Peter R. Bahn

Models for protocellular photophosphorylation

Several photoreactions for transducing light energy have been analyzed for their relevance as models for protocellular photophosphorylation. Inorganic ions and compounds could have played a role in protocellular photophosphorylation. Organic catalysts may have been the next significant agents used by protocells for photophosphorylation. Membranous photophosphorylation probably became the most recent type of photoenergy transduction to be acquired by protocells; it is still used by modern cells although components of the other types of phosphorylation are found in present day cells. Recorded yields of energy-rich phosphates from the model reactions discussed are small. Arguments are advanced that such yields could have been sufficient to have fueled protocellular metabolism which was probably very slow compared to modern cellular metabolism. Future prospects for research in this area are discussed.

Experimental Retracement of Terrestrial Origin of an Excitable Cell: Was it Predictable?

A largely historical treatment of how the evolutionary sequence to the first synthesis of life under terrestrial conditions, as retraced in the laboratory, is presented. The insights of such pioneers as Pasteur on self-organization of matter to “beings” are related. The recent acknowledgment of fruitless attempts by experts in DNA-first. RNA-first. and in irrelevance of the concept of random beginnings are cited. Updating of origins from amino acid-instructed genetically primary thermal protein is detailed. The essence of the finding of internal nonrandomness is emphasized, as well as the critical nature of studying the initial steps of molecular evolution in a synthetic direction. The total flowsheet for amino acid precursors ➔ protocell = protoneuron is updated. The results of experiments are tested against the characteristics of life as it is usually defined: metabolism, growth, reproduction, and response to stimuli such as light.

HPLC Evidence of Nonrandomness in Thermal Proteins

We believe that the first proteins to be synthesized on the Primitive Earth were thermal proteins. Thermal proteins were found by Sidney W. Fox and his colleagues to be nonrandom self-ordered copolyamino acids. HPLC supports this conclusion.

Visually Retracing the Emergence of the Evolvable Protocell

Seven thermal proteins and two of their dialyzed products were observed (oil-immersion light microscopy l, 000x @ 60° C) as they were moistened with 1.0% aqueous solutions of each of seven salts to yield protocells by self-assembly. The spherical protocells ranged in diameters from 0.1 to 10 µm, but formed two populations most commonly ∼ 0.5 and ∼ 3.0 µm. The small protocellular population was first visible within 30 sec and the larger protocells formed about 30 sec to 4 min. later. Both populations increased slightly in diameter within the following 15–30 min.

The Tangled Tree: a Radical New History of Life by David Quammen, Simon & Schuster, 2018

It was a desire to learn more about the legendary scientist Carl Woese that led me to read David Quammen’s book The Tangled Tree. Woese was a professor of microbiology at the University of Illinois who was responsible for causing a revolution in our view of the Tree of Life in the late 20th – early twenty-first Century. In his book describing this tree, Quammen has written a splendid history of what is now known as the field of molecular phylogenetics, the study of how biological organisms are related to each other based on looking at the similarities of their nucleotide base sequences in analogous genes of the organisms under study. This vividly written tale of the Tree begins with Charles Darwin who first drew in his notes for his grand book The Origin of Species a picture of a stick-figure tree to represent the branching of species from a single root over time. When it was realized that cells come in only two types, those cells without a nucleus and those cells with a nucleus, it was thought thereafter for most of the twentieth Century that the Tree of Life contained only two Kingdoms, the Prokarya (cells without a nucleus) and the Eukarya (cells with a nucleus). With the advent of molecular genetics starting in the 1950s and 1960s, Woese, a theoretical biophysicist, sought to compare the relatedness of various organisms by studying the RNA sequences of their 16S ribosomal RNA. In the process of doing this work, Woese was greatly aided by his experimentalist colleague George Fox, who carried on Woese’s work after his death in 2012. By looking at 16S rRNA sequences of various cells without nuclei called methanogens and various cells without nuclei called extremophiles (because they live under physically harsh conditions), Woese realized that a third Kindom of life existed which was singularly different from the known prokarotes (mostly bacteria) and the known eukaryotes (mostly complex plant and animal cells). To this third kingdom of life on Earth Woese gave the name Archaea reflecting this kingdom’s archaic nature. Archaea are an extraordinarily primitive group of single celled organisms, some of which thrive in the extremely hot waters of hydrothermal vents and which feed on the vents’ hydrogen sulfide. Not only do the genes of Origins of Life and Evolution of Biospheres https://doi.org/10.1007/s11084-018-9566-5

