Is it Possible that Cells have had More than One Origin?

Cellular Life ◽

Life Itself ◽

History Of ◽

Translation Mechanism ◽

Cells occupy a prominent place in the history of life on planet Earth. The central role of cellular organization is observed by the fact that “cellular life” is often used as a synonym for life itself. Thus, most characteristics used to define cells overlap with the ones used to define life. Notwithstanding, new scenarios about the origin of life are bringing alternative views to describe how cells may have evolved from the open biological systems named progenotes. Here, using a logical and conceptual analysis, we re-evaluate the characteristics used to infer a single origin for cells. We argue that some evidences used to support cell monophyly, such as the presence of elements from both the translation mechanism and the universality of the genetic code, actually indicate a unique origin for all “biological systems”, a term used to define not only cells, but also virus and progenotes. Besides, we present evidence that at least two biochemical pathways as important as (i) DNA replication and (ii) lipid biosynthesis may not homologous between Bacteria and Archaea. The identities observed between the proteins involved in those pathways along representatives of these two ancestral Domains are too low to indicate common genic ancestry. Altogether these facts can be seen as an indication that cellular organization has possibly evolved two or more times and that LUCA (the Last Universal Common Ancestor) might not have existed as a cellular entity. Thus, we aim to consider the possibility that different strategies acquired by biological systems to exist, such as viral, bacterial and archaeal were originated independently from the evolution of different progenote populations.

Origin of life: LUCA and extracellular membrane vesicles (EMVs)

International Journal of Astrobiology ◽

10.1017/s1473550415000282 ◽

2015 ◽

Vol 15 (1) ◽

pp. 7-15 ◽

Cited By ~ 8

Author(s):

S. Gill ◽

P. Forterre

Keyword(s):

Common Ancestor ◽

Membrane Vesicles ◽

Molecular Systems ◽

Cellular Physiology ◽

Cellular Life ◽

Domains Of Life ◽

Metabolic Reactions

AbstractCells from the three domains of life produce extracellular membrane vesicles (EMVs), suggesting that EMV production is an important aspect of cellular physiology. EMVs have been implicated in many aspects of cellular life in all domains, including stress response, toxicity against competing strains, pathogenicity, detoxification and resistance against viral attack. These EMVs represent an important mode of inter-cellular communication by serving as vehicles for transfer of DNA, RNA, proteins and lipids between cells. Here, we review recent progress in the understanding of EMV biology and their various roles. We focus on the role of membrane vesicles in early cellular evolution and how they would have helped shape the nature of the last universal common ancestor. A membrane-protected micro-environment would have been a key to the survival of spontaneous molecular systems and efficient metabolic reactions. Interestingly, the morphology of EMVs is strongly reminiscent of the morphology of some virions. It is thus tempting to make a link between the origin of the first protocell via the formation of vesicles and the origin of viruses.

Be Introduced to the First Universal Common Ancestor (FUCA): The Great-Grandmother of LUCA (Last Universal Common Ancestor)

10.20944/preprints201806.0035.v1 ◽

2018 ◽

Cited By ~ 2

Author(s):

Francisco Prosdocimi ◽

Marco V José ◽

Sávio Torres de Farias

Keyword(s):

Common Ancestor ◽

Rna World ◽

Biological Systems ◽

Translation System ◽

Domains Of Life ◽

Translation Mechanism ◽

Living Organisms ◽

Definition Of

The existence of a common ancestor to all living organisms in Earth is a necessary corollary of Darwin idea of common ancestry. The Last Universal Common Ancestor (LUCA) has been normally considered as the ancestor of cellular organisms that originated the three domains of life: Bacteria, Archaea and Eukarya. Recent studies about the nature of LUCA indicate that this first organism should present hundreds of genes and a complex metabolism. Trying to bring another of Darwin ideas into the origins of life discussion, we went back into the prebiotic chemistry trying to understand how LUCA could be originated under gradualist assumptions. Along this line of reasoning, it became clear to us that the definition of another ancestral should be of particular relevance to the understanding about the emergence of biological systems. Together with the view of biology as a language for chemical translation, on which proteins are encoded into nucleic acids polymers, we glimpse a point in the deep past on which this Translation mechanism could have taken place. Thus, we propose the emergence of this process shared by all biological systems as a point of interest and propose the existence of this non-cellular entity named FUCA, as the First Universal Common Ancestor. FUCA was born in the very instant on which RNA-world replicators started to be capable to catalyze the bonding of amino acids into oligopeptides. FUCA has been considered mature when the translation system apparatus has been assembled together with the establishment of a primeval, possibly error-prone genetic code. This is FUCA, the great-grandmother of LUCA.

