I didn't see a direct comment section for the article and I thought it might be a good topic for this forum. You can find the original article here:
Is historical science reliable?
One of the common misconceptions that I see on this topic is the confusion between observations and hypotheses. Critics of historical science claim that it isn't scientific because the past isn't observable or repeatable. The mistake they make is that our explanations for what happened in the past are hypotheses, not observations. In the scientific method you don't observe the hypothesis. The hypothesis and observations are two different things.
Let's use the recent discovery of the Higg's Boson as an example. You might say that they observed the Higg's Boson, but you would be wrong. Instead, they saw an excess of photons that were created during collisions of a certain energy. Not only that, but these photons were measured after the decay of the Higg's Boson, so it is really historic evidence, even if it is only going back a few nanoseconds. On top of that, scientists did their initial analyses on computer recordings that were created in the past. A vast majority of evidence and observations in science are either indirect or from the past.
For evolution, it is no different. Our hypothesis is that species share a common ancestor. The observations are of fossils and DNA, items that are in the present and can be verified through repeated observation. These are like the excess photons at CERN which told us that a Higg's boson decayed in the past. These are just like the computer recordings of the particles spewing out of the LHC.
In science, you test a hypothesis by predicting what you should see if the hypothesis is true AND what you shouldn't see if the hypothesis is false. There is no inherent time limit on how long the evidence can sit around before it is no longer considered an observation. If you can accurately and repeatedly measure something then it is a valid scientific observation. If your hypothesis makes predictions about future observations, then it is scientific. The theory of evolution and the evidence that supports it fills all of those requirements.