Some recent evidence points to the Earth’s magnetic field playing a part in preferentially selecting right-handed chirality in RNA precursors. This work is not complete though as not every nucleotide can be made from this process yet, but it is so far, the best explanation available as to why genetic material and amino acids are exclusively R and L (respectively) oriented.
Thank you for sharing!
This mechanism is interesting, but I am still not convinced that a basing mechanism operated during the origin of life. As the article mentions: chirality is important for life. At some point life had to pick one - L or R - And life was forced to make a choice. Even if the chance is 50 / 50, life still had to make that choice. A biasing mechanism might change the probability of choosing L or R, favoring one over the other, but unless the bias is substantial then there is a chance that life would have picked the other less likely option any way!
Of course, I can’t know for sure! Perhaps there is a mechanism that is so strongly biasing that it must have been L or R, and so it is absolutely worth to keep looking.
If anyone is convinced that a biasing mechanism likely played a role, please explain to me why!
I also remain sceptical. I don’t think there necessarily must be some mechanism to break the symmetry, it could have just been a cosmic coin flip. This is different than something like matter/antimatter in which there needs to be some underlying physical process introducing a bias.