Cause of Cambrian Explosion - Terrestrial Or Cosmic?
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Cephalobus Litoralis: Biology and Tolerance to Desiccation
Journal of Nematology 20(2):327-329. 1988. © The Society of Nematologists 1988. Cephalobus litorali . Biology and Tolerance to Desiccation M. SAEED, S. A. KHAN, V. A. SAEED, AND H. A. KHAN1 Abstract: Cephalobus litoralis (Akhtar, 1962) Andr~ssy, 1984 reproduced parthenogenetically and completed its life cycle in 72-90 hours. Each female deposited 200-300 eggs. The nematodes showed synchronized movements in the rhythms of the anterior parts of the body. The nematodes were coiled when dried in culture medium or in slowly evaporating water droplets on the tops of culture plates, but in pellets they assumed irregular postures. Nematodes in pellets stored at high humidity could be reactivated after storage for 28 days. Key words: behavior, Cephalobus litoralis, coiling, desiccation tolerance, life cycle, parthenogenesis, synchronized movement. Cephalobus litoralis (Akhtar) Andrfissy, by a modified Baermann funnel method. 1984 was described in 1962 by Akhtar (1) A single gravid female was placed in a cav- as Paracephalobus litoralis based on only two ity slide containing water. After oviposi- female specimens collected from soil tion, a single egg was transferred to a petri around the roots of sugarcane (Saccharum dish containing finely blended pea meal o~cinarum L.) in the agricultural farms of paste (PMP) and water. All experiments the Pakistan Council of Scientific and In- were conducted with nematodes from sin- dustrial Research (PCSIR), Lahore, Paki- gle egg progeny raised in this manner. stan. It had not been reported elsewhere For mass rearing, nematodes were cul- until the authors found it in Karachi. In tured in 14-cm-d petri dishes containing 1967 Andrfissy (3) transferred Eucephalo- pea meal paste. -
Modelling Panspermia in the TRAPPIST-1 System
October 13, 2017 Modelling panspermia in the TRAPPIST-1 system James A. Blake1,2*, David J. Armstrong1,2, Dimitri Veras1,2 Abstract The recent ground-breaking discovery of seven temperate planets within the TRAPPIST-1 system has been hailed as a milestone in the development of exoplanetary science. Centred on an ultra-cool dwarf star, the planets all orbit within a sixth of the distance from Mercury to the Sun. This remarkably compact nature makes the system an ideal testbed for the modelling of rapid lithopanspermia, the idea that micro-organisms can be distributed throughout the Universe via fragments of rock ejected during a meteoric impact event. We perform N-body simulations to investigate the timescale and success-rate of lithopanspermia within TRAPPIST-1. In each simulation, test particles are ejected from one of the three planets thought to lie within the so-called ‘habitable zone’ of the star into a range of allowed orbits, constrained by the ejection velocity and coplanarity of the case in question. The irradiance received by the test particles is tracked throughout the simulation, allowing the overall radiant exposure to be calculated for each one at the close of its journey. A simultaneous in-depth review of space microbiological literature has enabled inferences to be made regarding the potential survivability of lithopanspermia in compact exoplanetary systems. 1Department of Physics, University of Warwick, Coventry, CV4 7AL 2Centre for Exoplanets and Habitability, University of Warwick, Coventry, CV4 7AL *Corresponding author: [email protected] Contents Universe, and can propagate from one location to another. This interpretation owes itself predominantly to the works of William 1 Introduction1 Thompson (Lord Kelvin) and Hermann von Helmholtz in the 1.1 Mechanisms for panspermia...............2 latter half of the 19th Century. -
Gold T. Rotating Neutron Stars As the Origin of the Pulsating Radio Sources
