Earth's deep life suggests microbes might inhabit the subsurface of other planets. This observation follows the Deep Carbon Observatory's long study of samples from hundreds of boreholes 2.5 to 5 km deep under the continents and oceans. The bacterial and archaeal life there can withstand even higher temperatures and pressures than we knew, and can take nutrients from rocks, with slower metabolism than surface microbes'. The variety and volume of this life is especially srprising. Barely living "zombie" bacteria and other forms of life constitute an immense amount of carbon deep within Earth's subsurface—245 to 385 times greater than the carbon mass of all humans on the surface, according to scientists nearing the end of a 10-year international collaboration....
Life in Deep Earth Totals 15 to 23 Billion Tonnes of Carbon..., the Deep Carbon Observatory, 10 Dec 2018.
Scientists identify vast underground ecosystem containing billions of micro-organisms by Jonathan Watts, The Guardian, 10 Dec 2018.
Thanks, George Nickas.
Bacteria: The Space Colonists has related information and links
Mature Extraterrestrial Biology in Astrophysical Phenomena: Edward J. Steele et al. reply to critical numerical analysis of R Duggleby on "Cause of Cambrian Explosion: Terrestrial or Cosmic?" (Open Access alternate), Progress in Biophysics and Molecular Biology, online 09 Nov 2018.
21 Mar 2018: links to original article by Steele et al.
We hypothesize that the interplay of NHEJ [nonhomologous end-joining] and retroelements may have played a previously unappreciated role in the evolution of advanced life. Ten physicists at the University of Illinois, Urbana-Champaign, say this after phylogenetic experiments in which retroelements, including human ones, were transferred into bacteria. Among their conclusions, proliferation of retroelements in eukaryotes and subsequent addition of complexity to the eukaryotic genome may have been enabled by precise tuning of parameters, leading to suppression of growth defects and enhancement of integration efficiency.
|04 Dec 2018
||What'sNEW about HGT ||
Testing the retroelement invasion hypothesis for the emergence of the ancestral eukaryotic cell by Gloria Lee et al., doi:10.1073/pnas.1807709115, PNAS, 04 Dec 2018.
These physicists are also darwinists, but unconventional ones, like coauthor Nigel Goldenfeld. Here they suggest a new path by which eukaryotes may have evolved from prokaryotes. We think their related observations – that the integration of retroelements contributes to eukaryotic complexity, and that introns may have a constructive role in evolution – also support an amendment to darwinism even more fundamental than they openly contemplate.For understanding evolution, we continue to advocate quarantined experiments that could demonstrate sustainable macroevolutionary progress. Success in the experiments, even in computer simulations, would supply needed proof for the darwinian paradigm; failure might allow consideration of new alternatives.
Viruses... and Introns... are related CA webpages.
Nigel Goldenfeld is the subject of a posting, 01 Sep 2017.
Testing Darwinism... and The Evolution Prize introduce our advocacy of quarantined experiments.
Multimicrobial Kombucha Culture Tolerates Mars-Like Conditions Simulated on Low-Earth Orbit by Olga Podolich et al., Astrobiology, online 28 Nov 2018.
Bacteria... has more about the hardiness of prokaryotes.
The entire galaxy would then be a single connected biosphere sharing the same biochemistry and a cosmic genetic endowment.
Comets, Enceladus and panspermia by N.C. Wickramasinghe, Dayal T. Wickramasinghe and Edward J. Steele, doi:10.1007/s10509-018-3465-0, Astrophys Space Sci, accepted 30 Oct 2018. (Use down arrow, bottom right.)
Remarkably, both [mite] genomes exhibited evidence of ancient lateral gene transfer from soil-derived bacteria or fungi. The transferred genes confer functions that are rare in animals.... The case for lateral or horizontal gene transfer (HGT) across all of life is again reinforced.
|20 Nov 2018
||What'sNEW about HGT ||
Mite genomes reveal 'mighty surprising' fragrant and colourful secrets, University of Liverpool (+PhysOrg.com), 19 Nov 2018; re:
Genomes of trombidid mites reveal novel predicted allergens and laterally-transferred genes associated with secondary metabolism by Xiaofeng Dong et al., GigaScience, 15 Nov 2018.
Viruses... has background and ~1,000 links related to HGT.
The NASA Roadmap to Ocean Worlds by Amanda R. Hendrix et al., Astrobiology, online 13 Oct 2018.
Life on Europa, Other Moons, Other Planets? has links about possible life on the same ocean worlds and more.
Two astrobiologists consider the Drake equation's 4th term, the fraction of habitable planets which develop life. Among their observations is an understatement.
|if a reproducible experiment could produce abiogenesis, information gain regarding the origin of life would be very large|
On the Rate of Abiogenesis from a Bayesian Informatics Perspective by Jingjing Chen and David Kipping, Astrobiology, online 31 Oct (+arXiv.org, 21 Jun) 2018.
The RNA World and The Second Law... have related discussion.
Sharing life with the planets next door by Starre Vartan, Astrobiology Magazine (+PhysOrg.com), 29 Oct 2018; re:
Dynamical and Biological Panspermia Constraints Within Multiplanet Exosystems by Dimitri Veras et al., doi:10.1089/ast.2017.1786, Astrobiology, online 12 Sep 2018.
Thanks, Google Alerts.
