Polymerization of L- and DL-phenylalanine N-carboxyanhydride by poly(N-methyl-L-alanine)

The Asymmetry of Existence: Do We Owe Our Existence to Cold Dark Matter and the Weak Force?

A common theme throughout biology is homochirality, including its origin and especially implications. Homochirality has also intrigued scientists because of the hypothesis that life, as it currently exists, could not have occurred without it. In this review, we discuss several hypotheses regarding homochirality and their linkage to processes that range from subatomic in scale to processes that help define the structure of the universe. More importantly, this exploration begins with the knowledge that humans inhabit the universe in which there is an excess of normal matter over antimatter. It is a universe characterized by homochirality but is nonetheless contained in what is most easily described as a 3+1 dimensional spacetime wherein most laws of physics are invariant under spacetime transformations. This restriction on spacetime poses significant constraints on the processes that can be invoked to explain homochirality. However, in dealing with such restraints, including the total mass contained in the universe, the concepts of cold dark matter and dark energy can be incorporated into cosmological models with resultant behaviors and predictions very much in accord with the findings of the cosmic background surveys. Indeed, the introduction of cold dark matter and dark energy to solve problems relating to the mass found in the universe may provide a means for generating the needed asymmetry to allow homochirality to arise.