Imagine an alien world ruled by "advanced dinosaurs" as smart as humans—maybe even smarter.
Science fiction? Not necessarily, says the author of a provocative new study whose title--“Evidence for the Likely Origin of Homochirality in Amino Acids”—gives no hint of any worrisome extraterrestrial implications.
Published in the March 25 issue of the "Journal of the American Chemical Society," the study addresses the chemistry of amino acids here on Earth. But study author Dr. Ronald Breslow, a professor of chemistry at Columbia University in New York City, said in a written statement the work suggests that if life forms do exist on other planets, they “could well be advanced versions of dinosaurs."
It’s long been known that certain molecules, including DNA and amino acids, exist in two mirror-image forms—a phenomenon known as chirality. And with few exceptions, the amino acids that make up the proteins in life on Earth exist only in the L (left-handed) form. The question is how did this “homochirality” come to be?
Some scientists have speculated that the amino acids that predominate on Earth came to our planet via meteorites four billion years ago. And if that’s what happened on Earth, Dr. Breslow said in the statement, it’s possible that life that might exist on other planets could be based on D amino acids.
From there, Breslow makes the jump to advanced dinosaurs. But why might extraterrestrial life be in that form? “Because mammals survived and became us only because the dinosaurs were wiped out by an asteroid, so on a planet similar to ours without the asteroid collision it is unlikely that human types would be there, more probably advanced lizards (dinosaurs),” Dr. Breslow told The Huffington Post in an email.
Not everyone is convinced.
“Animal-like creatures that might evolve on other worlds will not be and cannot be dinosaurs,” Dr. Paul "PZ" Myers, associate professor of biology at the University of Minnesota Morris, wrote on his blog. “There is no reason to imaging that a saurian-mammalian transition is anything but a particular quirk of our particular planet’s evolutionary history—it is not a universal.” Dr. Myers termed the paper “badly written nonsense.”
Of course, if advanced dinosaurs could exist on other planets, we might want to rethink our efforts to make contact with extraterrestrial life. Says Breslow of the brainy dinos he imagines, “I just warn that they might well see us as food.”