How do scientists think people migrated from asia to the americas during the last ice age

The 1884 amendment added onto the chinese exclusion act included what additional stipulation? the law would apply to ethnic chinese regardless of which asian country they originated from. the law would provide newly arrived chinese immigrants with land in the oklahoma territory. the law would establish all chinese americans as permanent aliens and deny them citizenship. the law would prohibit chinese immigrants from reentering the united states once they exited.