The evidence is entropy and complexity. The science of these 3 things proves it evidently. No complexity in the magnitude within the universe without intelligence. Entropy shows that ultimately, there is always less complexity. Something far greater in intelligence started this whole thing. That's the only evidence that exists.
What's the evidence that complexity requires intelligent design? ''Something far greater in intelligence started this whole thing. That's the only evidence that exists.'' Even if that was the case, it doesn't mean it's an omnipotent all knowing god, something more intelligent than what btw?
The evidence is the examples in nature, especially those of human beings. If there was any great amount of evidence opposing these examples, there might be cause to think that complexity could arise on its own. But there isn't.
In other words, when we examine and correlate the intelligence behind the great numbers machines of intelligent man, plus the few simple machines of a few slightly intelligent animals, we see that intelligence makes machines, right? And the greater the intelligence, the greater the machines, right?
Which of the structures of any of the natural things on earth is not made up of machines? None of it. Even the complexities of subatomic particles reacting with each other is leverages upon leverages reacting with other leverages, both in material ways and in energy ways. This is what machines are! All, 100% of nature, is machines upon machines combined in a gigantic machine universe. And all, 100%, of our machines uses the examples of machinery found in nature, and the machines of nature themselves, one way or another in their design and operation.
Machines have makers. So, why would anyone think that the great machinery of nature, which has tremendously intelligent design to it, not have an Intelligent Designer behind it? We have no example of any intelligently designed "thing" that doesn't have an intelligent designer behind it. The closest we can come is to say that we don't know who the designer is.