If you mean there are no assumptions in the process of science, I have to disagree. While the idea of science is to test theories, in practical fact it is built on top of assumptions like just about all other human undertakings with the exception of specialized trains of philosophical reasoning like Renee Descarte undertook to find out what happens when you make no assumptions.
One can only really test assumptions on a particular level. In any modern experiment there are going to be a lot of things one depends on working including over arching theories, lab techniques, lab equipment, and so forth. For better or worse, Evolutionary scientists are getting grants to operate within the framework of evolution as a given and focus on details.
I agree it’s necessary to make some assumptions, but assumptions that are created solely to protect a theory are not legitimate science, and shouldn’t be assigned any credibility by an objective individual. Evolution is essentially a gigantic pile of such assumptions.