Forgive me for being a Doubting Thomas, but I’ve been posing the OP question to various biologists and scientists for years, and all I get from them is explanations and theories (as is evident from this thread, with one exception), which are not the same as a practical use, or even close … or, as in one case, a biologist equated his interpretation of common descent from the data with the data itself, illogically claiming that common descent was useful - but it was the data that was practically useful, not his interpretation of the data. Are you doing something similar? I don’t know.
You’re the first biologist/scientist I’ve ever encountered who claims to have empirical proof that Darwin’s tree is practically useful to science.
I’m not a YEC, btw - far from it - I accept the fossil and geological records that reveal an overall evolution of life that took billions of years. I believe in a progressive creation model, in which God took genetic material from an existing creature to create the “next” creature (this comes from the description of how God created organisms from existing matter (Genesis 2:19).
This being so, all life would be genetically linked (in a true, physical sense), so there may well be a practical scientific use for such links - only I’m not (yet) convinced there are any. It’s possible your research has indeed found a practical use for these genetic links. But my model is not based on Darwin’s tree, which is based on a contiguous process of biological evolution. My model is based on separate, but genetically-linked creations.
Incidentally, I read your article, Testing Common Ancestry: It’s All about the Mutations, which I found very interesting (although I’d be lying if I said I fully understood it!). I was wondering if the observations described in this article would be consistent with my progressive creation model.