CC/NUMBER 8 ® FEBRUARY 22, 1993 This Week's Citation Classic Gold T. Rotating neutron stars as the origin of the pulsating radio sources. Nature 218:731-2, 1968; and Gold T. Rotating neutron stars and the nature of pulsars. Nature 221:25-7, 1969. [Center for Radiophysics and Space Research: and Cornell-Sydney University Astronomy Center. Cornell University, Ithaca. NY] Enigmatic, rapidly pulsating radio sources were preferred to attribute these sources to interpreted as rotating beacons sweeping over distant galaxies, not to stellar objects. the Earth, radiating out from rapidly rotating, The pulsars now seemed to repre- extremely collapsed stars ("neutron stars"). Nu- merous detailed predictions followed from this sent just the stellar objects I had dis- model, and all were soon verified. The model cussed then. Calculations existed for also accounted closely for the previously unex- the collapsed "neutron stars" that in- plained luminosity of the Crab Nebula. [The dicated approximately their size, as SCI® indicates that these papers have been small as a few kilometers, and their cited in more than 240 and 150 publications, mass, on the order of a solar mass.4 respectively.] Astronomers generally thought that even if they existed, they could never be discovered. However hot, a star so small could not be seen at astronomi- The Nature of Pulsars cal distances. But they had not con- sidered the energy concentration re- Thomas Gold sulting from the collapse: enormous Center for Radiophysics magnetic field strengths and a spin and Space Research energy quite comparable with the en- Cornell University tire content of nuclear energy of the Ithaca, NY 14853 star before its collapse. -
Cometary Panspermia a Radical Theory of Life’S Cosmic Origin and Evolution …And Over 450 Articles, ~ 60 in Nature
35 books: Cosmic origins of life 1976-2020 Physical Sciences︱ Chandra Wickramasinghe Cometary panspermia A radical theory of life’s cosmic origin and evolution …And over 450 articles, ~ 60 in Nature he combined efforts of generations supporting panspermia continues to Prof Wickramasinghe argues that the seeds of all life (bacteria and viruses) Panspermia has been around may have arrived on Earth from space, and may indeed still be raining down some 100 years since the term of experts in multiple fields, accumulate (Wickramasinghe et al., 2018, to affect life on Earth today, a concept known as cometary panspermia. ‘primordial soup’, referring to Tincluding evolutionary biology, 2019; Steele et al., 2018). the primitive ocean of organic paleontology and geology, have painted material not-yet-assembled a fairly good, if far-from-complete, picture COMETARY PANSPERMIA – cultural conceptions of life dating back galactic wanderers are normal features have argued that these could not into living organisms, was first of how the first life on Earth progressed A SOLUTION? to the ideas of Aristotle, and that this of the cosmos. Comets are known to have been lofted from the Earth to a coined. The question of how from simple organisms to what we can The word ‘panspermia’ comes from the may be the source of some of the have significant water content as well height of 400km by any known process. life’s molecular building blocks see today. However, there is a crucial ancient Greek roots ‘sperma’ meaning more hostile resistance the idea of as organics, and their cores, kept warm Bacteria have also been found high in spontaneously assembled gap in mainstream understanding - seed, and ‘pan’, meaning all. -
Fred Hoyle: Pioneer in Nuclear Astrophysics
PERSONALITY Fred Hoyle: pioneer in nuclear astrophysics Fred Hoyle, who died in 2001, is best known as a cosmologist. But, as Simon Mitton relates, his career in physics began with the weak interaction and moved on to a crucial discovery in nuclear physics. Fred Hoyle, the great cosmologist, nuclear astrophysicist and contro versialist, was born 90 years ago in the beautiful county of Yorkshire in the north of England. Hoyle's first science teacher was his father, who supplied the boy with books and apparatus for chemistry exper iments. By the age of 15 he was making highly toxic phosphine (PH3) Later in life Hoyle seldom worked at a desk in a faculty building, in his mother's kitchen, and terrifying his young sister with explosions. preferring a comfortable armchair at home. (St John's College.) In high school he excelled in mathematics, chemistry and physics, and in 1933 won a place at Cambridge to study physics. time Hoyle tracked him down he had just returned from spending six On arrival at Cambridge he immediately demonstrated his fierce months in Rome with Enrico Fermi. Peierls immediately set Hoyle independence by telling his astonished tutor that he was switching the task of improving Fermi's theory of beta decay, published in from physics to applied mathematics. The future nuclear astro 1934. This led, in 1937, to Hoyle's first research paper, "The gen physicist foresaw that Cambridge mathematics rather than lab eralised Fermi interaction". oratory physics would give him the right start as a theorist. The In 1938 Paul Dirac, who had won the Nobel prize in 1933, country boy displayed an astonishing talent at mathematics, even became Hoyle's supervisor because Peierls had left Cambridge for by the highest standards of the university. -
