Final answer:
Humans spread to disconnected continents through the Bering Land Bridge and seagoing canoes, adapting to different climates as they migrated.
Step-by-step explanation:
Humans spread to now disconnected continents through various means. During an ice age, they traveled overland on the Bering Land Bridge between eastern Russia and Alaska and migrated to the Americas. In addition, ancient humans built seagoing canoes and settled in many of the Pacific Islands. As humans developed agriculture and urban settlements, they spread throughout continents, adapting to different climates.