I have never stated that the validity comes from the reputation of the author. What I am saying is that in this context it is not appealing to authority by deferring to the expert in this field of study. It is very likely that the expert in the field of study is going to have a better grasp on drawing conclusions from the data set than a layman would.
That's a change in your tune - before you said "The only other people who are capable of drawing conclusions on this data set would be other ichthyologists." (emphasis mine)
You noted "very likely" in that last bit but likelihoods aside, it's the idea that matters. That is why I asserted "Anyone who has access to the evidence he has collected could draw conclusions and might be more successful in deducing the significance of the evidence or extrapolating patterns from the evidence than the ichthyologist." As you mention below with Einstein, it is the virtue of the theories themselves that is important within science, not the reputation or resume of the theorist.
Conversely, take an example from religion: per the Roman Catholic doctrine of Papal Infallibility, the pope's pronouncements upon certain types of Catholic spiritual matters are infallible - not because of any quality of the ideas themselves but because he's the pope. Before empiricism the attitude in academics was often similar: Livy's interpretation of the meaning of events in Roman history was the correct one because Livy was the most reputed Roman historian.
I'm not sure what point you're trying to make with this? I don't think anyone is suggesting that an expertise is an innate ability. It is something that is earned. In Einstein's case, he earned it by having his theories withstand the scientific process.
You've got no idea what this would have to do with the current discussion, huh?
The point I am making is that Einstein did not possess the title "theoretical physicist" yet he was far more capable of and successful in his analysis of the contemporary evidence than many of his peers who officially held the title, men would would have won far more regard as specialist experts than a patent clerk. It is not the case, as you stated, that only the specialist like the ichthyologist is capable of drawing conclusions from his data. And that's the case regardless of whether the specialist's expertise is innate or acquired.
Depth of experience certainly can aid in scientific analysis as it can with any skill. And as a matter of practicality scientists are going to primarily spend their time contemplating and working on new ideas from people who have "earned their chops" as opposed to pursuing any new idea at all which they're exposed to. But an important feature of empiricism and the scientific approach to knowledge, distinct from the forms of epistemology that preceded them, is that the validity (or "truth", to get old school) of an assertion is vested solely in the assertion itself and has absolutely nothing to do with the prestige or other characteristics of the author of that assertion.