Wow. So I went looking if people actually knew when our codon system appeared.
Turns out that there are 26 slightly different systems on Earth right now, and there are good reasons to expect random alien life to have a system that looks like ours, but is different enough to not be compatible.
Not unless there is a common ancestor, which is theoretically possible. But yeah, extremely unlikely.
Wow. So I went looking if people actually knew when our codon system appeared.
Turns out that there are 26 slightly different systems on Earth right now, and there are good reasons to expect random alien life to have a system that looks like ours, but is different enough to not be compatible.