The lateral transfer of bacterial genes by viruses can be 1000-fold more effective than previously known, when mutliple transducing phages carrying only bacterial DNA are released to infect other cells.
|28 Oct 2018
||What'sNEW about HGT ||
Genome hypermobility by lateral transduction by John Chen et al., doi:10.1126/science.aat5867, Science, 12 Oct 2018.
A common trick for transferring bacterial DNA by Alan R. Davidson, Science, 12 Oct 2018.
Viruses and Other Gene Transfer Mechanisms has background and many links related to HGT.
Results from the Japanese mission Tanpopo "support the panspermia hypothesis."
Survival Data of Deinococcus aetherius from ...the International Space Station... by Akihiko Yamagishi et al., Astrobiology, online 05 Oct 2018.
Can The Theory Be Tested? has related links, including
11 Mar 2010: about Tanpopo.
Life could potentially be exchanged over thousands of light-years.
Cometlike objects could be spreading life ...throughout the Milky Way by George Musser, Science, 15 Oct 2018.
Implications of Captured Interstellar Objects for Panspermia and Extraterrestrial Life by Manasvi Lingam and Abraham Loeb, The Astronomical Journal, 12 Oct 2018.
Thanks, Sascha Wageringel.
...we show that panspermia is not exclusively relegated to solar-system sized scales, and the entire Milky Way could potentially be exchanging biotic components across vast distances.
Harvard astrophysicists observe that objects like comets, asteroids or even planets can be spun away from the galactic center at velocities sufficient to reach the intergalactic medium. Considering the likely distribution of numerous variables in a fashion reminding us of the Drake equation, they firmly conclude, panspermia is viable on galactic scales.
Galactic Panspermia by Idan Ginsburg, Manasvi Lingam and Abraham Loeb, preprint on arXiv.org, 11 Oct 2018, and
v 868, The Astrophysical Journal Letters, 19 Nov 2018.
The Milky Way Could Be Spreading Life From Star to Star by Matt Williams, Universe Today, 12 Oct 2018.
09 Feb 2018: a related notice from Lingam and Loeb. Also see
01 Nov 2017: about an interstellar traveler.
Introduction... has background.
Comets... is related.
Thanks, twice, Google Alerts.
Elegant and precise genetic programs guide the forces that allow seemingly identical starting cells to develop into highly specialized entities.... This comment comes, in a special issue of Science, in the introduction to eight articles about newly observed systems essential for controlling metazoan development. These systems utilize, for example, chromatin plasticity (illustration from Yadav et al.), dynamic DNA methylation, developmental enhancers guided by chromosome topology, and "sequence-dependent stochastic switching at regulatory loci".
Standard darwinism, by its logic, must eventually account for the origins of these systems, but no such accounts are yet even suggested. (To our surprise, a browser search for the case-insensitive string darwin found no matches in any of the nine related articles.) Meanwhile, elegant and precise genetic programs controlling development would further exemplify the robust software management that genomes require in cosmic ancestry.
Forces behind form by Beverly A. Purnell, Steve Mao and Laura M. Zahn, Science, 28 Sep 2018.
Robust Software Management in Genomes: this page is incomplete and under construction.
Another project to explain the origin of life is announced. We will watch for any breakthroughs.
Ground-breaking lab poised to unlock the mystery of the origins of life on Earth and beyond, McMaster University (+Newswise), 04 Oct 2018.
The RNA World
and Other Origin-of-Life Theories has background and links.
Cyanobacteria thrive in the deep continental subsurface without light or oxygen. They could probably do as well in similar places on other planets or moons. So say sixteen astro- and molecular biologists after finding cyanobacteria-dominated communities deep in southwestern Spain, in rock formations analogous to ones on Mars.
...their unequivocal presence in samples from this and other studies ...increases their relevance in early life and astrobiological scenarios.
Viable cyanobacteria in the deep continental subsurface by F. Puente-Sánchez et al., doi:10.1073/pnas.1808176115, PNAS, online 01 Oct 2018.Meanwhile, a concurrent survey reports evidence of "the deep biosphere" from ten locations around the world.
The chart illustrates the metbolic pathways deployed by cyanobacteria from two samples. Oxygen-dependent and photosynthetic paths are crossed out, to indicate that they are useless.
Surprise Life Found Thriving 2,000 Feet Underground by Maya Wei-Haas, National Geographic, 01 Oct 2018.
Bacteria: The Space Colonists has lots more about their survival capabilities.
Life on Mars! has additional evidence.
Thanks, Robert Sweeney, Martin Langford, and Richard Hoover, who emails, ...These are the same genera of Cyanobacteria that Alexei [Rozanov] and I have often found embedded in freshly fractured interior surfaces of the Orgueil CI1 and Murchison CM2 Carbonaceous meteorites. See, for example
Fossilized bacteria..., posted 03 Mar 2011.
Life Thrives Within the Earth's Crust by Catherine Offord, The Scientist, 01 Oct 2018.
Green algae stole genes from bacteria to survive in harsh environments....
|01 Oct 2018
||What'sNEW about HGT ||
How Some Algae May Survive Climate Change, Rutgers Today (+Newswise), 27 Sep 2018.
Genomic Analysis of Picochlorum Species Reveals How Microalgae May Adapt to Variable Environments by Fatima Foflonker et al., Molecular Biology and Evolution, 01 Sep 2018.
Viruses and Other Gene Transfer Mechanisms has background with many recent & older links related to HGT.