Ok, this one took me by surprise. “Man-made DNA“, the headlines don’t seem that shocking. But then I looked a bit inside. The folks here are not just doing genetic engineering, but actually adding new base pairs to the DNA alphabet.
It’s not your grandmother’s DNA! … she had four base pairs with the ability to create twenty amino acids — all of which is a shared organic chemistry with every other living thing on earth (and I’d assumed, until today, other “goldilocks” planets.) I recently competed the free Udacity course, sponsored by 23-and-Me, on how the … what do we call them now … “legacy” DNA pairs… work. Researchers at Scripts Institute in San Diego have managed to find two additional molecules for a new base pair set, that “works” in DNA. They can insert them into bacteria, the bacteria reproduce, and these pairs get copied just like the legacy pairs. This expands the range of amino acids that can be produced to one hundred and seventy two — that’s one hundred and fifty two more building blocks to play with in building organisms. Depending on how “likely” these two additional bases are in a given planetary chemistry set, this means we might find DNA based life-forms that simply don’t use the same base pairs that we use.
So what? That’s the big question in my mind. Our ability to understand the translation of base pairs into proteins into amino acids into cellular components into cells into life forms is somewhat limited at this point. Give a genetics wizard a new mutation and ask what impact it will have and she won’t have a clue. Needless to say, give our wizards one hundred and fifty two new building blocks and they will be clueless. If some of these do good things, we can expect some of them to do bad things — although it is likely that most will do nothing at all.
It took four and one half billion years of playing with the chemistry set on Earth to come up with the thousands of species we have, and thousands of extinct species — presumably guided by the “invisible hand” of evolution. No doubt we can incorporporate these additions to our “kit” in a tenth of that time (i.e. five hundred million years.) — (are we there yet?) … with a bit more carefully managed range of speciation and extinction. It’s just the first million years I worry about.
Humans have not demonstrated a great deal of global responsibility in dealing with today’s challenges — governments, corporations, institutions and individuals tend to operate with short-term, self-serving agenda’s — even when they are presented with fairly solid evidence that their courses of action are harmful. The new Cosmos series on TV does an excellent job of demonstrating that in a recent sequence on the dating of the universe (the transition of uranium into lead) and the closely related battle to stop poisoning the planet with lead in gasoline. When we move forward into an arena where we have limited or no visibility we need to tread very carefully, at least.
How do you see this next opportunity in evolution?