On Friday, March 6, 2020 at 7:39:33 PM UTC-6, Brent wrote: > > > > On 3/6/2020 3:31 PM, Lawrence Crowell wrote: > > On Friday, March 6, 2020 at 5:28:31 PM UTC-6, Lawrence Crowell wrote: >> >> On Friday, March 6, 2020 at 9:03:21 AM UTC-6, John Clark wrote: >>> >>> Galactic clusters are the largest structures in the universe held >>> together by gravity and the Ophiuchus Supercluster contains 4021 known >>> galaxies, it's likely none of them contain life, much less intelligent >>> life. Telescopes have seen evidence that the largest galaxy in the center >>> of the cluster underwent a gargantuan explosion at least 240 million years >>> earlier, it's 390 million light years away so the explosion happened at >>> least 630 million years ago. It's thought that 270 million solar masses of >>> gas and dust was sucked into the black hole at the center of the galaxy >>> producing something equivalent to a supernova going off every month for a >>> 100 million years. Something like that would probably sterilize not only >>> the galaxy but the entire cluster. And Ophiuchus is relatively nearby so >>> it's almost certain there are more distant clusters that suffered even >>> larger explosions. It looks like the Milky Way has just been lucky. >>> >>> DISCOVERY OF A GIANT RADIO FOSSIL IN THE OPHIUCHUS GALAXY CLUSTER >>> <https://www.icrar.org/wp-content/uploads/2020/02/2002.01291.pdf> >>> >>> John K Clark >>> >> >> Even if life is terribly improbable, such as how nucleotides emerged or >> even worse ribosomes, it did so in this galaxy. It is possible that biology >> has been spread around this galaxy with asteroid impacts. Ejecta from such >> impacts on a bio-active planet could send microbes on a long journey to >> another planet. It is then plausible that biology is fairly common in this >> galaxy, but not others. >> >> LC >> > > > > https://www.u-tokyo.ac.jp/focus/en/press/z0508_00094.html > > Is life a game of chance? Study reveals life in the universe could be > common, but not in our neighborhood Research news > > To help answer one of the great existential questions - how did life > begin? - a new study combines biological and cosmological models. Professor > Tomonori Totani from the Department of Astronomy looked at how life’s > building blocks could spontaneously form in the universe - a process known > as abiogenesis. > > If there’s one thing in the universe that is certain, it’s that life > exists. It must have begun at some point in time, somewhere. But despite > all we know from biology and physics, the exact details about how and when > life began, and also whether it began elsewhere, are largely speculative. > This enticing omission from our collective knowledge has set many curious > scientists on a journey to uncover some new detail which might shed light > on existence itself. > > RNA shares chemical components with DNA and is an essential precursor to > the existence of life. > > As the only life we know of is based on Earth, studies on life’s origins > are limited to the specific conditions we find here. Therefore, most > research in this area looks at the most basic components common to all > known living things: ribonucleic acid, or RNA. This is a far simpler and > more essential molecule than the more famous deoxyribonucleic acid, or DNA, > that defines how we are put together. But RNA is still orders of magnitude > more complex than the kinds of chemicals one tends to find floating around > in space or stuck to the face of a lifeless planet. > > RNA is a polymer, meaning it is made of chemical chains, in this case > known as nucleotides. Researchers in this field have reason to believe that > RNA no less than 40 to 100 nucleotides long is necessary for the > self-replicating behavior required for life to exist. Given sufficient > time, nucleotides can spontaneously connect to form RNA given the right > chemical conditions. But current estimates suggest that magic number of 40 > to 100 nucleotides should not have been possible in the volume of space we > consider the observable universe. > > > Such estimates generally just assume pure random trials. And they > overlook the build up and availability of short chains if they're in a > confined volume. Here's an actual experiment showing you don't need 40 > nucleotides to get replication: > > *Letters to Nature* > *Nature 382, 525 - 528 (08 August 1996); doi:10.1038/382525a0* > *David H. Lee, Juan R. Granja, Jose A. Martinez, Kay Severin & M. Reza > Ghadiri* > *Departments of Chemistry and Molecular Biology and the Skaggs Institute > for Chemical Biology, The Scripps Research Institute, La Jolla, California > 92037, USA* > *THE production of amino acids and their condensation to polypeptides > under plausibly prebiotic conditions have long been known1,2. But despite > the central importance of molecular self-replication in the origin of life, > the feasibility of peptide self-replication has not been established > experimentally3–6. Here we report an example of a self-replicating peptide. > We show that a 32-residue α-helical peptide based on the leucine-zipper > domain of the yeast transcription factor GCN4 can act autocatalytically in > templating its own synthesis by accelerating the thioester-promoted > amide-bond condensation of 15- and 17-residue fragments in neutral, dilute > aqueous solutions. The self-replication process displays pa**rabolic > growth pattern with the initial rates of product formation correlating with > the square-root of initial template concentration. * > > When Ventura County Freethinkers were challenged to debate evolution with > a team from a local creationist Church I estimated the time to produce a > self-replicating RNA based on complete mixing in an ocean containing 1g of > organic molecules per metric ton and a complete mixing time of 10 million > years for the ocean. I got 300 million years. > > There are also abiogenesis theories based on the concentration of organic > molecules near alkaline ocean vents (white smokers) where lipid membranes > could contain and concentrate biomolecules and provide energy from ion > gradients. There's a good lecture on this by Nick Lane to the Royal > Academy online. The fact that bacterial or archean life appeared on Earth > almost as soon as it was cool enough for survival suggests that estimates > yielding low probability are way off. > > Brent > > Certainly the question is open. Religious people will always try to squeeze their god into gaps in our understanding. The occurrence of life on Earth in such a rapid time does pose a possibility for a fairly rapid occurrence, at least on a geological time scale. for life. On the other hand if life emerged elsewhere and fell to the early Earth on a meteoroid that also could cause an rapid emergence of life. Really in effect we are faced with the point where Darwinian evolution sort of craps out on us and how life emerged is a new question that if answered will be an entirely new science.
LC > > A diagram to show the inflationary history of the universe. Image by NASA > CC-0 > > “However, there is more to the universe than the observable,” said Totani. > “In contemporary cosmology, it is agreed the universe underwent a period of > rapid inflation producing a vast region of expansion beyond the horizon of > what we can directly observe. Factoring this greater volume into models of > abiogenesis hugely increases the chances of life occuring.” > > Indeed, the observable universe contains about 10 sextillion (1022) > stars. Statistically speaking, the matter in such a volume should only be > able to produce RNA of about 20 nucleotides. But it’s calculated that, > thanks to rapid inflation, the universe may contain more than 1 googol (10 > 100) stars, and if this is the case then more complex, life-sustaining > RNA structures are more than just probable, they’re practically inevitable. > > “Like many in this field of research, I am driven by curiosity and by big > questions,” said Totani. “Combining my recent investigation into RNA > chemistry with my long history of cosmology leads me to realize there is a > plausible way the universe must have gone from an abiotic (lifeless) state > to a biotic one. It’s an exciting thought and I hope research can build on > this to uncover the origins of life.” > ---------------- > > > paper is open access: > > https://www.nature.com/articles/s41598-020-58060-0 > -- > You received this message because you are subscribed to the Google Groups > "Everything List" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected] <javascript:>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/everything-list/25923455-0d2d-456d-bfb0-0ef36e1f1573%40googlegroups.com > > <https://groups.google.com/d/msgid/everything-list/25923455-0d2d-456d-bfb0-0ef36e1f1573%40googlegroups.com?utm_medium=email&utm_source=footer> > . > > > -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/54826433-3f40-415a-ae92-4b5640a87c0d%40googlegroups.com.
