Cultural disavowal aside, incest and subsequent inbreeding are not great. Incestuous relationships result in children with less genetic diversity, which increases their likelihood of developing genetic diseases. Accordingly, early humans figured out what a fair number of Game of Thrones characters haven’t yet: That you should do your best not to have sex with your immediate relations.
In a study published in Science on Thursday, archeologists and geneticists reveal that early humans started to avoid inbreeding much earlier than we once thought. Genomic sequencing of four Upper Paleolithic humans who were buried together in Russia about 34,000 years ago demonstrated they were no closer than second cousins, which co-author Eske Willerslev, Ph.D. says “goes against what many would have predicted.”
This likely means that early humans took extra precautions when it came time to pick a mate, connecting with a wider network of groups beyond their small family unit in order to maintain genetic diversity. The scientists believe that these hunter-gatherer bands must have developed a purposeful system for mate selection — otherwise, they would see more evidence of inbreeding.
The same cannot be said for Neanderthals, who seemed to think incest was just fine, according to research on 50,000-year-old specimens. While scientists don’t know exactly why they did so, they cautiously theorize that Homo sapiens survived as a species while the Neanderthals did not because we largely avoided inbreeding.
But early humans may have had another trick that gave them a leg up over Neanderthals: romance. Or, at least, some semblance of romance. These four humans were found in a burial site together, which is rare, and the site also contained what seems to be purposefully chosen objects and jewelry.
These artifacts, say the study authors, suggest that there were developed rules and rituals that accompanied the exchange of mates between groups — ceremonies that could have foreshadowed the invention of modern marriage services.
If you liked this article, check out this video about incest on Game of Thrones.