I'm not even talking about culture. DNA is only useful because the laws of physical reality are built a certain way. Without that context the information within DNA is meaningless.
A good analogy is perhaps a config file for a computer program.
My interpretation is that Carmack is essentially confusing a config file for the computer program itself, then saying "look how small it is, this shouldn't be that hard to reverse engineer".
To use ML terms -- Humans have "Foundation Models" which are composed of: - Their Biological makeup - The culture into which they are raised