This is a spin-off from another thread, where a fantastic hypothetical was raised by argentine soccer fan. I think the answer would be that the civilization of the European continent would've collapsed due to overpopulation and a lack of resources, and the regions of Africa and America would have remained largely dependent on substistence agriculture and hunting. Almost surely none of the technological advances of the last 200 years would have occurred. Thoughts? Was colonialism morally wrong? Was it necessary to ensure Europe's survival? Would Africa/colonized Asia/America have been better off economically and culturally without coming under European rule?