My memory is not the greatest there is but, someone once asked me the question “Why did you and your wife decide to have children?” What I can remember is that I thought it was a strange question at the time and I was somewhat taken aback and didn't quite know how to answer it. I assumed that basically it was just what all of us did if given a choice and if we were capable1. This is the answer I gave and I wasn't very happy with the explanation at the time. Since then I've had time to think it over but it wasn't until recently when reading an article about “the technological singularity” that I was able to formulate a much better answer.
It will essentially be a point in mankinds' existence where everything prior to that time was known and more or less followed Moore's Law2 and everything beyond that time will be unknown due to the fact that we can not know what super intelligent beings will do. 3
In my opionion, the inevitable outcome of the technological singularity will be the creation of more complex artificial beings by their predecessors. In other words, we will create intelligent artificial beings who will in turn create more advanced artificial beings and if we were to extrapolate that process there would be no end to the creation of beings so advanced they would resemble nothing we can possibly imagine (I am in no way receiving any form of retribution for recommending “The Age Of Spiritual Machines” by Ray Kurzweil but that book should be required reading for all kindergarteners. Ok, maybe second grade. If you haven't read it, go get it).8
I came to this conclusion based on the need for life as we know it today to reproduce. It would stand to reason that life, whether artificial or real and tangible4, has a need to create more life. I will take that one step further and state that life has a need to create more advanced life.