Or so they think at MSNBC. In “Can life evolve from a different chemical code?” (8/19/2011), Clara Moskowitz tells us, “Scientists ponder if life elsewhere is based on another set of amino acids.”
Other, that is, than the 20 – among hundreds – that build life’s known proteins:
“Life has been using a standard set of 20 amino acids to build proteins for more than 3 billion years,” said Stephen J. Freeland of the NASA Astrobiology Institute at the University of Hawaii. “It’s becoming increasingly clear that many other amino acids were plausible candidates, and although there’s been speculation and even assumptions about what life was doing, there’s been very little in the way of testable hypotheses.”
Along with colleagues, he discovered that
… life seemingly did not choose its 20 building blocks randomly.
“We found that chance alone would be extremely unlikely to pick a set of amino acids that outperforms life’s choice,” Freeland said.
So there is only one possible answer:
Natural selection
The story is,
“Here we found a very simple test that begins to show us that life knew exactly what it was doing,” Freeland said. “This is consistent with the idea that there was natural selection going on.”
No, it is not. Natural selection is blind to outcomes. That was the point, remember?
Turns out it’s “experimentally difficult” to find out any more.
We’ll be back here at origin of life in 1, 2, and 20 years. Same station, Same show. Same theme. Some new cast members.