"creating human-animal hybrids"
Let's take the hybrid mouse Dr. Myers mentioned. It's a mouse with a human gene. Is it still what we'd feel comfortable calling a "mouse"? What if we added the whole human chromosome 21? I'm inclined to say that it is.
What if you take a human stem cell (embryonic, adult, whatever) and add a mouse gene? This, I suspect, is what gets the President all freaked out. Is a human cell with one mouse gene still human? What if you add a bunch of mouse genes?
I say that, just as the mouse cells stay mouse cells, the human cells stay human. It's like my grandfather's hammer. He replaced the handle a couple times, the head got rusty and had to be replaced, and my dad's had to replace the handle, too. But that's a great hammer.
When the first heart transplants were attempted, people got all freaked out. The heart was what made people special, and removing a beating heart seemed like murder to some people.
But people thought about it, evaluated the science, and evaluated their own ethical concerns, and decided that brain death was a more reasonable way to understand death, and that organ transplants were necessary.
Right now, replacing one species' genes with another's seems scary to some people. And it's important that scientists explain what they are doing. That covers the proximate issues, but it doesn't get to the ultimate issue of human identity. That's a different conversation.
George Bush's tendency to simply ban research avenues that he finds problematic doesn't get to that conversation. This is what I mean by Bush not making an effort to change people's minds.
Modern science can push us into complex territory. Improved neonatal care and better life support force us to explore the formerly undistinguishable boundaries of life, its beginning and end. Genetic technology lets us explore different frontiers, as geology, chemistry and biology push toward the beginnings of life on earth, and physicists learn more and more about where the universe came from, and where it might be going. The science itself doesn't address the complex philosophical questions, but many people find that the scientific advances challenge something they thought they understood about the nature of reality, the fundamental trust they've placed in how they understand those boundaries is shaken.
Simply banning the research won't rebuild that trust. We have to move forward and have a dialog about the ultimate issues raised by the advance of science. President Bush has made up his mind, but that doesn't mean the nation has reached a consensus.