So in other words we see appearances of design and we see appearances of patterns of similarities in organisms but we are going to go with the conclusion that it is all natural in origin because.....??....an intelligent designer can't be an answer?
We don't just see "appearances" of patterns of similarities in organisms.
Instead, we
observe actual patterns called nested hierarchies. They don't "appear" to be there. The
are there.
And they require an explanation. Evolution theory offers a perfectly viable explanation. It can be tested and is falsifiable. It is put to the test with every new genome sequences, with every fossil that is dug up, with every new species that is discovered. It's as solid a theory as they come.
Your "intelligent designer" is not an acceptable answer. For 2 reasons:
1. we already have a viable and sufficient theory. That's not to say more factors could come into play that we currently know of, but you'll require evidence to suggest them.
2. the reason you suggest your designer is not because of you have valid evidence to support it... it's because you are required to believe that a designer is involved due to your a priori religious beliefs. Why should scientists, or indeed anyone else, care about your faith-based beliefs and biases when it comes to explaining the phenomena of nature?
I have seen many scientific sources that get things right and also get things wrong (from the Christian perspective) in the same source. A lot of it is assumptions based on the naturalistic viewpoint mixed in with the facts.
99% of all proposed ideas in science are wrong. That's how you make progress. Investigate your ideas and those of your peers and prove them to be wrong. The few ideas that stand tall after that merciless process, are the theories we all know today: evolution, atoms, relativity, electro magnetism, germs, ... etc.
It's called "learning". In the words of Dr Krauss: "some people would rather read an ancient book, instead of learning".