The Webb telescope has released its very first exoplanet image – here's what we can learn from it
NASA's James Webb Space telescope, which is performing much better than expectations, has just produced the first image of an exoplanet. The planet, HIP 65426b, is a gas giant rather like Jupiter, orbiting HIP 65426. It's presence had been inferred from data in 2017.
As a gas giant, it is not suitable for living organisms to have evolved but, with so many exoplanets being discovered, with over 5,000 discovered so far, and so many stars with potential planetary systems, it can't now be long before signs of life are detected on one or more of them.
When that happens, of course, it will destroy any remaining arguments from Creationists that the probability of a self-replicating molecule arising by chance is too small to be credible as an explanation for how life got going on Earth. It will show that, if the conditions are right, chemistry and physics alone are quite capable of producing that and the probability of a planet with those conditions being discovered, increases with every new exoplanet discovered.
The chances of finding such a planet are greater the closer the planetary system is to Earth for the simple reason that telescopes such as the James Webb, see distant objects as they were when the light left them, so a planet say, 10 billion lightyears away, will appear as it was 10 billion years ago. We know it took the Universe 10-11 billion years to give rise to Earth before life could get going some 500 million years later, so distant object may not have had time when we are seeing them, to have reached that stage. Closer objects will have had more time.
The image from the James Webb Space Telescope, and its significance is explained in an open access article in The Conversation by Professor Jonti Horner, Professor (Astrophysics), University of Southern Queensland, Australia. The article is reprinted here under a Creative Commons licence, reformatted for stylistic consistency. The original article can be read here.
Showing posts with label Abiogenesis. Show all posts
Showing posts with label Abiogenesis. Show all posts
Monday 5 September 2022
Tuesday 9 August 2022
God of the Gaps News - Creationism's Little Skrinking God Just Got a Lot Smaller
Olivine basalt
The basic problem with Creationism's favourite 'argument' - 'the God of the Gaps' - is not only that it is based on two fallacies - the argument from ignorant incredulity and the false dichotomy fallacies, but also that it tends to disappear every time the gap is subjected to scientific scrutiny.
That's exactly what has just happened with one of their favourite gaps - the origin of living organisms, which they always conflate with the theory of evolution of which it is not and never was a part. Evolution is what happened after ‘life’, or more precisely, self-replication, got started.
Essentially, living organisms can trace their origins back to a self-replicating molecule because once that had arisen, everything else follows naturally by Darwinian natural selection acting on small variations in the copies (the sieve of natural selection acting on each generation to filter out the best at producing copies of themselves and remove those least able to). Just such a molecule known to exist is a short length of RNA which has been shown to self-catalyse copies of itself in a mixture of nucleotides, by nothing more complex than the operation of the basic laws of chemistry.
But the question is, how did such a molecule first assemble?
Friday 13 May 2022
Abiogenesis News - Closing in to Fill Creationism's Favourite Gap - No God Found.
a, tRNA structure showing selected ribose and nucleobase modifications. The 3′-amino acid-acylated adenosine is located at the CCA 3′ end in contemporary tRNAs. 5-Methylaminomethyl uridine, mnm5U, is found in the wobble position 34. The amino acid-modified carbamoyl adenosine, (m6)aa6A (aa, amino acid), is present at position 37 in certain tRNAs. b, General RNA–peptide synthesis cycle based on mnm5U and m6aa6A. The structures of oligonucleotides are simplified and only terminal nucleobases are drawn.
It doesn't seem to have dawned on creationists who forlornly claim, despite the daily torrent of evidence to the contrary, that the Theory of Evolution is a theory in crisis. Far from the TOE being a 'theory in crisis', the reality is that it's the childish notion of creationism that's in crisis and which is being increasingly rejected even by religious people as a valid explanation for how life diverged. It's only by creative misrepresentation of the data, or by dismissing it out of hand, that creationist frauds are still able to pull the wool over the eyes of their credulous dupes, to maintain their cult’s superstitions.
