Molecular Evolution

written by: Liran Carmel

last modified:

Origin of life
The Apearance of the first self-replicating organism seems to be a phenomenon of irreducible complexity. Koonin, based on prevailing cosomolgical theories, shows how such irreducible complexity must appear in an infinite universe, and then, by the anthropic principle, maybe it happened here (K2007a).
One of the most puzzling questions is how the translation system evolved. Assuming fully functional RNA world, Wolf & Koonin are the first to propose a scenario for the development of the translation system that adheres to the Continuity Principle in evolution (WK2007).
Detecting paralogs and orthologs
A nice survey of techniques is given in Sennblad & Lagergren (2009). They advocate their own technique, which is based on a probabilistic approach (SL2009).
General trends in evolution
It is customary to imagine the evolution of species using bifurcating tree. It was noticed by Koonin that major evolutionary transitions, such as the origin of protein folds, the origin of viruses, the origin of cells, and the origin of major phyla (bacteria, archea, eukaryotes, animals) are better described as a bush rather than as bifurcating tree. Such bush-like evolution is characterized by appearing occasionally for only short time intervals, and is hypothesized to be mainly caused by HGT (K2007b).
Literature
NewIdea Good Eugene V. Koonin (2007). The cosmological model of eternal inflation and the transition from chance to biological evolution in the history of life. Biology Direct 2:15. web
Ingenius and beautiful.
Bad Eugene V. Koonin (2007). The biological Big Bang model for the major transitions in evolution. Biology Direct 2:21. web
Not impressing, too long, and has very little innovation.
Medium Bengt Sennblad & Jens Lagergren (2009). Probabilistic orthology analysis. Syst. Biol. 58:411-424. web
Read in part, gives a nice survey of their method, as well as other methods.
Medium Yuri I. Wolf & Eugene V. Koonin (2007). On the origin of the translation system and the genetic code in the RNA world by means of natural selection, exaptation, and subfunctionalization. Biology Direct 2:14. web
Cute, but way too long.
Ideas
Prominent people:
Abbreviations:
HGT
Horizontal gene transfer
Further topics: