Where do we come from?

Some people beat around the bush and say where religion comes from without answering your question...which is a good one. Inquiring minds need to know. If UFOs really exist, then it is logical that extraterrestrials have been here..which leads to the possibility that they seeded our earth some how...bringing humankind from other planets to enjoy progress in a garden of Eden (Earth). But this doesn't really explain our relationship with Apes (being we have some common DNA). So, it is even more likely, that, these extraterrestrials came down and mixed some DNA (including themselves) with the apes of this planet (different varieties of species (now extinct) would make the different races). Those who (made us) come back from time to time to monitor and maybe admire (or cringe) at their workmanship.