One such discovery would be putting a mix of chemicals in a test tube, waiting a while and seeing a human race emerge.
Life didn't come to be in a test tube. And do you mean by "a while" 500 million years (or more), which is what it is likely to take? Clearly, you're joking about this. On the other hand, it could happen tomorrow that a 50-million-year-old layer of sediment is dug up that contains a fossil that falsifies current evolutionary accounts of the developmental history of life on Earth.
I realize it is not possible to produce such evidence for reasons of timeframe. I am willing to consider a less direct evidence, such as, for example, manipulating the process with accelerated changes in the chemical environment in order to artifically speed up the mutation/selection apparatus. I would also take any complex form of life, not necessarily a homo sapiens, as a result.
Nevertheless, I provided an answer to the question you posed, since your question did not ask: Which discovery that is easy to make would falsify the theistic or Intelligent Design view? -- it simply asked if such discovery were conceivable.