What does the research suggest about the nature versus nurture debate regarding doppelgangers?

The research indicates that in the case of doppelgangers, nature plays a dominant role while nurture has a modifying effect. As stated in the transcript, 'nature is very strong, but nurture tunes up the genome a little bit.' This suggests that genetic similarities (nature) create the foundation for physical resemblances between lookalikes, while environmental factors (nurture) make subtle adjustments to how these genetic traits are expressed. This finding contributes to our understanding of how both genetics and environment interact to shape human appearance and potentially other characteristics.