"Isn't the current theory that all life on Earth has a common ancestor? Wouldn't this point put that into question" Not really. For one thing there's too much

"Isn't the current theory that all life on Earth has a common ancestor? Wouldn't this point put that into question" Not really. For one thing there's too much commonality across life in terms of things like the genetic code, i.e. what a sequence of genetic letters "means". The genetic code is arbitrary but essentially universal with minor variants. For another thing, the organisms now present can be separated from each other by as much as 8 billion years of evolution (4 billion on each branch) meaning there's no particular reason to expect some shared gene to be present everywhere. New genes arise as mutations from old ones, old genes become obsolete and get removed, etc. It's vaguely like how, if you fork a coding project, and the two projects are allowed to continue indefinitely, eventually there might be no code in common, even without a complete rewrite ever happening.