Bringing the known number to twelve:
The genetic code that dictates how genetic information is translated into specific proteins is less rigid than scientists have long assumed, according to research published today (November 9) in eLife. In the paper, scientists report screening the genomes of more than 250,000 species of bacteria and archaea and finding five organisms that rely on an alternate genetic code, signifying branches in evolutionary history that haven’t been fully explained…
“The genetic code has been set in stone for 3 billion years,” study coauthor Yekaterina Shulgina, a Harvard University graduate student in systems biology, tells The Scientist. “The fact that some organisms have found a way to change it is really fascinating to me. Changing the genetic code requires changing ancient, important molecules like tRNAs that are so fundamental to how biology works.”
As such, the code was thought to be largely preserved across all forms of life, with scientists finding the occasional exception during the past several decades of research. In addition to finding five new alternate genetic codes, the team also verified seven others that had been discovered one-by-one in the past, bringing the total number of known exceptions in bacteria to 12.
Dan Robitzski, “Screen of 250,000 Species Reveals Tweaks to Genetic Code” at The Scientist (November 9, 2021)
Apparently, it was not set in stone. Not only was it very complex very early but it can be complex and different and still work. By now, Darwinian dogmatism is beginning to sound ridiculous.
The paper is open access.