Um....so.... scientists don't claim that whales descended from any of the animals who's remains that have been found but are very likely to have descended from some other animals who's remains have not been found. Have I understood you correctly?
Yes. There is a chance that whales are descended directly from Pakicetus, but it's not something scientists claim.
Are you aware of any scientific studies confirming that any of the others animals who's remains have not been found ever reproduced?
Obviously there aren't any. There aren't any for the animals whose skeletons have been found.
That observation is being used to determine where the bones have been found and their degree of similarity was not questioned. Once those things have been observed the proposal is then being tested by interpretation. My question was, is this scientific? Can we say that it has been proven by science? I would contend not.
Being a lab has nothing to do with repetition. It may make the repetition easier to accomplish but it is not a requirement of it.
If it cannot be tested, so that it can be proven or disproven, then it is not science. Science requires testability.
Ok, glad you are focussing on testability rather than the lab aspect.
The difficulty here for evolution is that it will never be possible to demonstrate that an individual fossil left offspring which evolved into a different species. This is the real world situation. The evidence simply doesn't exist and will never exist to allow us to do this. We couldn't even gather this data on species that are living and reproducing now in wild conditions. That's why scientists don't claim individual fossils are ancestral to another species (with a few exceptions).
So is the assertion that Pakicetus is a transitional species between something else and whales testable?
In the sense that you mean it, I believe not - if you are looking for a direct chain of evidence that connects fossil A directly to whale B via every intermediate link in the chain.
However, a fossil must meet certain criteria to be proposed as a transitional. For example, the timeframe must be right. It must show a mixture of features of the classes of organism it is alleged to be transitional between. These are testable (ie could be falsified by further analysis of the fossils, or finding of more fossils) and the latter in particular is where paleontologists do most of the work in analysing 'transitionals'.
So it's clear that fossils exist, with features intermediate between other fossils.
Is the assertion that they evolved one into the other testable? No.