Origin of Life

The American Biology Teacher ◽

10.1525/abt.2021.83.2.76 ◽

2021 ◽

Vol 83 (2) ◽

pp. 76-79

Author(s):

Cristina Sousa

Keyword(s):

Origin Of Life ◽

Common Ancestor ◽

Scientific Evidence ◽

Recent Common Ancestor ◽

Most Recent Common Ancestor ◽

The origin of life is one of the most interesting and challenging questions in biology. This article discusses relevant contemporary theories and hypotheses about the origin of life, recent scientific evidence supporting them, and the main contributions of several scientists of different nationalities and specialties in different disciplines. Also discussed are several ideas about the characteristics of the most recent common ancestor, also called the “last universal common ancestor” (or LUCA), including cellular status (unicellular or community) and homogeneity level.

The origin of life and the last universal common ancestor: do we need a change of perspective?

Research in Microbiology ◽

10.1016/j.resmic.2009.05.003 ◽

2009 ◽

Vol 160 (7) ◽

pp. 522-528 ◽

Cited By ~ 20

Author(s):

Nicolas Glansdorff ◽

Ying Xu ◽

Bernard Labedan

Keyword(s):

Origin Of Life ◽

Common Ancestor ◽

Change Of Perspective ◽

Perbandingan Kurikulum Pendidikan Sejarah di Rusia dan Indonesia

Jurnal Pendidikan Sejarah ◽

10.21009/jps.041.04 ◽

2017 ◽

Vol 4 (1) ◽

pp. 44

Author(s):

Jumardi Jumardi

Keyword(s):

Human Life ◽

History Teaching ◽

Models Of Teaching ◽

Teaching History ◽

Russian State ◽

Life Itself ◽

History Of ◽

Teaching Curriculum ◽

Spiral Model

Learning of history very real associated with human life itself. Learning the history of studying thehuman role in the nation’s history and history itself . Learning curriculum history becomes important instudying the role of every human being . This should be reviewed when learning materials and learningoutcomes are not proportional . The educational system of a country determines how a curriculum isapplied to all subjects . Comparing a learning curriculum Indonesian history becomes necessary to obtaina picture of how the teaching of history in Indonesia and the Russian State history teaching curriculum. Models of teaching history in Indonesia using the spiral model ( repetition ) while Russia using linearmodels . Learners and citizens of Russia have the pride of the history of his country.

"Life itself acquainted me with and made me become an intimate friend of language…" (to the V. I. Dal’s 220th anniversary of the birth)

Russian language at school ◽

10.30515/0131-6141-2021-82-5-91-98 ◽

2021 ◽

Vol 82 (5) ◽

pp. 91-98

Author(s):

M. N. Priemysheva

Keyword(s):

