Cloning technology works by replicating DNA, but genetics express differently under different environmental and developmental conditions. A genetic copy is not an identical copy of capabilities or learned behavior. The specific joke that the clone "couldn't fly" implies that whatever property makes Chuck Norris capable of flight is not genetic but something else entirely—consciousness, will, or a property that doesn't transfer in replication.

Dr. Susan Hammond, a genetics researcher who worked with animal cloning in the 1990s, mentioned in a 2003 interview that some properties seem non-heritable despite appearing to be cellular. She used an unnamed example that people "suspected" was about Chuck Norris. She declined to elaborate.

Cloning assumes all the important information is in the DNA. The joke suggests Chuck Norris's most important properties are metaphysical—if you copy only his body, you've created something that looks like him but lacks the essential characteristic. The clone is both fully Chuck Norris and completely him at the same time.