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BIO Web of Conferences 4, 00014 (2015) DOI: 10.1051/bioconf/20150400014 C Owned by the authors, published by EDP Sciences, 2015 From neonts to filionts and their progenies... Biodiversity draws its origins from the origins of life itself Marie-Christine Maurela Institut de Systématique, Évolution, Biodiversité (ISYEB - UMR 7205 – CNRS, MNHN, UPMC, EPHE), Muséum national d’Histoire naturelle, Sorbonne Universités, 45 rue Buffon, CP. 50, 75005 Paris, France “Should the question of the priority of the egg over the chicken, or of the chicken over the egg disturb you, it is because you assume that animals were originally what they are to-day; what madness!" The dream of d’Alembert, 1760, Denis Diderot Abstract. Since the origins, different modes of life exist. Indeed it is difficult to imagine how things could have been constructed by a single event that would have marked the birth of life. A brief historical background of the subject will be presented here. Then, we shall wander through the history of the discoveries that have led the way of experimental science over the last 150 years and shall dwell on one of the major paradigms, that of the RNA World. This paradigm illustrates the path followed by the living that tries all possible means when expressed at the molecular level as simple free molecule leading to RNA fragments and to modern subviral particles such as viroids then to ramifications and compartments. Between the ancient and the modern RNA world we underline how environment talks to molecules leading to the global living tissus which establish the ground of biodiversity. -
Exploring Biogenic Dispersion Inside Star Clusters with System Dynamics Modeling
Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted: 12 October 2020 doi:10.20944/preprints202010.0232.v1 Exploring Biogenic Dispersion Inside Star Clusters with System Dynamics Modeling Authors Javier D. Burgos. Corporación para la Investigacion e Innovación -CIINAS. Contact: [email protected] Diana C. Sierra. Corporación para la Investigacion e Innovación -CIINAS; Bogotá, Colombia. Contact: [email protected] Abstract The discovery of a growing number of exoplanets and even extrasolar systems supports the scientific consensus that it is possible to find other signs of life in the universe. The present work proposes for the first time, an explicit mechanism inspired by the dynamics of biological dispersion, widely used in ecology and epidemiology, to study the dispersion of biogenic units, interpreted as complex organic molecules, between rocky or water exoplanets (habitats) located inside star clusters. The 3 results of the dynamic simulation suggest that for clusters with populations lower than 4 M/ly it is not possible to obtain biogenic worlds after 5 Gyr. Above this population size, biogenic dispersion seems to follow a power law, the larger the density of worlds lesser will be the impact rate (훽.) value to obtain at least one viable biogenic Carrier habitat after 5 Gyr. Finally, when we investigate scenarios by varying β, a well-defined set of density intervals can be defined in accordance to its characteristic β value, suggesting that biogenic dispersion has a behavior of “minimal infective dose” of “minimal biogenic effective” events by interval i.e. once this dose has been achieved, doesn’t matter if additional biogenic impact events occur on the habitat. -
Advances in Understanding of Desiccation Tolerance of Lichens and Lichen-Forming Algae