Short Review ◽

Russian Language ◽

Professional Activity ◽

Scientific Discussion ◽

Life Itself ◽

Birthday Anniversary ◽

History Of ◽

Creative Experience ◽

Educational Potential

This paper devoted to V. I. Dal’s 220th birthday anniversary presents a short review of his creative, professional activity in the context of compiling "The Explanatory Dictionary of the Living Great Russian Language". Being exemplified by a brief scientific discussion which dates back to the end of the XIXth century, the role of this Dictionary in the history of the academic explanatory lexicography development is highlighted in greater detail. The aim of the study was to generalise the well-known facts about V. I. Dal and his Dictionary as well as to refer to lesser-known sources. V. I. Dal contributed significantly to each of the spheres in which he was creatively or professionally involved: he was a naval officer, a doctor, a writer, and a civil servant of the Ministry of Internal Affairs. All Dal’s professional and creative experience as well as his in-depth knowledge of folklife had an impact on the structure, form, and content of the Dictionary: they made it the yardstick and exemplar of Russian lexicography. This thesis is expounded in the course of studying I. Kh. Pachmann’s critical "Memorandum" (1899) concerning the commencement of the work on the "Shakhmatov’s revision" of the academic "Dictionary of the Russian Language". Additionally, this "Memorandum" provides certain evaluation of Dal’s edition from the perspective of its educational potential that could be exploited in school education. Despite the drawbacks revealed by his contemporaries, V. I. Dal’s dictionary inadvertently became the yardstick and exemplar in the discussion of the moot issues arising during the initiation of the new academic project. It is this dictionary that influenced the further development of explanatory academic lexicography.

Buds of the tree: the highway to the last universal common ancestor

International Journal of Astrobiology ◽

10.1017/s147355041600029x ◽

2016 ◽

Vol 16 (2) ◽

pp. 105-113 ◽

Cited By ~ 3

Author(s):

Savio Torres de Farias ◽

Francisco Prosdocimi

Keyword(s):

Origin Of Life ◽

Common Ancestor ◽

Rna World ◽

Biological Activities ◽

Ribosomal Subunit ◽

Life Forms ◽

Point Of View ◽

AbstractThe last universal common ancestor (LUCA) has been considered as the branching point on which Bacteria, Archaea and Eukaryotes have diverged. However, the increased information relating to viruses’ genomes and the perception that many virus genes do not have homologs in other organisms opened a new discussion. Based on these facts, there has emerged the idea of an early LUCA that should be moved further into the past to include viruses, implicating that life should have originated before the appearance of cellular life forms. Another point of view from advocates of the RNA-world suggests that the origin of life happened a long time before organisms were capable of organizing themselves into cellular entities. Relevant data about the origin of ribosomes indicate that the catalytic unit of the large ribosomal subunit is what should actually be considered as the turning point that separated chemistry from biology. Other researchers seem to think that a tRNA was probably some sort of a strange attractor on which life has originated. Here we propose a theoretical synthesis that tries to provide a crosstalk among the theories and define important points on which the origin of life could have been originated and made more complex, taking into account gradualist assumptions. Thus, discussions involving the origin of biological activities in the RNA-world might lead into a world of progenotes on which viruses have been taken part until the appearance of the very first cells. Along this route of complexification, we identified some key points on which researchers may consider life as an emerging principle.

Terpenes, hormones and life: isoprene rule revisited

Journal of Endocrinology ◽

10.1530/joe-19-0084 ◽

2019 ◽

Vol 242 (2) ◽

pp. R9-R22 ◽

Cited By ~ 8

Author(s):

Stephen G Hillier ◽

Richard Lathe

Keyword(s):

Characteristic Number ◽

Cellular Membrane ◽

Molecular Structures ◽

Evolutionary Perspective ◽

80Th Anniversary ◽

Cellular Life ◽

Male Sex ◽

The Origin Of Life ◽

And Function

The year 2019 marks the 80th anniversary of the 1939 Nobel Prize in Chemistry awarded to Leopold Ruzicka (1887–1976) for work on higher terpene molecular structures, including the first chemical synthesis of male sex hormones. Arguably his crowning achievement was the ‘biogenetic isoprene rule’, which helped to unravel the complexities of terpenoid biosynthesis. The rule declares terpenoids to be enzymatically cyclized products of substrate alkene chains containing a characteristic number of linear, head-to-tail condensed, C5 isoprene units. The number of repeat isoprene units dictates the type of terpene produced (i.e., 2, monoterpene; 3, sesquiterpene; 4, diterpene, etc.). In the case of triterpenes, six C5 isoprene units combine into C30 squalene, which is cyclized into one of the signature carbon skeletons from which myriad downstream triterpenoid structures are derived, including sterols and steroids. Ruzicka also had a keen interest in the origin of life, but the pivotal role of terpenoids has generally been overshadowed by nucleobases, amino acids, and sugars. To redress the balance, we provide a historical and evolutionary perspective. We address the potential abiotic generation of isoprene, the crucial role that polyprene terpenoids played in early membranes and cellular life, and emphasize that endocrinology from microbes to plants and vertebrates is firmly grounded on Ruzicka’s pivotal insights into the structure and function of terpenes. A harmonizing feature is that all known lifeforms (including bacteria) biosynthesize triterpenoid substances that are essential for cellular membrane formation and function, from which signaling molecules such as steroid hormones and cognate receptors are likely to have evolved.

