Big Gaps and Short Bridges

The paper Big Gaps and Short Bridges: A Model for Solving the Discontinuity Problem,  by Change Laura Tan, appeared in Answers Research Journal (vol 9 (2016): 149–162), and argues that the primary problem with the origin of life and the origin of biodiversity is not an issue of time, but rather the unbridgeable discontinuities among different life forms. Many mathematicians, for example, believe these cannot be bridged by the mechanisms of random variations and natural selection. 

The author proposes anew model designed to more accurately reflect the relationships between living things on earth, aiming to facilitate the functional annotation of genomes and the classification of organisms. It does this by integrating the observations of fossils, gene function studies, and sequencing of various genomes, along wit lessons learned from molecular cloning


Deeper Dive

The author describes her approach this way: “My working model is that all organisms on earth can be organized into a forest of family trees. Branches on the same tree are all offspring either of one asexually reproducing parent, or of a population of ancestors that contain the same genes, or of a pair of sexually reproducing parents. Lines in between different family trees link characters (phenotypes, genes, or pathways) that are shared among organisms that do not belong to the same family trees. These characters include the many cases of alleged convergent evolution. I think such characters reflect the modular nature of life. In a nutshell, two key concepts, or hypotheses, or assumptions, in the model are that life is modular and that not all organisms belong to one family tree. Each organism is a combination of multiple modules. A module can be a signal transduction pathway, a biological process, or a special structure.