It's a small molecule world after all

I've discussed a lot about evolution with my computational biology group (and we've published some great papers on it). We arrived at the conclusion that the discussion about RNA vs DNA vs protein first world was misleading since really the first things to come out of the primordial soup had to be small molecules!

But small molecules had to be alive in some sense. What is the definition of life? We can argue about that forever, but let's just that if a molecule finds a way to transfer information to make a copy (where other molecules cannot), then evolutionary forces will likely ensure that way is "fit". That's good enough for me and if you look at our universe there are other things that have been tried by evolution to have life-like properties but they've not gone anywhere in the sense that biological life has. But like them, small molecules have persisted for billions of years completely unchanged in many cases and have developed elaborate mechanisms to ensure that their copying will remain universal. (For the record, I don't think molecules and evolution are sentient/conscious. I just am anthropomorphising them.)

I've argued (as Stephen Gould did) in the past that it's a bacterial universe after all, that bacteria have evolved over billions of years and the side effect is all these other life forms that are vessels for bacteria and one of these life forms is sentient (capable of genetic engineering).

But when you think about it, it's the small molecules that have been doing this! Evolution has created a system where small molecules can be copied and reproduced. Small molecules, which could be a single atom, have really developed innovative ways of being useful to the other organisms that later evolved that these small molecules are ubiquitously copied and used. These small molecules take on the role of being the fundamental units of RNA, DNA, and proteins, as well as performing a vast variety of biological functions. In humans we not only have small molecules functioning as neurotransmitters, we also have drugs that we can become addicted to that propagate through the population. I talk about proteins doing stuff a lot, but proteins also would not be very useful without the right environment and in many cases a small molecule or single atom to aid them.

Humans themselves have created new small molecules that are now copied ubiquitously.

Pseudointellectual ramblings || Ram Samudrala ||