A Grand Introduction to the Biomineral World

If you read magazines, you may have come across advertisements for The Great Courses® offering at reasonable prices DVD lectures on everything from travel photography to California wines. One such ad which caught my attention recently was for the subject of this DVD Review. I met Bob Hazen, a friendly energetic guy, in 2005 at an astrobiology conference and a Gordon conference. I read his 2005 book entitled Biogenesis: The Scientific Quest for Life’s Origin and wrote a favorable review on it for OLEB. Shortly before watching the DVD course reviewed herein, I watched Hazen’s 2005 DVD Great Course® entitled Origins of Life and found that to be excellent. As a matter of background information to this lecturer, Robert Hazen received a B.S. degree in geology from MIT and a Ph.D. degree in mineralogy from Harvard. He did research in pure mineralogy before turning his attention a decade and a half ago to the origins of life problem at the suggestion of Harold Morowitz. Hazen and Morowitz currently are professors at George Mason University. Since then, Hazen has done significant research in modeling possible prebiotic high temperature and high pressure syntheses of biomolecules such as the kind which might have taken place at hydrothermal vents or below hydrothermal vents in the Earth’s mantle. In addition to being the Clarence J. Robinson Professor of Earth Sciences at George Mason University, Hazen also is a Senior Staff Scientist at the Carnegie Institution’s Geophysical Laboratory in Washington, D.C. and the founding Executive Director of the Sloane Foundation’s Deep Carbon Observatory project. The settings of these 48 half hour lectures is a geologist’s study with a microscope and rocks much like a kind of den that one could imagine serving as a base for a geologist such as James Hutton or Charles Lyell. Among the wood-paneled walls of this study, Hazen gives his audience a lecture performance that is one of the best that I have ever seen. Hazen knows his material so well that he delivers all of his lectures entirely without notes. In his lectures, Hazen is doing simultaneously, as a great lecturer must, a number of things: He is telling a grand epic story of how, with innumerable circumstances developing within deep space and deep time since the Big Bang approximately 14 billion years ago, dust grew to form rocks which grew to DOI 10.1007/s11084-014-9376-3

Life in the Universe: A Beginner’s Guide

Lewis Dartnell tells us in his introduction that as he writes, he occasionally gazes at an ecosphere sitting on his desk. An ecosphere is a completely enclosed glass “world” containing an atmosphere (at least initially) of air, half the sphere being filled with water containing seaweed and small forms of animal life. Although the ecosphere can receive heat and light from the outside world, it is in almost all other respects a sealed world unto itself. Dartnell pauses at times to contemplate all of the interesting changes that could be going on inside the ecosphere. This pondering about the glass-enclosed ecosphere is a symbol for his book, for its subject is the nature of the Universe and the life that is evolving within it, especially on our home planet Earth. The book covers an enormous breadth of subject matter but nevertheless somehow manages to be readable, understandable and accurate at the same time. In the first chapters, Dartnell explores the definition and the outer physical limits of life as we know it. Then the author discusses how cosmic evolution leads to nuclear stellar synthesis, the generation of solar systems, accretion of planets, and the origin of life on Earth. In the last part of his book, Dartnell gives a kaleidoscopic tour of our Solar System and beyond where we might find extraterrestrial life. In the concluding chapter, entitled ‘Synthesis’ Dartnell gives rein to his imagination, tempered as it is by being the imagination of a scientist, as to what an intelligent alien might look like if we human beings ever encounter one. I am almost tempted as a reviewer to quote the last paragraph of this chapter which describes the intelligent alien that Dartnell conjures up, but I will leave that pleasant surprise to the readers of this excellent book. I enjoyed reading Life in the Universe: A Beginner’s Guide very much. It seemed to hit all of the important points and questions in a straightforward manner without being prejudicial about what the answers are. This is good, considering that we have yet to find out how life originated and that we don’t know if there is life anywhere else in the Universe. Orig Life Evol Biosph (2008) 38:193–194 DOI 10.1007/s11084-007-9116-z

