There is a hierarchy of evidence here and it is more plausible to argue that two humans are related than to say an ape and a human being are related. Why because two human beings may have a human being for a child but never an ape.
That's like saying humans beget humans, but never mammals. It doesn't make sense. Humans are apes. We are mammals. Thus, we give birth to humans, apes, mammals, vertebrates, deuterostomes, etc. That's the nature of the nested hierarchy. You cannot outgrow your ancestry. It's also why we can never evolve out of being humans.
In other words there is repeatable evidence that human beings begat human beings. It is a big jump to argue that we once shared a common ancester
... with apes, I assume you mean. The point is that there is good evidence for making such a jump. Why do humans and chimps share the same retroviruses exclusive of all other animals? Common ancestry. Why does human chromosome 2 look like two fused chimp chromosomes? Common ancestry. Why are there transitional fossils that span the chimp-human morphotype? Common ancestry. Common ancestry
predicts these patterns, and that is why the evidence I just cited is considered to be so strongly in favour of evolution. Ad hoc appeals to "common designer" predict no such patterns.
and in the creationist view and timescale improbable also.
That's not saying a lot. Creationists can't even agree on a time scale. Is the earth 6,000 years old? 10,000? 100,000? No one seems to agree.
The kinds of evidence that you are talking about do not have the same level of credibility in proving current relationships relevant to crime cases because they do not have the same time scales of causal patterns as the more immediate and demonstrable reproductive patterns we are familiar with for example.
Actually, the time scales of causal patterns are exactly the same. The process that causes a population to split and become reproductively isolated is that which leads to macroevolution over the course of thousands and millions of years.
If you're arguing that we cannot SEE humans evolve from chimps in real-time, I agree. Then again, we can't SEE John kill Joe again because it's an event that happened in the past and there were no witnesses. We have to use forensic evidence to determine the likelihood that John did, in fact, kill Joe. Similarly, we use forensic evidence to determine the likelihood that humans share a common ancestor with chimps. The verdict is reached based on the weight of the evidence. And according to the vast majority of scientists (and court rulings), the evidence for evolutionary common ancestry is overwhelming.
The similarities are significant but they do not prove relationship
Nothing in science is proven. But evolution is beyond reasonable doubt, and that is the yardstick used in the court of law, which is what we're discussing.
I think you realize how impossible it would be to accept "it was a miracle!" as evidence for anything in the court of law...
"I swear, your honour! I don't know why that baby has half my DNA, but I didn't get that lady pregnant! It was a miracle!"