Let's say aliens are responsible for some of the break-thru technologies known to men to date. For example they taught us to; make fire, create tools and weapons, create an agricultural society, how to build a steamengine, etc. Let's assume men has learned from these examples and is now evolved enough to invent new technologies on their own (although maybe on a slower pace). Do you think humankind still needs aliens to assist in their technical progression or do you think 'we are save for the future to come' and can make it on our own (that is live on forever as a species or be destroyed by our own pollution and/or wars).