Since evolutionists claim that common descent is a fact, demand that it is taught as fact, and are now even demanding that the word 'theory' be tossed out, the burden of proof is on you.
Occam's Razor: "All things being equal, the simplest solution is the best".
Do you think it's simpler to have NO limit to how much an organism can change and adapt, or is it simpler to have RULES (none of which have been demonstrated or observed) that limit an organism's ability to adapt to an environment, based on some definition of a Biblical "kind"?
Can you show me the reference to the word "theory" being argued to be "tossed out" with reference to evolution? I'm not familiar with this, and I'm skeptical of your reason for bringing that up. Theories are more powerful than facts - you're aware of the scientific definition of a theory, right?
Additionally, how is one supposed to prove the ABSENCE of something? Shall I bring up the Celestial Teapot argument?
Unless you can give me A PAPER or A SINGLE REFERENCE to these "limits" you speak of, one HAS to assume there are none, you should concede your argument, and that now you're just simply grasping at straws and trying to set up strawmen.
Please site exactly what sentence(s) that the article proves common descent is true (by using empirical evidence).
The article doesn't attempt to PROVE common descent. It ASSUMES it, based on previous research by others in the field.
If you're looking for PROOF of common descent, you won't find it - science is not in the business of PROVING things. That's mathematics. If you're looking for VERY good arguments, LOTS of evidence that points toward common descent and very good SIMPLE explanations based on observations and PREDICTIONS that become evident and are found to be true time and time again, then simply read the scientific papers that are in the field. Start with Origin of Species.