Sorry if this is a duplicate. I never saw my original message appear on the list so I am re-sending this question. I have created a GP solver using ECJ. I would like to seed the first generation with a specific individual, and randomize the rest of the population as normal. How do I go about doing this? Do I have to create a custom class that can read in some kind of serialized or text form of the individual, then modify some class that creates the first generation? Or is there a simpler way? Since this is a GP the individuals are fairly complex (a rather large tree consisting of half a dozen node types). Thanks, Chris