Attention Scientists: Do you want a swimming pool full of gold coins to Scrooge McDuck through? Enough bling that you can fund and found your own Mars colony? Perhaps you have the simple desire to build a fourteen bedroom treehouse wherenin all the rooms are connected by a series of ziplines.
Well then. Allow me to introduce you to Mesohippus, if you didn't already know them:
(Image Source: Wikipedia)
For those of you not in the loop, Mesohippus was a proto-horse that lived 30-40 million(ish) years ago. While most of the past was full of hillariously giant things, Mesohippus went the other direction and was comicly tiny -- it was about 2 feet tall and hadn't yet developed the single toed hoof we're so familiar with today. And, in the right hands, it could be a gold mine.
"But Tetra," the males among you inquire wryly, "How will I achieve enough money to build a full sized marble pyramid with tiny horses?" The females among my audience won't be asking this because they'll already be running to their laboratories at breakneck speeds having anticipated where I'm going with this. Hell, there might not even be any female scientists in the audience because they're already so busy at their cloning benches* having thought of this already.
They remember being a little girl you see. And if they weren't a little girl who was completely nuts about horses, then I assure you they knew at least twenty other little girls who were. This equine adoration has resulted in such industries as My Little Ponies, Breyer model horses**, websites such as Howrse and even the collectable card game Bella Sara. But more than pretend horses what these girls crave with a fervor is a real honest to god horse.
But horses are big, eat a lot, crap a lot, and more than a little expensive. Mesohippus fixes three out of four of those problems. All it would take is a few successful clonings and then a couple of generations of breeding for domestication, ala the silver foxes. Build (or in this case, replicate) a better horse and the screaming hordes of little girls will trample a path to your door.
Sources/Further Reading:
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* Or whatever secret and most likely non-existant device it is they use to clone 30 million year old animals.
**To clarify the extent of this phenomena you must note there are model horse shows.