Chapter category: Evolution
The Early Earth
The Genetic Code and the Origin of Life
Edited by: Lluis Ribas de PouplanaISBN: 0-306-47843-9
» Get more information about this book at landesbioscience.com «
Chapter authors:
Oliver Botta and Jeffrey L. Bada
The Earth is so far the only place in the Universe where life is known to exist. Is the Earth special, or are there other places both in our own solar system and beyond where life may have originated and either became extinct or still exists today? Hopefully, in the not to distant future we may find out. During the coming decades, spacecraft will search for evidence of life on Mars and Jupiter’s moon Europa, which are considered to be the most promising places for the existence of extant or extinct extraterrestrial life within our solar system. Using remote sensing techniques, we will also begin to look for signs of life’s chemistry on the extrasolar planets, which seem to be omnipresent companions of many main sequence stars. If the conditions that resulted in the origin of life on Earth are common throughout the Universe, it seems almost certain that life must exist elsewhere. However, to evaluate whether the Earth is a unique place, or simply an average rocky planet around an average star, we must access what the Earth was like before life began and how these conditions contributed to the processes thought to be involved in the origin of life.
Additional chapters from this book:
The Evolutionary History of the Translation Machinery
George E. Fox and Ashwinikumar K. Naik
Current theories on the origin of life envision an RNA World as the culmination of chemical evolution. The extent of this RNA World, and the biochemical complexity of the progenotes1 that populated ...
Adaptive Evolution of the Genetic Code
R.D. Knight, S. J. Freeland and L.F. Landweber
All known genetic codes use 4 bases and 20 amino acids, but many other bases and amino acids have been synthesized and/or found in organisms. The coding relation ships between particular trinucleoti...
Ribozyme-Catalyzed Genetics
Donald H. Burke
RNA World research in recent years has sought to establish whether ribozymes have the catalytic versatility and potency to transmit genetic information and to sustain a credible metabolism. At a min...
The Nature of the Last Common Ancestor
Luis Delaye, Arturo Becerra, and Antonio Lazcano
Until the late 1970’s cellular evolution was assumed to be a continuous, unbroken chain of progressive transformations that begun with the emergence of life itself and contin ued until the endosymbi...
Extant Variations in the Genetic Code
Manuel A.S. Santos and Mick F. Tuite
The discovery in the 1960s of an identical genetic code in Escherichia coli, viruses and mammalian cells suggested that all living organisms use the same genetic code. The existence of a universal g...
Functional Evolution of Ribosomes
C. Briones and R. Amils
Protein synthesis is a complex process that constitutes the last step of gene expression. The first studies that correlated this cellular activity with certain “ribonucleoprotein par ticles” present...
Expanding the Genetic Code in Vitroand in Vivo
Thomas J. Magliery and David R. Liu
Insight into biological function at almost every level, from catalysis to signal transductionto structure, requires a detailed understanding of proteins, biopolymers of remarkable di-versity assembled...
Origin and Evolution of DNA and DNA Replication Machineries
Patrick Forterre, Jonathan Filée and Hannu Myllykallio
The transition from the RNA to the DNA world was a major event in the history of life. The invention of DNA required the appearance of enzymatic activities for both synthe- sis of DNA precursors,...
Early Evolution of DNA Repair Mechanisms
Jocelyne DiRuggiero and Frank T. Robb
DNA repair is critical for the maintenance of genome integrity and replication fidelity in all cells, and therefore was arguably of major importance in the Last Universal Cellular Ancestor (LUCA...
The Early Earth
Oliver Botta and Jeffrey L. Bada
The Earth is so far the only place in the Universe where life is known to exist. Is the Earth special, or are there other places both in our own solar system and beyond where life may have origi...
Reconstructing the Universal Tree of Life
James R. Brown
The universal tree of life depicts the evolutionary relationships of all living things by grouping them into one of three Domains of life; the Archaea (archaebacteria), Bacteria (eubacteria) and ...
The Scope of Selection
Michael Yarus and Rob Knight
We have estimated the maximal size for an RNA motif recoverable from selection-amplification for new RNA activities, under conditions that span those in present laboratory use. The number of s...