One of their mainstays as an 'argument' which they invariably fall back on when confronted with unarguable evidence for evolution by natural selection and other mechanisms, is that none of the mechanisms explain the origin of 'life' itself (abiogenesis, life from non-life'), and without that, evolution would have nothing to work on. It is, of course, irrelevant to the mechanisms by which life diversified once replicators did get going, but, as usual with childish notions, the relevance of using the false dichotomy fallacy is lost on creationists who lack the critical thinking skills to spot the trick, and few if any of them could define the term 'life' in a scientifically meaningful way, anyway, so assume it means some magic ingredient that separates organic' molecules from inorganic ones. It is one of the last remaining gaps which they insist must contain their god and their belief is that, of all the gaps closed by science, this will be the one where a god is found. Their ever-shrinking little god has degenerated to the size of this one remaining gap. The magician that magicked 'life' from non-life and made them 'speshul'.
There are, of course, many possible alternative explanations for how a simple replicator could have got going and, indeed, there doesn't even need to be a single explanation since two or more replicators could have got together early on. If the result had given them an advantage over remaining separate, then this symbiosis would have been almost inevitable.
One of the more popular hypotheses amongst biologists is the 'RNA world hypothesis' that says, because RNA is still the functional unit of biological activity and it is simpler than DNA, it probably came first and DNA followed on as an evolved improvement, acting as RNA's data store and so became the functional organ of inheritance of genetic data.
This is the idea currently being expanded by a team at the Ludwig-Maximilians-Universität München, Germany. Their work has just been published, open access in Nature. They believe they have solved one of the outstanding problems with the theory - how RNA began catalysing the production of chains of amino acids to form peptides and short proteins without the peptides it codes for - a classic chicken and egg conundrum.
Like all chicken and egg conundrums, if this scenario is correct, it turns out that neither of them came first; they both emerged simultaneously and part of a developing complex out of simple pre-existing precursors.
As the Ludwig-Maximilians-Universität news release explains:
Thursday 14 April 2022
Abiogenesis News - Earliest Signs of Life Found in Canada
Layer-deflecting bright red concretion of haematitic chert (an iron-rich and silica-rich rock), which contains tubular and filamentous microfossils. This co-called jasper is in contact with a dark green volcanic rock in the top right and represent hydrothermal vent precipitates on the seafloor. Nuvvuagittuq Supracrustal Belt, Québec, Canada. Canadian quarter for scale.
Credit: D. Papineau.
Scientists from University College, London (UCL) and State Key Laboratory of Biogeology and Environmental Geology, School of Earth Sciences, China University of Geosciences, Wuhan, China, believe they may have found evidence of the earliest life on earth, from just 300 million years after its formation.
The traces of bacterial deposits were found in rocks from Quebec’s Nuvvuagittuq Supracrustal Belt which are believed to have been formed in hydrothermal vents - regarded as the most likely place for the formation of organised, self-replicating, biotic systems from inorganic sources.
The evidence is in the form of tubes, branching filaments and ellipsoids of haematite, very similar to structures formed today by chemosynthetic bacteria in hydrothermal vents such as those close to the Loihi undersea volcano near Hawaii, as well as other vent systems in the Arctic and Indian oceans. Although the scientists concede that these structures could conceivably be the result of chance chemical reactions, no structures like these that are the result of chemical reactions have ever been found.
The UCL press release which accompanied the team's open access publication in Science Advances explains the technique used to examine the microfossils:
Tuesday 18 January 2022
Abiogenesis News - Science Is Closing the Gap - Still no God(s) Found or Magic Needed
A team of researchers led by scientists from Rutgers University, New Jersey, USA, have brought us a little closer to understanding how the first self-replicating organisms arose on earth. And it didn't need magic supernatural deities to make it happen.
The Rutgers-led team have discovered the structures of proteins that may be responsible for the origins of life in the primordial soup of ancient Earth. They have published their findings, open access, in Science Advances
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Writing in Rutgers Today, John Cramer explains:
Friday 14 January 2022
New Spheres of Knowledge on the Origin of Life - University of Tsukuba
Researchers from the University of Tsukuba, Japan, in collaboration with East China Normal University, show that Escherichia coli cells become spherical when grown in conditions mimicking a primordial environment.
Image by Maximillian cabinet/Shutterstock
The point of this piece of research is not only what it tells us about the probable morphology of the earliest cells but what happened next.
