They can't analyze the DNA of their last common ancestor unless they already know what their last common ancestor is (and have a living organism to analyze). This assumes evolution in the first place (as we ll as assuming what their last common ancestor is). In other words you once again assume evolution as your starting point. Having "determined" that their "last common ancestor" lacks the shared trait, "convergent evolution" is now the necessary assumption, which somehow becomes "science".
Assumptions are not science at all, which is basically the point of the whole article.
Similar features not present in a common ancestor can be said to result from "convergent evolution". Of course, you are free to reject its assumptions, but the science is consistent and confirmed innumerable times.
All you're doing is repeating the definition of convergent evolution, not providing evidence for it. What you're calling "the science" is, once again, assuming everything is the product of evolution. Therefore the "evidence" for convergent evolution is a direct result of circular reasoning.
You're perfectly illustrating Lee Spetner's statement.
If you draw a phylogenetic [relationship] tree of bats, whales, and a few other mammals based on similarities in the prestin [a hearing gene] sequence alone, the echolocating bats and whales come out together rather than with their rightful evolutionary cousins.11Addressing this specific contradiction, Lee Spetner perceptively observes:
Convergent evolution is…an invention. It was invented solely to avoid addressing the failure of the phylogenetic tree to support Common Descent. There is no theoretical support for convergence, and whatever evidence has been given for it is the product of a circular argument.12
If you mean there are no assumptions in the process of science, I have to disagree. While the idea of science is to test theories, in practical fact it is built on top of assumptions like just about all other human undertakings with the exception of specialized trains of philosophical reasoning like Renee Descarte undertook to find out what happens when you make no assumptions.
One can only really test assumptions on a particular level. In any modern experiment there are going to be a lot of things one depends on working including over arching theories, lab techniques, lab equipment, and so forth. For better or worse, Evolutionary scientists are getting grants to operate within the framework of evolution as a given and focus on details.
Nonsense, since all of science is an "invention" -- that's what words like "hypothesis", "theory" or "analysis" imply: scientists inventing natural explanations for observed data.
"Convergent evolution" is a hypothesis / theory strongly confirmed by innumerable observations of extant species, the fossil record and DNA analyses.
Of course, as I posted before, if you reject the idea of evolution itself, then "convergent evolution" will make no sense to you.
But in terms of the science, it's consistent with all the evidence.
lasereye: "Having "determined" that their "last common ancestor" lacks the shared trait, "convergent evolution" is now the necessary assumption, which somehow becomes "science". "
No, not "somehow", like any scientific idea ever, it is first presented as a hypothesis which if confirmed is called a theory.
The convergent evolution hypothesis is confirmed by innumerable observations, making it a scientific theory.
That's how science works.