Quick sum up as the article is behind a paywall:
1/ The study is based on an analysis of genetic diversity to estimate the whole population size as well as contact with people foreign to the island.
2/ The population collapse seem to have appeared much later than thought. Following contacts "westerners" in the 19th century.
Nature link to the full publication:
https://www.nature.com/articles/s41586-024-07881-4
