I know that is what the cute creationist cartoons indoctrinate kids "no one has seen it happen" and I'd bet you have been indoctrinated. If you have any influence on AIG and DI please tell them to spend some of the millions they raise on actual scientific research.
There is plenty of evidence for speciation:
29+ Evidences for Macroevolution
The Scientific Case for Common Descent
My favorite is
:
How Dinosaurs Shrank and Became Birds
Modern birds appeared to emerge in a snap of evolutionary time. But new research illuminates the long series of evolutionary changes that made the transformation possible.
“A bird didn’t just evolve from a T. rex overnight, but rather the classic features of birds evolved one by one; first bipedal locomotion, then feathers, then a wishbone, then more complex feathers that look like quill-pen feathers, then wings,” Brusatte said. “The end result is a relatively seamless transition between dinosaurs and birds, so much so that you can’t just draw an easy line between these two groups.”
It's my favorite because I've enjoyed having my own living dinosaurs from a young age.
I think you are missing the point.
Cats are cats, dogs are dogs NOW, but they
trace to common ancestors who were neither
a "cat" nor a "dog".
As for what a few tens of millions of years might
do-
There are wolves on a Pacific coast island that
get their food from the ocean.
Should it be the case that the ability to go further,
swim faster, dive better proved a great advantage
and ten million years later those wolves now looked
an awful lot like sea lions, well, I suppose one could
SAY, "nope, still dogs".
If later still you had 1000 pound "dogs" that could stay at sea for
months, we'll, say they stayed dogs if you like.
Or say leopards and poodles are still the common ancestor of both.
In a sense that is correct.