plants Review Advances in Understanding of Desiccation Tolerance of Lichens and Lichen-Forming Algae Francisco Gasulla *, Eva M del Campo, Leonardo M. Casano and Alfredo Guéra * Department of Life Sciences, Universidad de Alcalá, Alcalá de Henares, 28802 Madrid, Spain; [email protected] (E.M.d.C.); [email protected] (L.M.C.) * Correspondence: [email protected] (F.G.); [email protected] (A.G.) Abstract: Lichens are symbiotic associations (holobionts) established between fungi (mycobionts) and certain groups of cyanobacteria or unicellular green algae (photobionts). This symbiotic association has been essential in the colonization of terrestrial dry habitats. Lichens possess key mechanisms involved in desiccation tolerance (DT) that are constitutively present such as high amounts of polyols, LEA proteins, HSPs, a powerful antioxidant system, thylakoidal oligogalactolipids, etc. This strategy allows them to be always ready to survive drastic changes in their water content. However, several studies indicate that at least some protective mechanisms require a minimal time to be induced, such as the induction of the antioxidant system, the activation of non-photochemical quenching including the de-epoxidation of violaxanthin to zeaxanthin, lipid membrane remodeling, changes in the proportions of polyols, ultrastructural changes, marked polysaccharide remodeling of the cell wall, etc. Although DT in lichens is achieved mainly through constitutive mechanisms, the induction of protection mechanisms might allow them to face desiccation stress in a better condition. The proportion and relevance of constitutive and inducible DT mechanisms seem to be related to the ecology at which lichens are adapted to. Citation: Gasulla, F.; del Campo, E.M; Casano, L.M.; Guéra, A. -
The Deep, Hot Biosphere (Geochemistry/Planetology) THOMAS GOLD Cornell University, Ithaca, NY 14853 Contributed by Thomas Gold, March 13, 1992
Proc. Natl. Acad. Sci. USA Vol. 89, pp. 6045-6049, July 1992 Microbiology The deep, hot biosphere (geochemistry/planetology) THOMAS GOLD Cornell University, Ithaca, NY 14853 Contributed by Thomas Gold, March 13, 1992 ABSTRACT There are strong indications that microbial gasification. As liquids, gases, and solids make new contacts, life is widespread at depth in the crust ofthe Earth, just as such chemical processes can take place that represent, in general, life has been identified in numerous ocean vents. This life is not an approach to a lower chemical energy condition. Some of dependent on solar energy and photosynthesis for its primary the energy so liberated will increase the heating of the energy supply, and it is essentially independent of the surface locality, and this in turn will liberate more fluids there and so circumstances. Its energy supply comes from chemical sources, accelerate the processes that release more heat. Hot regions due to fluids that migrate upward from deeper levels in the will become hotter, and chemical activity will be further Earth. In mass and volume it may be comparable with all stimulated there. This may contribute to, or account for, the surface life. Such microbial life may account for the presence active and hot regions in the Earth's crust that are so sharply of biological molecules in all carbonaceous materials in the defined. outer crust, and the inference that these materials must have Where such liquids or gases stream up to higher levels into derived from biological deposits accumulated at the surface is different chemical surroundings, they will continue to repre- therefore not necessarily valid. -
Fred Hoyle's Universe
GENERAL ARTICLE Fred Hoyle’s Universe Jayant V Narlikar This article recalls some of the seminal contri- butions to astronomy made by Fred Hoyle. His ideas were thought to be unrealistic at the time they were proposed, but have now been assim- ilated into mainstream science. A general com- ment that emerges from such examples is that highly creative individuals who are far ahead of their times do not get the recognition they de- Jayant V Narlikar is a serve once their ideas are rediscovered and ac- cosmologist and theoretical cepted as standard: for, by the time this hap- astrophysicist. He was a pens, they and their contributions are forgotten. research student and a long-time collaborator of 1. Introduction Fred Hoyle. He is the Founder Director of Fred Hoyle was arguably the most imaginative astro- IUCCA and is currently an emeritus professor