Energy at Origins: Favorable Thermodynamics of Biosynthetic Reactions in the Last Universal Common Ancestor (LUCA)

Frontiers in Microbiology ◽

10.3389/fmicb.2021.793664 ◽

2021 ◽

Vol 12 ◽

Author(s):

Jessica L. E. Wimmer ◽

Joana C. Xavier ◽

Andrey d. N. Vieira ◽

Delfina P. H. Pereira ◽

Jacqueline Leidner ◽

...

Keyword(s):

Common Ancestor ◽

Atp Hydrolysis ◽

Uv Light ◽

Chemical Constituents ◽

Ring Closure ◽

External Energy ◽

Energy Inputs ◽

Life Itself

Though all theories for the origin of life require a source of energy to promote primordial chemical reactions, the nature of energy that drove the emergence of metabolism at origins is still debated. We reasoned that evidence for the nature of energy at origins should be preserved in the biochemical reactions of life itself, whereby changes in free energy, ΔG, which determine whether a reaction can go forward or not, should help specify the source. By calculating values of ΔG across the conserved and universal core of 402 individual reactions that synthesize amino acids, nucleotides and cofactors from H2, CO2, NH3, H2S and phosphate in modern cells, we find that 95–97% of these reactions are exergonic (ΔG ≤ 0 kJ⋅mol−1) at pH 7-10 and 80-100°C under nonequilibrium conditions with H2 replacing biochemical reductants. While 23% of the core’s reactions involve ATP hydrolysis, 77% are ATP-independent, thermodynamically driven by ΔG of reactions involving carbon bonds. We identified 174 reactions that are exergonic by –20 to –300 kJ⋅mol−1 at pH 9 and 80°C and that fall into ten reaction types: six pterin dependent alkyl or acyl transfers, ten S-adenosylmethionine dependent alkyl transfers, four acyl phosphate hydrolyses, 14 thioester hydrolyses, 30 decarboxylations, 35 ring closure reactions, 31 aromatic ring formations, and 44 carbon reductions by reduced nicotinamide, flavins, ferredoxin, or formate. The 402 reactions of the biosynthetic core trace to the last universal common ancestor (LUCA), and reveal that synthesis of LUCA’s chemical constituents required no external energy inputs such as electric discharge, UV-light or phosphide minerals. The biosynthetic reactions of LUCA uncover a natural thermodynamic tendency of metabolism to unfold from energy released by reactions of H2, CO2, NH3, H2S, and phosphate.

Reconstructing gene content in the last common ancestor of cellular life: is it possible, should it be done, and are we making any progress?

10.1101/013326 ◽

2014 ◽

Author(s):

Arcady Mushegian

Keyword(s):

Evolutionary Biology ◽

Common Ancestor ◽

Recent Literature ◽

Last Common Ancestor ◽

Gene Repertoire ◽

Ancestral State ◽

Cellular Life ◽

Life On Earth

I review recent literature on the reconstruction of gene repertoire of the Last Universal Common Ancestor of cellular life (LUCA). The form of the phylogenetic record of cellular life on Earth is important to know in order to reconstruct any ancestral state; therefore I also discuss the emerging understanding that this record does not take the form of a tree. I argue that despite this, “tree-thinking” remains an essential component in evolutionary thinking and that “pattern pluralism” in evolutionary biology can be only epistemological, but not ontological.