There was a Nova the other night that was remarkably interesting, about a family in Turkey that walks on all fours.
Alot of it delved into genetics, and it talked about how scientists are still stunned that most of our genes are shared with most other critters.
For instance there is a gene called FOXp2 that enables humans to have speech.
Thing is, dogs have it. Birds have it. But the version in humans underwent two major mods in the last 200,000 years or so. (Don't ask me how they know that)
If we took the human version and spliced it into a dog???
But nonetheless, I agree with you. My position wouldn't be that it was impossible, but that it is vanishingly rare.
We share an incredible commonality with other critters, in both genes which produce a visible distinction in an organism (phenotype) and those that control growth, and those that produce hormones, etc. Think of how similar the structure and proteins are among all mammals eyeballs, bones, sockets, the fact that appendages grow with some symmetricality...
Researchers will often use knowledge about a gene that has been studied in one organism to help them understand it's function in another. One of the ways that a gene's action is discovered is by knocking it out and seeing the result in offspring. Its easier to manipulate a gene and breed future generations for some small organisms (zebrafish, fruitflies, yeast) and learn from that, and then use that knowledge to better understand organisms which you won't have to experiment on - ones which have longer breeding times, ethical concerns, or legal representation:)
<< For instance there is a gene called FOXp2 that enables humans to have speech. Thing is, dogs have it. >>
I saw a sign once in front of a house, "Talking Dog for Sale."
I rang the bell and the owner told me the dog was in the back yard.
I went into the back yard and saw a mutt sitting there.
"You talk?" I asked.
"Yep," the mutt replied.
"So, what's your story?"
The mutt looked up and said "Well, I discovered this gift pretty young and I wanted to help the government, so I told the CIA about my gift, and in no time they had me jetting from country to country, sitting in rooms with spies and world leaders, 'cause no one figured a dog would be eavesdropping. I was one of their most valuable spies eight years running.
"The jetting around really tired me out, and I knew I wasn't getting any younger and I wanted to settle down. So I signed up for a job at the airport to do some undercover security work, mostly wandering near suspicious characters and listening in. I uncovered some incredible dealings there and was awarded a batch of medals.
"Had a wife, a mess of puppies, and now I'm just retired."
I was amazed. I went back in and asked the owner what he wanted for the dog.
The owner said "Ten dollars."
I said to the owner, "This dog is amazing. Why on earth are you selling him so cheaply?"
The owner replied, "He's a liar."