Interesting example, and what I can say won't satisfy your inquiry. However, at the same time, I won't stoop the level of personal insults like the first poster. If you really are looking for an answer, I'll provide you my perspective based on what came to the top of my mind. Based on your example, you're merely speculating that they "could" have a common ancestor. And after all these micro changes over millions of years we have all these new species. Plausible theory given it is literally impossible for us to "visualize" such change, and all we can do is hypothesize based on what we view as evidence. Here's where I'm sure our opinions diverge.
First of all, we've done a lot of digging and haven't been able to find anything close to that ancestor, or any transitional forms in between. I live in Central Oregon, and East of us are the John Day fossil beds. Aside from the beauty, there are layers and layers of sediment covering the span of hundreds of thousands, and even millions of years. There are similar geologic sites all over the world, and yet somehow we can never seem to unearth that transitional form. Sure, we've only been trying for some time, but even you have to have faith to believe that at some point that's going to happen in order to buy into Macro-evolution as your world-view. Also, because it takes millions of years to see change, on one has, or likely ever will, actually witness the birth of a completely new species from another. We've witnessed new breeds with similar genetic traits, but not the creation of entirely new species.
The second divergent point, based on your example, is the assumption that they because they look the same they must have a common ancestor. Sure, that is certainly a reasonable assumption to start from, but if I put the picture of my new baby girl up there (and she's beautiful by the way), I still see many of the same traits. 4 limbs, eyes, nose, mouth, teeth, joints, hair "fur", a brain, heart, etc...you get the picture. In any way do I see a resemblance that says common ancestor similar to your example? Certainly not, which is why you didn't include a human in that example. But the point being, I feel a creator who would create such beautiful and complex systems for breathing oxygen, processing electronic neuro-signals, the ability for vision, and all the other "micro" systems that compose the fascinating animals/plants/and life on this earth would also reuse those same components very similar to how a software engineer writes a piece of code to do some task and then assembles that code together to make more complex systems, and modifies the code to suit the specific needs of each application. I'm not introducing that as a theory, I'm simply pointing out that we can find different ways of thinking and approaching the same example. Before someone jumps out to say how simple the systems really are, or how imperfect or seemingly useless certain components are, let me say this first. For all man's "wisdom", and how "simple" these systems are, we've never been able to replicate them, or recreate life into anything that remotely resembles a complex biological organism (yes, I read that one scientist really feels he's close to producing a very simplified version of life in a lab just today). And, I never claimed everything was perfect. And if a body can adapt, change, mutate, then it is certainly within the realm of possibility that these systems are created with the capacity to also adapt, change, fit other organisms without the need to redesign the wheel so to speak.
Of course, you can guess that I'm not a supporter of macro evolution, but I also do not deny that we are wonderfully created beings with the ability to adapt, change, and improve within our own individual species. We've even learned how attempt to "mimic" life, but for all we've learned, we've never seen species adapt into entirely new species, we haven't been able to unlock the mystery of a common ancestor, and making that leap for me, is simply not compatible with my own world-view until sufficient evidence exists to prove otherwise, although I don't believe that evidence will ever be found.
That being said, macro evolution is a fine theory to explain one possible way of looking at evidence to try and figure out how we got here, and how we have come to exist in our current state. It just happens to be a theory I'm inclined to not view favorably. If I'm spreading such a thin array of clues out on a table trying to piece together a puzzle, it's one plausible theory I would logically derive.
Thanks :)