Science doesn't claim evolution to be absolutely true because it doesn't claim anything to be absolutely true, even gravity. It's simply the theory with the most evidence, that fits with our views of the way the world works that have been tested and tested against with generally consistent observations supporting the theory. Science also doesn't claim to be able to explain anything outside of the natural world, and assumes that there is a logical explanation for everything. Basically if you don't believe in evolution fuck you why do you trust that medicine that you've never taken works.