It has long been assumed that the earliest cells would have been the simplest structures for maximal exchange of nutrients and waste with their environment and this would have been small spheres, since these give the maximal surface area to volume ratio. However, that remained an assumption until this experiment showed how a primordial environment would have favoured it.
The really interesting thing, however, is how the resultant organisms continued to diversify into, in this case, six distinct lines, with different sets of mutations all being selected to give the same advantages in that environment. This is perhaps best explained by the Tsukuba University press release:
Wednesday 3 March 2021
Abiogenesis News - That God-Shaped Gap is Getting Smaller!
A replicator made of tRNA-like sequences
© Kudella / LMU
Another shovel-full of science just got thrown into Creationism's favourite God-shaped gap, abiogenesis.
A Team of German scientists led by Professor Dieter Braun of the Ludwig Maximilians Universität (LMU), München, have shown how to resolve the classic 'chicken and egg' conundrum when explaining the origins of living systems, that proteins are required for transcription of the genetic information, but their synthesis itself depends on transcription.
It involved Darwinian evolution at a molecular level! As always when science solves a problem, magic was found not to be required!
The LMU press release explains the problem:
Thursday 25 February 2021
Abiogenesis News - Creationism's Favourite God-Shaped Gap Just Got Smaller Again
“Protocells” containing bubble-like compartments formed spontaneously on a mineral-like and encapsulated fluorescent dye. This could have been what happened 3.8 billion years ago when cells first began to form.
Image: Karolina Spustova.
No wonder Creationists often come across as paranoid. At times it must feel as though their favourite dogmas and god-shaped gaps are under siege by science and constantly in danger of being overthrown or closed altogether, like so many former gaps in which they sat their favourite god(s); all found to be empty when science shone a light in them.
One of their favourites, and often their only fall-back position, is that abiogenesis hasn't been explained by science, and that easily becomes a claim that it can't be explained without resort to magic by a magic man because living things contain special god-magic called 'life' that can't be identified or even explained.
Then along comes another paper, like this one from scientists at the University of Oslo, published by the Biophysics Society, that chips away a little more at this dogma, by showing not only how simple cells got started but by showing how 'life' is simply chemical and physical processes, all understandable as properties of matter, with no magic involved.
This paper is yet another in a long line of papers all reducing the size of creationism's god-shaped abiogenesis gap, and deals with how proto-cells became internally organised, in this case, with the formation of 'bubbles' or vacuoles that are a fundamental part of living cells today.
The Biophysical Society press release explains:
Saturday 20 February 2021
Evolution News - Evolution Before Abiogenesis
Fig. 1.
Templated ligation of random sequence DNA 12-mers. (A) Before cells evolved, the first ribozymes were thought to perform basic cell functions. In the exponentially vast sequence space, spontaneous emergence of a functional ribozyme is highly unlikely, therefore preselection mechanisms were likely necessary. (B) In our experiment, DNA strands hybridize at low temperatures to form three-dimensional complexes that can be ligated and preserved in the high temperature dissociation steps. The system self-selects for sequences with specific ligation site motifs as well as for strands that continue acting as templates. Hairpin sequences are therefore suppressed. (C) Concentration analysis shows progressively longer strands emerging after multiple temperature cycles. The inset (A-red, T-blue) shows that, although 12-mers (88,009 strands) have essentially random sequences (white), various sequence patterns emerge in longer strands (60-mers, 235,913 strands analyzed). (D) Samples subjected to different number (0 to 1,000) of temperature cycles between 75 °C and 33 °C. Concentration quantification is done on PAGE with SYBR poststained DNA.
© 2021 The authors
News today that research physicists at Ludwig-Maximilians-Universität, München, Germany (LMU) may have solved one of the key questions relating to abiogenesis - how did order begin to emerge from the chaos of random organic chemicals? It appears that this was the result of Darwinian evolution of molecules!
In the words of the LMU New release:
Before life emerged on Earth, many physicochemical processes on our planet were highly chaotic. A plethora of small compounds, and polymers of varying lengths, made up of subunits (such as the bases found in DNA and RNA), were present in every conceivable combination. Before life-like chemical processes could emerge, the level of chaos in these systems had to be reduced. In a new study, LMU physicists led by Dieter Braun show that basic features of simple polymers, together with certain aspects of the prebiotic environment, can give rise to selection processes that reduce disorder.In common with many researchers in this field, the LMU team placed abiogenesis in "narrow, water-filled chambers within porous volcanic rocks on the sea bottom", in other words in the porous rocks around deep ocean hydrothermal vents.
