What is a major scientific hurdle cited against the feasibility of alien genetic insertion?

Answer

DNA requires a complex cellular environment with enzymes and ribosomes to function

DNA relies heavily on a specific, highly complex cellular machinery, including ribosomes and enzymes, for replication and transcription. Simply inserting a segment and expecting it to function long-term without continuous external maintenance poses a significant biochemical challenge.

What is a major scientific hurdle cited against the feasibility of alien genetic insertion?
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