Call me perverse again and I'll call you perverse for not seeing something that denies your claim "similarities prove relationship". How about that?
By the way, the similarities (all of them except the criticism) can be attributed to all life having one designer. I do believe there is just one.
The thing is, the concept of a creator isn't needed to account for the similarities among creatures.
And while a coincidence is technically possible, anyone who argues it doesn't understand just how outrageous of a coincidence it would have to be in order for evolution to not be true.
There would have to be vasts amounts of species, all utterly unrelated to each other, coming in and out of existence just for other species to appear after them, that just HAPPENED to be a little different from the previous, only to die off and have more pop into existence that's just a little different than the last again. All this happening by chance.
It's like saying if a person doesn't have pictures of himself from every age -- say age 5, 8 and 12 -- then one could argue that all the available pictures actually consist of 3 different people.
One living to age 5, then dying off. Then another person that looks almost identical, but is a little bigger, comes into existence by chance. Then dies off at age 8. Then another comes into existance and.... well you see where I'm going with this. Just imagine this, but a much MUCH larger timescale with more total "snap shots" and more holes AND not one, but hundreds of MILLIONS of different sets of people(or species), just to show how utterly stupendous of a coincidence it would have to be. A coincidence that technically isn't disproven, but extremely unlikely.
Which brings me to a final point. In physical science, there's no two sided coin of "fact" and "false", but rather a spectrum ranging from "most probable" to "least probable". This is what most religions don't understand, is that there's no absolute certainty in the physical world even though they want to claim it. You only get that in pure mathematics as mathematical facts don't require the senses to be realized.