These studies showed that, in the presence of temperature differences and a convective phenomenon known as the Soret effect, RNA strands could locally be accumulated by several orders of magnitude in a length-dependent manner. “The problem is that the base sequences of the longer molecules that one obtains are totally chaotic“, says Braun. Evolved ribozymes (RNA-based enzymes) have a very specific base sequence that enable the molecules to fold into particular shapes, while the vast majority of oligomers formed on the Early Earth most probably had random sequences. “The total number of possible base sequences, known as the ‘sequence space’, is incredibly large,” says Patrick Kudella, first author of the new report. “This makes it practically impossible to assemble the complex structures characteristic of functional ribozymes or comparable molecules by a purely random process.” This led the LMU team to suspect that the extension of molecules to form larger ‘oligomers’ was subject to some sort of preselection mechanism.
Monday 16 November 2020
Evolution News - Closing Creationism's Abiogenesis God-Shaped Gap
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| Early Earth (Artist's impression) Credit: NASA's Goddard Space Flight Center Conceptual Image Lab |
Abiogenesis is the creation industry's favourite fall-back gap for when they find the evidence for evolution irrefutable and overwhelming. Science is then challenged to reproduce a fully functional complex cell in a laboratory, starting out with a few raw chemicals.
What they've been conditioned to believe is that any current gap in our scientific knowledge will, unlike all the previous gaps, never be closed, so it must be done by a god, notwithstanding the absurd false dichotomy in that argument.
So, these instances of their abiogenesis god-shaped gap shrinking considerably under scientific scrutiny is bound to produce hand-waving denialism in even the hardiest of creationists. It is, of course just another small step by science toward a comprehensive understanding of how self-replicating, entropy-managing, free-living collections of chemicals in a bag, started evolving into today's amazing biodiversity.
Thursday 29 October 2020
Evolution News - Closing Creationism's God-Shaped Gap
Models for potential precursors of cells endure simulated early-Earth conditions | Eberly College of ScienceAnother shovel-full of science has just been thrown into Creationism's favourite God-shaped gap - abiogenesis - by a bunch of scientists from Penn State University Eberley College of Science.
The abiogenesis question is the increasingly-used last resort of Creationists who can no longer mount a serious challenge to the science of evolution. Never slow to use a dishonest false dichotomy fallacy, they challenge scientists to explain how the first 'life' assembled without the intervention of a magic creator, and to replicate it in a laboratory - as though the ultimate proof of a scientific theory is to replicate it in a laboratory, regardless of the fact that the theory might involve a whole planet or conditions only found near hydrothermal vents in the ocean abyss, and millions of years!
But that God-shaped gap just got smaller, as it has been doing now for several decades, as chemists, physicists and geologists discover more about the conditions on the early Earth when living systems first arose, and about the chemical and physical processes that were possible, even likely under those conditions.
Sunday 4 October 2020
Creationism's Abiogenesis God-Shaped Gap Just Got Smaller
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| From the mixture of all four nucleobases, A:T pairs emerged at about 100 degrees Celsius and G:C pairs formed at 200 degrees Celsius. Credit: Ruđer Bošković Institute, Ivan Halasz |
It's been one of those awful weeks for Creationists again.
Not only did we have those lovely wasps embedded in 25-million-year-old amber, and then their beloved Covidiot In Chief, Donald Trump being laid low with the virus he had pronounced to be a hoax and a mild illness that would all be over by April, but now we have another shovel-full thrown into their favourite god-shaped hole, abiogenesis. Abiogenesis is the current fall-back of every creationist who runs out of arguments against evolution, and to which they cling like a fool to a deck-chair in the face of an on-rushing tsunami.
