What is your theory on penguins?
Well, you asked.
My theory on penguins dovetails with my theory on other animals such as horses/zebras, lemurs/racoons, cheetahs/leopards, etc., etc. etc. I'll need to lay out *my theory* of the post-Flood world to convey it. Obviously I can't back any of this up, and it won't be exhaustive.
-The "ice age" was a result of the Flood, and the reason the ark landed
when it did was because the massive polar ice caps had locked up enough water to expose land bridges between all of what we now call "continents". These land bridges might have been exposed for decades, centuries, or longer.
-People and animals would have been able to migrate, on foot or wing, anywhere in the world that wasn't covered in ice, and they did.
-Populations of different people and animals went their separate ways occasionally, case in point, puffins. I.e., different families of puffins migrated in different directions and ultimately ended up in different parts of the world.
-The puffins that ended up in the southern hemisphere, for whatever reason, had nothing to eat except whatever they could fish from the seas, so they adapted to their marine environment. Their anatomy necessarily developed such that they had to swim and dive to survive and ultimately lost their ability to fly. They became penguins. This is over decades or hundreds of years, not millions.
-After decades (or whatever) of what could be called "global thawing", the aforementioned land bridges became submerged, the different populations of these now-penguins became isolated from each other, and they further adapted to their respective environments resulting in the many different sizes and shapes of penguins that exist today.
-Conclusion: Puffins and penguins were originally the same kind of birds, but have since diverged into completely different species and sub-species of birds that are no longer able to produce offspring with puffins.
*Most of this I learned from watching Kent Hovind's video "The Hovind Theory", and I filled in some of the blanks on my own, but I want to give credit where credit is due. Like Brother Hovind says, you can learn something from everybody, just eat the meat and spit out the bones.