Second-degree relatives — grandparents and grandchildren, half-siblings, aunts and uncles with their nieces and nephews — share approximately a quarter.

Third-degree relatives share approximately one-eighth.

The further the relationship, the less genetic material is shared and the more difficult it becomes to distinguish genuine relatedness from chance genetic similarity in a population with limited diversity.

From the 64 analyzed children at the chultún, researchers identified 11 pairs of close relatives — either first-degree or second-degree relatives — based on the genetic data.

This means that among the 64 individuals, some were found to be siblings, or half-siblings, or related in other first- or second-degree ways.