Hachimoji DNA argues against Evolution

DNA blue

…despite recent claims

by Matthew Cserhati, Robert Carter

The headlines were bold:

“Four new DNA letters double life’s alphabet” (Nature)

“Scientists successfully double the DNA alphabet” (The Smithsonian)

“DNA gets a new – and bigger – genetic alphabet” (The New York Times)

“Synthetic doubling of life’s DNA alphabet suggests there’s nothing ‘magical’ about life on Earth” (The Genetic Literacy Project)

A research group led by Dr Steven Benner at the Foundation for Applied Molecular Evolution (FAME) in Alachua, Florida has created four extra DNA letters. They recently published a paper on their work in the prestigious journal Science and, as we have already seen, it caused a flurry of ‘tweets’ and re-postings. By tweaking the structure of the already-existing four bases, adenine (A), cytosine (C), guanine (G) and thymine (T), they have expanded the DNA alphabet from four to eight letters. The two extra pairs of letters include ‘S’ and ‘B’, and ‘P’ and ‘Z’. The researchers have named the resulting eight-letter alphabet “hachimoji”, which is Japanese for “eight” and “letter”.

But Benner’s team merely tweaked the molecular structure of the four already-existing bases. P and B are purine analogs (similar to A and G), whereas S and Z are pyrimidine analogs (similar to C and T). The two new pairs of bases also pair with three hydrogen bonds, similar to the way C and G bond to each other when placed opposite each other on complementary strands of the DNA double helix.

These four new nucleotides are interesting, but they are not truly innovative. How about a pair of bases with four hydrogen bonds? Or a base with a steroid structure, like that of progesterone or testosterone? No, they are not pursuing radical new structures like these, because humans are better at copying and modifying existing things than they are at inventing brand new things from scratch. In the end, all of their work testifies to how much thought must go into the designing of any new ‘thing’. Despite the headlines, this argues against naturalistic evolution…


image credit: geralt