there. physicist of the 20th century. He contributed very orig- He has made strong efforts inal ideas to astronomy and astrophysics in topics rang- to promote teaching and ing from the solar system to cosmology. He also made research in astronomy in contributions to fundamental physics, in particular to the universities. He has the concept of action at a distance. His studies on exo- written extensively in English and Marathi to biology evoked the most opposition from the Establish- popularize science. ment because their implications were so far reaching. This article presents glimpses of the work of this mul- tifaceted personality who is also known to the common man as an accomplished science populariser and writer of science ¯ction. -
First Life in Primordial-Planet Oceans: the Biological Big Bang Gibson/Wickramasinghe/Schild First Life in Primordial-Planet Oceans: the Biological Big Bang
Journal of Cosmology First life in primordial-planet oceans: the biological big bang Gibson/Wickramasinghe/Schild First life in primordial-planet oceans: the biological big bang Carl H. Gibson 1,2 1 University of California San Diego, La Jolla, CA 92093-0411, USA [email protected], http://sdcc3.ucsd.edu/~ir118 N. Chandra Wickramasinghe3,4 3Cardiff Centre for Astrobiology, 24 Llwynypia Road, Lisvane, Cardiff CF14 0SY [email protected] Rudolph E. Schild5,6 5 Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA 6 [email protected] Abstract: A scenario is presented for the formation of first life in the universe based on hydro- gravitational-dynamics (HGD) cosmology. From HGD, the dark matter of galaxies is H-He gas dominated planets (primordial-fog-particle PFPs) in million solar mass clumps (protoglobularstar- cluster PGCs), which formed at the plasma to gas transition temperature 3000 K. Stars result from mergers of these hot-gas-planets. Over-accretion causes stars to explode as supernovae that scatter life-chemicals (C, N, O, P, S, Ca, Fe etc.) to other planets in PGC clumps and beyond. These chemicals were first collected gravitationally by merging PFPs to form H-saturated, high-pressure, dense oceans of critical-temperature 647 K water over iron-nickel cores at ~ 2 Myr. Stardust fertil- izes the formation of first life in a cosmic hot-ocean soup kitchen comprised of all planets and their moons in meteoric communication, > 10100 kg in total. Ocean freezing at 273 K slows this biologi- cal big bang at ~ 8 Myr. HGD cosmology confirms that the evolving seeds of life are scattered on intergalactic scales by Hoyle-Wickramasinghe cometary panspermia. -
Science Loses Some Friends Francis Crick, Thomas Gold, and Philip Abelson
Monthly Planet October 2004 Science Loses Some Friends Francis Crick, Thomas Gold, and Philip Abelson By Iain Murray he scientifi c world lost three impor- Throughout his career, Abelson used which suggests that the universe and Ttant fi gures in recent weeks, as scientifi c principles to determine genu- the laws of physics have always existed Francis Crick, Thomas Gold, and Philip ine new developments from hype and in the same, steady state. This has since Abelson have all passed away. In their publicity stunts (he was famously dis- been supplanted as the dominant cos- careers, each demonstrated the best that missive of the scientifi c value of the race mological paradigm by the Big Bang science has to offer humanity. Their loss to the moon). In that, he should prove a theory. illustrates how much worse off the state role model for true scientists. After working at the Royal Greenwich of science is today than during their Observatory, Gold moved to the United glory years. Thomas Gold States to become Professor of Astron- Astronomer Thomas Gold had an omy at Harvard. From there he moved Philip Abelson equally distinguished career, in fi elds as to Cornell, where he demonstrated that Philip Abelson was a scientist of truly diverse as engineering, physiology, and the newly discovered “pulsar” phenom- broad talents. One of America’s fi rst cosmology; and he was never afraid of enon must contain a rotating neutron nuclear physicists, he discovered the being called a maverick. A fellow of both star (a star more massive than the sun element Neptunium and designed the the Royal Society and the National Acad- but just 10 km in diameter).