What'sNEW Apr - Jun 2021
Scientists estimate that there are about 10^31 individual viral particles inhabiting the oceans alone at any given time — 10 billion times the estimated number of stars in the known Universe.
 "Beyond coronavirus: the virus discoveries transforming biology" by Amber Dance, doi:10.1038/d41586-021-01749-7, Nature, 30 Jun 2021.
 Viruses and Other Gene Transfer Mechanisms has discussion.
 Earth-like biospheres on other planets may be rare, Newswise, 24 Jun 2021, and
Are Planets with Continuous Surface Habitability Rare? by Alex Tolley, Centauri Dreams, 28 May 2021; re:
"Efficiency of the oxygenic photosynthesis on Earth-like planets in the habitable zone" by Giovanni Covone et al., doi:10.1093/mnras/stab1357, Monthly Not. RAS, 19 May 2021.
Gaia explains how life could steer and stabilize a planet's environment.
"Water activity in Venus’s uninhabitable clouds and other planetary atmospheres" by Hallsworth, J.E., Koop, T., Dallas, T.D. et al., Nature Astronomy, 28 Jun 2021.
Life could exist in the clouds of Jupiter but not Venus, Queen’s University Belfast +Newswise, 28 Jun 2021.
14 Sep 2020: Venus backstory.
Life on ...Other Planets? has links.
| 29 Jun 2021 |
What'sNEW about HGT  |
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One other viewpoint that Darwin could not have appreciated was the role of horizontal gene transfer in shaping genetic novelty. This meant that rather than invent their own solutions in the face of selective challenges, organisms could simply steal these solutions from others.
— Harmit Malik, evolutionary geneticist, Fred Hutchinson Cancer Research Center
...Asking experts how Darwin's theories hold up..., interviews by Rita Ponce, Massive Science, 27 Jul 2021.
China's Zhurong Rover on Mars Astronomy Picture of the Day, 15 Jun 2021.
Tianwen-1, the Chinese Mars mission, Wikipedia.
More eukaryotic organisms can survive very long dormancy.
"A living bdelloid rotifer from 24,000-year-old Arctic permafrost" by Lyubov Shmakova et al., Cur. Biol., 07 Jun 2021.
'Zombie' organism comes back to life after 24,000 years, Yahoo News, 18 Jun 2021.
An arc of galaxies 3 billion light-years long may challenge cosmology by Lisa Grossman, Science News, 10 Jun 2021.
"We discuss the implications for the Giant Arc... for the fundamental assumption of homogeneity in cosmology" by A. M. Lopez et al., [abstract only], American Astronomical Society annual meeting, 07 Jun 2021.
 Thanks, John Hughes, Whitefish MT.
The End... cites alternatives to the standard big bang, with updates.
| 11 Jun 2021 |
What'sNEW about HGT |
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Horizontal gene transfer (HGT) is the most straightforward way for a species to acquire wholly new genetic programming. Mainstream science has noticed that it looks like the only way for prokaryotes. The same paradigm shift for eukaryotes is now apparently under way. A review article cites evidence and experts worldwide:
The rate of actual horizontal transfer is probably much, much higher than we realize.
The detected transfer events must ...be only a tiny proportion of the full number of transfers that occur.
The unsettling possibility is that horizontal DNA transfers could happen all the time.
Whatever the rate of horizontal transfers, their cumulative impact on evolutionary history is undeniable.
"DNA Jumps Between Animal Species. No One Knows How Often." by Christie Wilcox, Quanta Magazine, 18 May 2021.
Viruses and Other Gene Transfer Mechanisms has many examples.
"Radioactivity May Fuel Life Deep Underground and Inside Other Worlds", by Jordana Cepelewicz, Quanta Magazine, 18 May 2021.
"Inside Deep Undersea Rocks, Life Thrives Without the Sun", by Jordana Cepelewicz, Quanta Magazine, 13 May 2021.
Bacteria... has lots more about their versatility.
Tardigrades can survive instantaneous pressure up to about 10,000 atmospheres, which an impact at .8 km/s can create. This news follows tests by a pair of UK astrobiologists using a gas gun. Tardigrades also tolerate even higher static pressure, hard vacuum, complete dessication, ionising radiation, temperature extremes and weightlessness, at various life stages, apparently without time limit. Surely they could manage to arrive safely on lots of planets.
"Tardigrade Survival Limits in High-Speed Impacts – Implications for Panspermia and Collection of Samples from Plumes Emitted by Ice Worlds", by Alejandra Traspas and Mark J. Burchell, doi:10.1089/ast.2020.2405, Astrobiology, 11 May 2021.
Tardigrades survive impacts of up to 825 meters per second by Bob Yirka, Phys.org, 21 May 2021.
