A study of skulls excavated from the tip of Baja California in Mexico suggests that the first Americans may not have been the ancestors of today's Amerindians, but another people who came from Southeast Asia and the southern Pacific area.

The question of who colonized the Americas, and when, has long been hotly debated. Traditionally, Native Americans are believed to have descended from northeast Asia, arriving over a land bridge between Siberia and Alaska some 12,000 years ago and then migrating across North and South America.

But recent research, including the Baja California study, indicates that the initial settlement of the continent was instead driven by Southeast Asians who occupied Australia 60,000 years ago and then expanded into the Americas about 13,500