Development of the Hypotheses for the Biochemical Origin of Life

2021 ◽  
Vol 30 (3) ◽  
pp. 305-316
Author(s):  
Zdravka Kostova ◽  
Keyword(s):  
Origin Of Life ◽  
Common Ancestor ◽  
Natural Sciences ◽  
Biochemical Processes ◽  
Geochemical Conditions ◽  
Living Things ◽  
Universal Common Ancestor ◽  
Basic Characteristics

Analyzes the main positions and critiques of leading hypotheses about the biochemical origin of life as a result of new achievements in natural sciences and technologies. Compares their basic characteristics in respect to proposed geochemical conditions and argued consequences of biochemical processes. Gives description of the last common universal common ancestor of all living things – LUCA.

scholarly journals Origin of Life

2021 ◽  
Vol 83 (2) ◽  
pp. 76-79
Author(s):  
Cristina Sousa
Keyword(s):  
Origin Of Life ◽  
Common Ancestor ◽  
Scientific Evidence ◽  
Recent Common Ancestor ◽  
Last Universal Common Ancestor ◽  
Most Recent Common Ancestor ◽  
Universal Common Ancestor ◽  
The Origin Of Life

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.

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

2016 ◽  
Vol 16 (2) ◽  
pp. 105-113 ◽  
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 ◽  
Last Universal Common Ancestor ◽  
Universal Common Ancestor ◽  
The Origin Of Life

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.

The Origin of a New Kind of Science From the Life Sciences

2020 ◽  
Vol 30 (1) ◽  
pp. 131-158
Keyword(s):  
Natural Philosophy ◽  
Human Life ◽  
Natural Sciences ◽  
Natural Phenomenon ◽  
Dominican Order ◽  
Cultural Traditions ◽  
Knowledge Based ◽  
Living Things ◽  
Theoretical Morphology ◽  
Living Nature

Science in the modern era began with a process of synthesis; the natural sciences in particular emerged through a coalescence of several cultural traditions. Scientific knowledge arose in a series of several separate events as mathematics, philology, physics and biology emerged independently. Scientific ideas about natural life developed via a synthesis of three types of knowledge. (1) There was the tradition of herbalism as a type of knowledge of nature, and this approach remained close to the Aristotelian tradition of describing nature with a bookish method centered on descriptive practice. (2) The scholastic tradition clarified existing concepts and formed new ones. Its role was crucial in supplying nascent science with its set of cognitive tools. (3) The alchemical tradition provided experimental knowledge of nature as applied to human life. It was particularly important in building the skills needed to connect theoretical systems with reality. This synthesis in natural philosophy was the basis of Linnaean reforms. However, theoretical morphology was cen¬tral to Linnaeus’ thinking and, its features were responsible for the success of his system. Theoretical morphology offered ways to decide how a natural phenomenon should be reduced and divided into parts in order to serve as an object of scientific cognition. Essential theoretical precepts for this morphology were formulated by Andrea Cesalpino in De plantis libri XVI (1583). Hence, the origin of the natural sciences as a study of living nature should properly be traced to the 16th century. This strand in the development of the new scientific approach in Europe through studying living things should also be connected with earlier (medieval) efforts of the Dominican Order (promoting purer versions of Aristotelianism), while another strand which led to the appearance of physics and other more mathematically expressed branches of the natural sciences belongs to the Franciscan orders (more influenced by Neoplatonism). Science emerged then as profound and experimentally verifiable theoretical knowledge based on ideation through the construction of the objects of experimental research.

scholarly journals SepF is the FtsZ anchor in archaea, with features of an ancestral cell division system

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Nika Pende ◽  
Adrià Sogues ◽  
Daniela Megrian ◽  
Anna Sartori-Rupp ◽  
Patrick England ◽  
...  
Keyword(s):  
Cell Division ◽  
Common Ancestor ◽  
Phylogenetic Analyses ◽  
Super Resolution ◽  
Binding Mode ◽  
Last Universal Common Ancestor ◽  
Division Plane ◽  
Multiple Factors ◽  
Universal Common Ancestor ◽  
Super Resolution Microscopy

AbstractMost archaea divide by binary fission using an FtsZ-based system similar to that of bacteria, but they lack many of the divisome components described in model bacterial organisms. Notably, among the multiple factors that tether FtsZ to the membrane during bacterial cell constriction, archaea only possess SepF-like homologs. Here, we combine structural, cellular, and evolutionary analyses to demonstrate that SepF is the FtsZ anchor in the human-associated archaeon Methanobrevibacter smithii. 3D super-resolution microscopy and quantitative analysis of immunolabeled cells show that SepF transiently co-localizes with FtsZ at the septum and possibly primes the future division plane. M. smithii SepF binds to membranes and to FtsZ, inducing filament bundling. High-resolution crystal structures of archaeal SepF alone and in complex with the FtsZ C-terminal domain (FtsZCTD) reveal that SepF forms a dimer with a homodimerization interface driving a binding mode that is different from that previously reported in bacteria. Phylogenetic analyses of SepF and FtsZ from bacteria and archaea indicate that the two proteins may date back to the Last Universal Common Ancestor (LUCA), and we speculate that the archaeal mode of SepF/FtsZ interaction might reflect an ancestral feature. Our results provide insights into the mechanisms of archaeal cell division and pave the way for a better understanding of the processes underlying the divide between the two prokaryotic domains.

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