Thanks, Peter S. Thompson. And Google Alerts:
Are Water Bears Extraterrestrial? by Emma Sours et al., The Ohio State University, 21 Feb 2021.
More about tardigrades.
What Makes Tiny Tardigrades Nearly Radiation Proof by Carl Zimmer, The New York Times, 12 Apr 2024.
"the theory that microbes in space transmit life to habitable bodies" is the definition of panspermia that I have always accepted. Am I negligent to ignore the possible role of larger specimens? In addition to tardigrades, many plant seeds can tolerate extremes. French botanist David Tepfer has long advocated panspermia by plant seeds.
"The origin of life, panspermia and a proposal to seed the Universe", by David Tepfer, Plant Science, Dec 2008.
David Deamer is a very respected origin-of-life researcher whom I admire. Now he has written a brief wide-angled introduction to his field. In everyday language, he starts with the formation of habitable planets. Then, for life to emerge on them, he especially likes cyclical environments. But he leaves out nothing – he even mentions panspermia. The final third of the book is titled, "What we still need to discover."
Yes, he admits, lots is unknown. But from our unorthodox perspective, some of his most casual assertions were jarring. Brave origin-of-life researchers are sustained by the knowledge that life did have a beginning. It's only a conviction, isn't it? Later, Deamer says the organic compounds in Murchison must have been synthesized by non-biological chemical reactions. Wait, when did biology get ruled out for that?
As usual, the software aspect of the origin-of-life problem is effectively ignored. I think it's a fatal problem by itself. Obviously, I do not share Deamer's faith. Nonetheless, he is a very respected origin-of-life researcher whom I admire. For a brief wide-angled introduction to the field, with lots of orthodox knowledge that's easy to read, this book is perfect.
Origin of Life:
What Everyone Needs to Know, by David W. Deamer, Oxford University Press, 2019.
Sabbaticals, Self-Assembly, and Astrobiology, David W. Deamer's personal story, Astrobiology, Aug 2011.
The RNA World and Other Origin-of-Life Theories has history and updates.
Deamer says panspermia lacks testable predictions, but panspermia makes firm predictions: life on Mars – and anywhere else – will be related to life here. If there's water, there's life. Meteorites will contain evidence of life. In cosmic ancestry, HGT must first deliver the innovative genetic programs. Viruses will transfer genes. Plenty of testable predictions.
Life on Mars! contains a table with panspermia's [1996] predictions for life there.
The Evolution Prize,
New genetic programs and
09 May 2002: more tests or predictions.
Can The Theory Be Tested? includes a Postscript with relevant discussion.
| 14 May 2021 |
What'sNEW about HGT |
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...DNA copies of viral subgenomic RNAs may integrate into the DNA of the host cell by a reverse transcription mechanism. Stem cell biologist Rudolf Jaenisch and gene regulation specialist Richard Young of the Massachusetts Institute of Technology first published this suggestion about COVID-19 in December. Naturally, alarm ensued. Now the finding seems confirmed.
We believe viruses are the primary driver of evolutionary innovation. Their infectivity allows whole populations to be transformed at once, as Susumu Ohno wrote 50 years ago. The MIT researchers know this.
Indeed, nonretroviral RNA virus sequences have been detected in the genomes of many vertebrate species, with several integrations exhibiting signals consistent with the integration of DNA copies of viral mRNAs into the germline via ancient long interspersed nuclear element (LINE) retrotransposons.
Today genomicists recognize endogenous retroviruses making up 8% of the human genome. Whether any of the genome of the new coronavirus (illustrated in blue) gets endogenized – becomes part of the human genome – remains to be seen.
"Reverse-transcribed SARS-CoV-2 RNA can integrate into the genome of cultured human cells..." by Liguo Zhang et al., doi:10.1073/pnas.2105968118, PNAS, 25 May 2021.
"Do coronavirus genes slip into human chromosomes?" by Jon Cohen, Science, 14 May 2021.
Viruses and Other Gene Transfer Mechanisms has background and updates.
"An ancient viral epidemic involving host coronavirus interacting genes more than 20,000 years ago in East Asia" by Yassine Souilmi et al., doi:10.1016/j.cub.2021.05.067, Current Biology, 24 Jun 2021.
| 11 May 2021 |
What'sNEW about HGT |
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A unique example of direct vertebrate to vertebrate DNA transmission from herring to smelt has occurred, say two Canadian molecular biologists. They suggest that the transferred DNA may have been attached to sperm during spawning. Accompanying transposable elements provide a clue to the direction of the transfer.
"Horizontal Gene Transfer in Vertebrates..." by Laurie A. Graham and Peter L. Davies doi:10.1016/j.tig.2021.02.006, Trends in Genetics, 01 Jun 2021.
Viruses... lists many examples of HGT in all domains, but few or none directly between vertebrates.