Robert M. Hazen: Genesis: The Scientific Quest for Life’s Origin

It is people who become scientists and not scientists who become people. Kepler was a religiously trained mathematician who somehow survived the Thirty Years War and who cast horoscopes to make ends meet. Galileo was a devout Roman Catholic who became an astronomer, but he spent about half his time being a courtier to Medician princes and other such patrons. Newton was an academic scholar of unparalleled brilliance who became a theoretical physicist, in addition to being an alchemist and religious writer, but he was a somewhat paranoid and vindictive man who sometimes enjoyed destroying the reputations of other scientists. Einstein was a great and noble scientific sage, but he was certainly not much of a family man. James Watson, who for sure possessed a brilliant mind, could also, disturbingly, lower himself to search through Rosalind Franklin’s desk for DNA data when she was out of her office, as he describes in his brutally honest memoir The Double Helix. Who are kind of people that become origin-of-life (OOL) scientists? The author of this fascinating book reveals some answers to this question by providing the reader with a series of roving eye and ear portraits of some of the leading scientists in OOL research as they go about their daily activities. Included in this volume are very interesting accounts of, among others, scientists such as: Harold Morowitz, J. William Schopf, Martin Brasier, Marilyn Fogel, Stanley Miller, John Corliss, David Deamer, Gunter Wactershauser, Jack Szostak, Leslie Orgel, Gustaf Arrhenius, James Ferris, Graham Cairns-Smith, Reza Ghadiri, Stuart Kauffman, Sidney Fox, Christian de Duve, Sol Spiegelman, and Gerald Joyce. I do not want to reveal what Bob Hazen says in this book about such a varied array of scientific personalities. Let that be a surprise to the readers of this excellent account of what it feels like to be an OOL scientist, and a study of what kind of people become such scientists, and how such people act in their respective roles as scientists. However, what kind of person is the scientist who penned this account of OOL scientists in the first place? Bob Hazen is a friendly and energetic fellow who holds joint appointments as a research scientist at the Carnegie Institution of Washington and as a professor at George Mason University. Most interestingly, Hazen is also a professional trumpeter who plays this instrument in the National Philharmonic Orchestra, the National Orig Life Evol Biosph (2007) 37:205–206 DOI 10.1007/s11084-006-9025-6

Life as We Do Not Know It: The NASA Search for (and Synthesis of) Alien Life

I was sitting in the audience at AbSciCon 2006 in Washington, DC, when Peter Ward, and a moderator and four distinguished panelists met to publicly discuss Peter Ward’s new book Life as We Do Not Know It. We astrobiologists are already in debt to Ward (and his coauthor Donald Brownlee) for writing the instant classic Rare Earth: Why Complex Life is Rare in the Universe. What followed, for the next two hours, was one of the most entertaining evenings I have ever spent, enthralled as I was by the twists and turns of a remarkable and sometimes funny discussion. Near the beginning of the panel discussion, Ward stated something to the effect that people’s definitions of life differ with respect to even Life as We Know It. To illustrate, Ward asked those individuals in the audience to raise their hands if they considered viruses to be alive (About 60% raised their hands). Next, Ward asked those in individuals in the audience to raise their hands if they did not consider viruses to be alive (about 40%, I among them, raised their hands). One person in the balcony had the comic audacity to yell out, “How about a show of hands for those who couldn’t care less, either way!” At this point Ward affected an expression of mock outrage on his face that was extremely funny, thereby doubling the audience laughter. The main import of the panel discussion was that none of the panelists and Ward could agree on a common definition of Life as We Know It, let alone trying to define Life as We Do Not Know It. Each of the panelists saw essential things differently. When the discussion was opened up to input from members of the audience, it was apparent, too, that neither could all of these astrobiologists, with their different specialties, agree on a common definition of Life. I eventually began to see that how a scientist defines Life is largely a product of his or her philosophical approach to existence itself. For example, I realized that one of my friends in the audience approached both existence and defining Life from a Kirkegaardian point of view. Ward is a questioner, and in his sometimes playful book, he poses many interesting questions and propositions for the reader, involving the ins and outs of Life, and what we can agree on and what we seem to have trouble agreeing on. Ward seems incapable of writing Orig Life Evol Biosph (2007) 37:207–208 DOI 10.1007/s11084-006-9023-8

Determinism and the Proteinoid Theory

The discovery of proteinoids (thermal proteins; branched proteins) in the 1950s and protocells there from, filled the gap between physical/chemical and biological evolution. The ease in finding amino acids in nature for the autocatalytic synthesis of branched proteins (self-ordering) and the ease of finding water in which these macromolecules would form protocells (self-assembly) made the proteinoid theory appealing for those interested in finding a model for the synthesis of living cells (Fox, 1988) and those seeking a candidate system for the origin and early evolution of life (Pappelis, et al., 2001). We worked with Sidney W. Fox and his associates. Together with Fox, we moved his “model” into biology as the branched protein-first paradigm to explain the origin of chemical and biological life. We inferred the pathways in the early evolution of protolife to provide new opportunities for experimental verification.