Well "evos" have in fact shown that adaptation occurs. Isn't it your job to find these supposed limits to adaptation that would prevent evolution from occurring? Once a critter has adapted to "something" what is to stop it adapting to something else then something else and eventually changing significantly?Evo wofflers do things like bring up ecoli and shove somatic changes in evolutionists faces as examples of 'evolution & something else' because they have no way of demonstrating limitless adaptation.
As for demonstrating large scale evolution directly, you know that is impossible in the lab given the time frames we have available. It is demonstrated amply enough in the nested hierarchy of the fossil record and the genome's matching nested hierarchy of variation.