Is there life on Mars? The evidence has produced no consensus, but adamance abounds. A new article using NASA images to draw bold conclusions prompts equally bold outrage. This science looks as polarized as politics.
Fungi on Mars?... by Rhawn Joseph et al., ResearchGate, May 2021.
...claims for life on Mars are shoddy and unscientific by Jackson Ryan, ccnet, 06 May 2021.
Thanks, Lee Edwards and Stan Franklin.
FWIW, I think Joseph et al. are onto something with the blueberries. But the "white amorphous mass" (Fig. 17) could simply be a spot of sunlight.
17 May 2020: also from Joseph et al.
Life on Mars! has background.
... if we know the amount of iron present in a planet's mantle, we can predict how thick its crust will be and, in turn, whether liquid water and an atmosphere may be present.
"The effect of core formation on surface composition and planetary habitability" by Brendan Dyck, Jon Wade and Richard Palin, arXiv:2104.10612, 21 Apr 2021.
...researcher uses geology to help astronomers find habitable planets by Nathan Skolski, UBC Okanagan News, 04 May 2021.
Exoplanet Geology: A Clue to Habitability? by Paul Gilster, Centauri Dreams, 06 May 2021.
Gaia has an introduction and links about how life interacts with a planet.
My mind wanders to a barely related subject. What on Earth gives magnetotactic bacteria a survival advantage? But adrift in nearby space, released by comets, would they be drawn to planets with magnetic fields? Maybe?
| 05 May 2021 |
What'sNEW about HGT |
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...about 8% of human genetic material is derived from human endogenous retroviruses (HERV) that entered the human genetic lineage via retroviral infection of the germline....
"Virus-derived variation in diverse human genomes" by Shohei Kojima et al., PLoS Gen., 26 Apr 2021.
Viruses and HGT has more.
Did COVID-19 arrive with cometary dust and spread around the globe on high winds? This possibility is discussed in a brief preprint by an international team of astrobiologists, immunologists and geneticists. For one argument, explosive surges of the disease at various times in disparate regions are hard to explain with only person-to-person transmission. Rather, the outbreaks look about as unpredictable as the weather. I know these authors well and I agree – this possibility should not be thoughtlessly dismissed.
"Cometary Origin of COVID-19" by Edward J. Steele et al., Xixra, 30 Mar 2021.
"Growing Evidence against Global Infection-Driven by Person-to-Person Transfer of COVID-19" by N Chandra Wickramasinghe et al., Virol Curr Res, Apr 2020.
Comets: The Delivery System has background and related links.
Influenza from Space? has correpondence with updates since 2000.
07 Feb 2018: High winds carry countless viruses around the world.
...the possibility of a biological transfer has practical implications for how we search for evidence of life....
"Life on Mars: Independent Genesis or Common Ancestor?" by Alfonso F. Davila, Astrobiology, 13 Apr 2021.
"Could We Really All Be Martians?" by Dirk Schulze-Makuch, Air & Space, 30 Apr 2021.
Life on Mars! includes a Comparison of predictions.
In all of life there are four standard DNA nucleobases, known by their initials, ATGC. But a few DNA viruses infecting bacteria use an alternate for one of the four: instead of A (adenine) they deploy 2-aminoadenine, designated Z. Like A, Z pairs with T (thymine), but more strongly. Now biologists have identified enzymes that guide its assembly.
"ZTCG: Viruses expand the genetic alphabet" by Michael W. Grome and Farren J. Isaacs, doi:10.1126/science.abh3571, Science, 30 Apr 2021.
"Weird viral DNA spills secrets to biologists" by Ewen Callaway, Nature, 29 Apr 2021.
Intriguingly to us, the Z nucleobase has been detected in carbonaceous meteorites.
"Carbonaceous meteorites contain a wide range of extraterrestrial nucleobases" by Michael P. Callahan et al., doi:10.1073/pnas.1106493108, PNAS, 23 Aug 2011.
| 24 Apr 2021 |
What'sNEW about HGT |
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It's probably an ongoing process happening all the time, and then you're only going to fix one or two.
"Widespread lateral gene transfer among grasses" by Samuel G. S. Hibdige et al., doi:10.1111/nph.17328, New Phytologist, 22 Apr 2021.
"Grasses pass genes from one species to another but ...how" by Michael Marshall, New Scientist, 23 Apr 2021.
...how plants and animals steal genes from other species to accelerate evolution by Luke Dunning, The Conversation +Physorg.com, 23 Apr 2021.
"Widespread occurrence of natural genetic transformation of plants by Agrobacterium" by Tatiana V. Matveeva and Léon Otten, doi:10.1007/s11103-019-00913-y, Plant Molecular Biology, 21 Sep 2019.
Naturally transgenic plant species occur on an unexpectedly large scale.
