Whether or not last universal common ancestor is even probable

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Summary: Last Universal Common Ancestor has been held to be the common ancestor of all the organisms that are known to exist on Earth. However, it is not correct and therefore ruled out. …

Summary: Last Universal Common Ancestor has been held to be the common ancestor of all the organisms that are known to exist on Earth. However, it is not correct and therefore ruled out.
Author: Dr Mahesh C. Jain is a practicing medical doctor and has written the book “Encounter of Science with Philosophy – A synthetic view”. The book begins with first chapter devoted to scientifically valid concept of God and then explains cosmic phenomena right from origin of nature and universe up to origin of life and evolution of man. The book includes several chapters devoted to auxiliary concepts and social sciences as corollaries to the concept of God. This is the only book which deals with origin of nature and universe from null. Twenty-ninth chapter of the book deals with the subject matter of ‘Origin of Life’.

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  • 1. Whether or Not Last Universal Common Ancestor Is Even ProbableSummary: Last Universal Common Ancestor has been held to be the commonancestor of all the organisms that are known to exist on Earth. However, it isnot correct and therefore ruled out.The idea of there being a Last Universal Common Ancestor (LUCA) also knownas Last Universal Ancestor (LUA) arose as a corollary to Charles Darwin’s theoryof evolution. It is also described as Most Recent Common Ancestor (MRCA) ofall current life on earth. Charles Darwin twice stated in his book ‘On the Originof Species’ about LUCA: “Therefore I should infer from analogy that probably all the organicbeings which have ever lived on this earth have descended from some oneprimordial form, into which life was first breathed” “There is grandeur in this view of life, with its several forms, having beenoriginally breathed into a few forms or into one”Scientific papers abound describing improbability of any other possibility aswell as features of LUCA. Wikipedia contains a list of 22 features of LUCA asreported in various scientific papers. As recent as 2010, Hesman Saey, T. inDiscovery News has claimed a very high improbability of any other possibilityon mathematical-logical basis.In 1998, Carl Woese proposed that no individual organism can be consideredas LUCA. He rather suggested community of organisms. In May 2010, Steel,Mike and Theobald, Douglas L. based on “vast array of molecular sequencesnow available from all domains of life” proposed a formal test of commonancestry. However, the formal test did not require LUCA to be single organism,but allowed it to be a population of organisms with different genotypes thatlived in different places and times. The formal test is also compatible withmultiple populations with independent origins (Ref. Wikipedia: Last UniversalCommon Ancestor).Distribution of life: Life is widely distributed on the surface of Earth, above thesurface of Earth and below the surface of Earth. Life has been reported to exist
  • 2. as much as 41 Km above the surface of Earth in atmosphere and 10 Km belowthe surface of Earth in deep oceans. Barophillic Marine microbes have beenfound at more than 10 Km depth in Marianas Trench. Culturable Thermophillicmicrobes have been extracted from cores drilled more than 5 Km into Earth’scrust in Sweden (Gold, 1992; and Szewzyk, 1994, both in PNAS). Life is knownto exist at temperatures as high as 122°C (Methanopyrus kandleri, Strain116).Life is known to occur in vastly different habitats and so life forms range fromextremophiles - capable of living in extreme environments to parasites capableof existence only in highly protected and specific environments provided bytheir host.The bottom line is that in order to keep existence, all life forms have to beeither well adapted or potentially adaptable to conditions of their existence.No life form can ever exist for even brief periods under conditions to which it isneither adapted nor adaptable.Therefore existence of LUCA means existence of an organism that was able tosurvive across the entire biosphere or exist in all habitats in which life ispresently known to occur.So far none of the biologists have addressed themselves this question.But on the basis of behavior of known life forms, it is hardly imaginable thatthere could have ever been an organism capable of surviving in all habitats thatconstitute biosphere.Alternatively, it may be said that Last Universal Common Ancestor, originatedat one or the other place and then gradually and over an immense period oftime dispersed to the entire biosphere. But such an eventuality in highlyimprobable, keeping in view inability of organisms to survive in environmentsto which they are neither adapted nor adaptable. Therefore it requireshysterical dissociation of beliefs to believe that entire biosphere came to bepopulated by the simple process of dispersal/migration of LUCA. Moreover if Last Universal Common Ancestor was capable of surviving acrossthe entire biosphere, than what was the drive to further evolution in the lightof Darwin’s Theory of evolution? Since, according to currently popular theoriesabout evolution, improved adaptation leading to success in survival struggle
  • 3. was the goal and objective of progressive evolution, with imperfect formstrying to perfect themselves.What is even more difficult to explain is migration of LUCA and its descendentsto a depth of 5 Km into Earth’s crust and vice-versa.Therefore, the so called LUCA is nothing but scientific fiction created to fill gapsin the theory, since rationally speaking, there can’t be a single organism thatcould exist across the entire biosphere or its descendents would be able topopulate the entire biosphere as they evolve.Hence LUCA is not even probable.Therefore life must have originated in all habitats in which it could possiblyoriginate, satisfying all the conditions mandatory to origin of life. No doubtthat these mandatory conditions are presently unknown or have not beenidentified.Author: Dr Mahesh C. Jain is a practicing medical doctor and has written thebook “Encounter of Science with Philosophy – A synthetic view”. The bookbegins with first chapter devoted to scientifically valid concept of God andthen explains cosmic phenomena right from origin of nature and universe upto origin of life and evolution of man. The book includes several chaptersdevoted to auxiliary concepts and social sciences as corollaries to the conceptof God. This is the only book which deals with origin of nature and universefrom null. Twenty-ninth chapter of the book deals with the subject matter of‘Origin of Life’.http://www.sciencengod.comhttp://www.sciencengod.com/buynow.php