This page contains information regarding Star Trek: Picard, and thus may contain spoilers.
Relying on the prior existence of a neural network from an existing android, this technique posited that the complete code for a new android, even including memory, could be reconstituted from a single positronic neuron of the original. The approach also entailed the creation of identical twin androids as "children" of the "parent" android.
As described to retired Admiral Jean-Luc Picard by Dr. Agnes Jurati of the Daystrom Institute's Division of Advanced Synthetic Research, this approach could be used to create an android out of biological material – "out of flesh and blood" – appearing to be Human. Based on his recent encounters with Dahj Asha, Picard and Jurati speculated that Dahj was created through fractal neuronic cloning of a neuron from Data.