Viruses and HGT has more.
Richard B. Hoover talks with students about the history of space exploration.
Back to the Moon – and beyond, 1.5 hr powerpoint video, recorded Apr 2021.
Richard Hoover: collected articles
| 15 Apr 2021 |
What'sNEW about HGT | |
Butterflies and moths acquired useful bacterial genes by HGT. After transfer, the genes underwent duplication and divergence to function in carbohydrate metabolism and in the silk gland. May we please acknowledge that cross-kingdom HGT can produce macroevolutionary advances in eukaryotes?
"Horizontal gene transfer and gene duplication of β-fructofuranosidase confer lepidopteran insects metabolic benefits" by Xiangping Dai et al., doi:10.1093/molbev/msab080, Molecular Biology and Evolution, 19 Mar 2021.
Ingenious mechanism for sucrose metabolism in lepidopteran insects Zhejiang University Newsroom, +Mirage News, 15 Apr 2021.
Viruses and HGT has lots more.
This book offers an account of our exploration of Mars since the dawn of the Space Age.... writes planetary scientist Sarah Stewart Johnson. It's also about her personal journey, starting from her childhood fascination with geology and the night sky, then advancing into the world of NASA. As her role there grows, the two threads come together. The science is entertaining, although some episodes disappoint me.
Chapter 4 covers the Viking missions. We learn much about Carl Sagan and something of the hidden politics that damaged his career. We also meet Wolf Vishniac and his proposed experiment nicknamed "Wolftrap" to look for microbial life on Mars. It was dropped, but another experiment flown on Viking detected active bacterial metabolism. 'We were so excited, we sent out and got champagne, cigars,' Gulliver's lead recalled (p 70). Gulliver had become the Labelled Release (LR) experiment, whose leader was Gil Levin. But without turning to the fine print in the endnotes, a reader would never even learn his name.
Chaper 5, "Stone from the Sky" tells the story of the Allen Hills meteorite (ALH84001). In 1996, NASA geologist David S. McKay and co-workers reported that it contained good evidence for past life on Mars. But after much excitement, skepticism took over. Johnson pronounces that neither the LR experiment nor the analysis of ALH84001 produced anything conclusive. Both projects came before her active involvement, so she is likely just relaying NASA's official position. I think it's whitewashed.
By the time Opportunity and Spirit rovers were launched for Mars, Johnson was on the team. Right away, in 2004, Opportunity photographed tiny shapes that clearly resemble fossilized crinoid pieces. She has studied crinoids and she is well aware of that image, but now she ignores it. Later Mars missions like Phoenix and Curiosity didn't include life-detecting experiments. Not even the current one, Perseverance. This intransigence is quite puzzling. Is hidden politics still at work at NASA?
But Johnson's book is really a memoir. She fell in love, she almost died, and she is ever enchanted with the wonders of Mars. Her own story is engaging and the writing excellent. I hope she writes more.
The Sirens of Mars: Searching for Life on Another World by Sarah Stewart Johnson, ISBN:9781101904817, Crown/Penguin Random House, 07 Jul 2020.
Countdown to Mars, 2.5 min. YouTube video with Dr. Sarah Johnson, posted 06 Jul 2020.
Thanks, Mark Frederick at the Memphis bookstore, Novel.
Life on Mars! has background with updates about
Viking and
ALH84001.
Sea Lilies on Ancient Mars: a poster about the fossilized crinoids.
...proof of concept that animal DNA can be collected from air sampling, doi:10.7717/peerj.11030, by Elizabeth L Clare et al., PeerJ, online 31 Mar 2021.
Environmental DNA Can Be Pulled from the Air by Amanda Heidt, TheScientist, 07 Apr 2021.
Genes underlying oxygenic photosynthesis appear to be as old as life. This conclusion follows a deep phylogenetic analysis from biologists in the UK and Australia.
Time-resolved comparative molecular evolution of oxygenic photosynthesis by Thomas Oliver et al., doi:10.1016/j.bbabio.2021.148400, Biochimica et Biophysica Acta (BBA) - Bioenergetics, 01 Jun (online 19 Feb) 2021.
Photosynthesis could be as old as life itself by Hayley Dunning, Imperial College London +ScienceDaily, 16 Mar 2021.
Thanks, Martin Langford.
In mainstream darwinian theory, genetic programs are composed gradually, by trial-and-error. For decades now, around the world, genomicists have been sequencing and cataloging genes, so clear examples of the darwinian process should be abundant. They aren't. Instead, genes seem to come abruptly, whole or in large pieces, as expected in cosmic ancestry. Sometimes the parts arrive long before they are deployed, as it seems here. Many more examples of genes that appear to precede their own deployment are discussed and linked from:
Metazoan Genes Older Than Metazoa?
Genes Older Than Earth?
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