> Imagine if we had the unambiguous source code for our own bodies?
We sequenced human DNA, so I think we already have something kinda like it. I'm not a scientist but my basic understanding is that while we have the whole sequence (in your source code analogy, we can do git clone or git pull) we are not really good at tweaking it ("oops this codebase uses architectural solutions we're not familiar with, we will have to study it extensively before we can deploy those proposed changes to the production environment")
DNA is not really source code. At best, it's kind of like... an algorithm textbook. Only a very tiny portion of DNA (like, ~1-2% in Homo sapiens) codes for proteins in the manner that you would have learned in biology class. A much larger fraction is used somehow, but how much and what its functions are is still a matter of major debate.
The effort to sequence the human genome has also led us to discover that there are other ways in which traits can be heritable that don't involve changes to DNA. The focus now is largely on epigenetics, although explanations invoking microbiomes of bacteria inside our organs was definitely popular for a while.
In short, we really don't know a whole lot about our own molecular biology, and a lot of the research in the past 60 years since the discovery of DNA has tended to show "there's more going on than we thought." Where things involve just DNA, we have very good tools for reading (sequencing) and writing (CRISPR/Cas9) it. What we don't have good tools for is modifying our epigenetics, and we don't have a good handle on what comes from DNA and what comes from epigenetics.
Unfortunately, I'm no expert in molecular biology. Some of the more recent stuff I've picked up by following Derek Lowe's blog (http://blogs.sciencemag.org/pipeline/), which occasionally discusses some new results in molecular biology.
The standard way to learn this stuff is a course/textbook followed by reading the important papers. I recommend https://ocw.mit.edu/courses/biology/7-28-molecular-biology-s...: it is well-organized and a great use of time, even though it doesn't get into the latest most exciting topics.
If you just want an overview of what's going on, I curated these links for you. For each, focus on the main idea and why it is significant for accomplishing biological goals.
We sequenced human DNA, so I think we already have something kinda like it. I'm not a scientist but my basic understanding is that while we have the whole sequence (in your source code analogy, we can do git clone or git pull) we are not really good at tweaking it ("oops this codebase uses architectural solutions we're not familiar with, we will have to study it extensively before we can deploy those proposed changes to the production environment")