This time we have news that a team led by Ivan Halasz from the Ruđer Bošković Institute and Ernest Meštrović from the pharmaceutical company Xellia have shown just how easy it must have been to create DNA by perfectly natural processes in conditions which would have been found on the early Earth. Their findings were published a few days ago in the journal Chemical Communications, regrettably behind a paywall. However, the news release from the Deutsches Elektronen-Synchrotron (DESY), A Research Centre of the Helmholtz Association, explains the problem and the team's findings:
Monday 14 September 2020
Terrible News for Creationists - Signs of Life on Another Planet
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| Venus in real colors, processed from Mariner 10 images.
Image credit: Mattias Malmer / NASA. |
Creationists have been putting all their eggs in one basket and telling their credulous dupes that the possibility of living organisms arising by natural processes on Earth are so low as to be impossible - so they should conclude that it must have been created by the Christian god exactly as the Bible says.
Now it seems their egg basket may have been kicked over by science. Leaving aside the false dichotomy fallacy in their non sequitur of an argument, the discovery that there may be life in the atmosphere of Venus blows their big scary number tactic out of the water. If it could have happened on Venus it could happen on Earth.
And they still face the prospect of signs of life, either now or in the past, in the soil of Mars and maybe in the waters on some of the moons of Jupiter and Saturn!
Sunday 9 August 2020
How Self-Replicating RNA Got Made - Naturally
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| A hydrothermal vent on the Niua underwater volcano in the Lau Basin, southwest Pacific Ocean. The sort of place abiogenesis could have happened. |
I hate to say, "I told you so!", but... I told you so!
Readers of my books and blog-posts may remember how I elaborated on the ten-step process, proposed by Nick Lane and Michael Le Page in New Scientist in 2009, to explain how abiogenesis could have come about, in my blog-post Perfectly Plausible Abiogenesis, and in my popular book What Makes You So Special? From the Big Bang to You, in which I wrote:
Tuesday 23 June 2020
Bad News for Creationists - Filling the Abiogenesis Gap
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| The characteristic (HhH)2 fold and its binding to the minor groove of a modern DNA molecule. How did the first ones form? |
It's another day when scientists incidentally and without conscious effort, refute creationism with science.
One of creationism favourite god-filled gaps is the question of abiogenesis with constant questions about where the first proteins came from and how they self-assembled from non-living raw materials. This paper answers them. It details the findings of a team of scientists led by Prof. Dan Tawfik of the Weizmann Institute of Science and Prof. Norman Metanis of the Hebrew University of Jerusalem and including scientists from Department of Chemistry, University of Washington, Seattle, WA, USA.
Sadly, once again a scientific paper of wide general interest is behind a firewall, however we have a news article from the Weizmann Institute of Science to explain the research:
Thursday 21 May 2020
Creationism News - Another Gap Closing!
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| Amino Acid Chirality chirality with hands from http://www.nai.arc.nasa.gov/ A "chiral" molecule is one that is not superposable with its mirror image. Like left and right hands that have a thumb, fingers in the same order, but are mirror images and not the same, chiral molecules have the same things attached in the same order, but are mirror images and not the same. Although most amino acids can exist in both left and right handed forms, Life on Earth is made of left handed amino acids, almost exclusively. Source: Wikipedia |
One of the creationist 'gap' arguments you see pulled out of the toy box and dusted off once in a while is the so-called 'chirality' or handedness problem. The reason it's used so infrequently is probably because so few creationists have the capacity to understand what the term 'chirality' means. The 'problem' is to explain why all amino acids (and so biological proteins) and sugars are composed only of one enantiomere, 'L' in the case of amino acids and 'D' in the case of sugars.
Like so many creationist presuppositional 'gap' arguments, the answer is that the presupposed god did it. No evidence need ever be offered of the existence of this god nor any explanation of how or why it did whatever it is claimed to have done. 'Magic' and 'mystery' satisfy a creationist.
But now this creationist-satisfying gap might have closed according to a paper published in The Astrophysics Journal Letters by two STanford University physicists, Noemie Globus and Roger D. Blandford.
Taylor Kubota of Stanford News Service explains:
Wednesday 1 May 2019
Perfectly Plausible Abiogenesis
I get more than a little bit bored with almost every debate with creationists eventually, and often very quickly, coming down to a demand that we explain abiogenesis, or more likely an assertion that it can't be explained because it's 'impossible'. Then comes the parrot squawk, "you can't get life from non-life", as though any of them could define this 'life' thing.
