The strength of the Native American affinity was the key finding.

The western Eurasian affinity, which was also present, contributed to the interpretation of MA-1 as a representative of a population ancestral to or related to populations that contributed ancestry to both modern Native Americans and modern western Eurasians.

Critically, MA-1 showed no close affinity to modern East Asian populations — the populations that had previously been the primary reference group for Native American ancestry.

This was the finding that most directly challenged the existing models.