In TF 1 we got the impression the only way to create TF life was the Allspark. TF 2 we got some more and some implications. *When Papa TF and Mama TF love each other... Jetfire flat out states he has parents. A mother and a father who was a wheel. An honorable wheel. Optimus Prime is a descendant of the Primes. Which could indicate TFs are born. This explains why there are female TFs. *The Twins, Arcees and Decepticon clones - Mudflap and Skids are twins, all three bike fembots are called Arcee, multiple Constructicons,Grindor looking like Blackout, a Bonecrusher. Now this could indicate more than just a birthing process but a mass production system which involve cloning. Finally *Protoform hatchlings. The Nemesis has hundreds if not thousands of them but they are slowly dying. Now if TFs has an alternate form of reproduction why need the Allspark? It all comes down to Energon. Energon that keeps TFs alive. I would liken Energon to human telemeres. As we age we have less telemeres. As we can see with Jetfire TFs can age without Energon. Without Energon Transformers can not maintain their population. Its a 0% population growth comparable to Japan.