So, with that in mind, I thought I would both give a puff for my book, What Makes You So Special? From the Big Bang to You and put on record a perfectly plausible explanation for how abiogenesis could have happened. Note, it's not meant to be an account of how it actually happened, just how it could have happened, to refute creationist claims that it is impossible.
If any creationists wishes to substantiate that claim, please feel free to go through the following ten steps and say which laws of chemistry and/or physics would make one or more of them impossible. If you can't, clearly, it is not impossible.
Friday 31 August 2018
Building Life's Building Blocks
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| Researchers have designed a synthetic small protein that wraps around a metal core composed of iron and sulfur. This protein can be repeatedly charged and discharged, allowing it to shuttle electrons within a cell. Such peptides may have existed at the dawn of life, moving electrons in early metabolic cycles. Image: Vikas Nanda Source: Rutgers Today |
Researchers at Rutgers University have found perhaps the only hard evidence that simple protein catalysts may have existed when life began.
It has long been postulated that life may have begun on iron and sulphur-containing rocks in sea water and that these metals, bound to short peptide chains could have acted as catalysts for simple metabolic processes, long before RNA, DNA and bigger, more complex proteins evolved.
The team used computer modelling to design a short, 12-amino acid peptide for testing. This one had just two different amino acid from the 20 of which larger proteins are made. Being short and simple, it could easily have arisen spontaneously and the metal cluster at the heart of the catalyst are similar to those found in in the oceans on early Earth when life arose.
Wednesday 8 November 2017
'Missing Link' in Abiogenesis Found!
Scientists find potential 'missing link' in chemistry that led to life on EarthYou know, sometimes I get carried away and fantasise about creationist frauds like Ham, Comfort and Hovind hearing the tune Aproaching Menace by Neil Richardson as they read yet another scientific paper showing how science is closing in on one of their sacred dogmas - that only God can create life.
But then I come back to reality and remember that they don't do science and evidence, so none of this makes any difference to them. They'll still claim it's impossible, knowing they can rely on their willing dupes not to check just in case.
Only three days ago I reported here on the work of a team from the Georgia Institute of Technology, Atlanta, GA, USA who are homing in on one of the pre-biotic precursors of one of the fundamental cell processes. Just a day later we had this paper published in Nature Chemistry showing how another fundamental process could similarly have arisen pre-biotically. The process is that of phosphorylation, i.e, adding a phosphate group to three key components of cells.
Sunday 5 November 2017
The Chemical Origin of Life
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| Accretion of SSU rRNA as illustrated by helices 7–10/es3 from species of increasing complexity. A four-way junction at the surface of the common core, formed by helices 7–10, has expanded by accretion. Accretion adds to the previous rRNA core, leaving insertion fingerprints. (A and B) Secondary (A) and 3D (B) structures are preserved upon the addition of new rRNA. (C) Superimposition of the 3D structures highlights how new rRNA accretes with preservation of ancestral rRNA. (D) A characteristic insertion fingerprint is shown in red and blue boxes. In all panels, the rRNA that approximates the common core is blue. An expansion observed in both archaea and eukaryotes is green. An expansion that is observed only in eukaryotes is gold. An additional expansion in higher eukaryotes (mammals) is red.* |
A team of scientist from Georgia Institute of Technology, Atlanta, GA, USA believe they are close to solving one of the mysteries of how living systems first arose from chemical precursors. They believe they have identified a small section of the ribosome which is so fundamental that it is common to all living organisms, from the simplest single-celled organisms to the most complex multicellular plants and animals
In short, this looks to be the starting point for life and a structure that was present in LUCA and maybe before it.
Rather than the bottom up approach where scientists have attempted, with limited success so far, to reconstruct the fundamental units from which living systems could have arisen, the team took a top down approach by reverse engineering the cell organelle common to all living cells and therefore almost certainly present from the first moments, maybe even before something that could be called 'living' existed, the ribosome.
Ribosomes are composed of a tangle of RNA and proteins and are fundamental to living cells in that they only perform one task - they translate the code in DNA and construct proteins from amino acids. They differ from one species to another only in the 'ornamentation' present on their surface, and this gave the clue to the method of reverse engineering the team used.
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