COSMIC ANCESTRY | Quick Guide | What'sNEW - Later - Earlier - Index


15 May 2018
...many genes typically associated with metazoan functions actually pre-date animals themselves.... This casual observation comes in the preface to an extensive computer-driven analysis of metazoan ancestral genes. The thesis of the study, by two British zoologists, is ...the ancestral metazoan genome included a remarkable 1189 Novel HG [homology groups].... The Novel HG comprise 19% of the total HG in the first metazoan....

To them the novel ones imply that the transition was accompanied by an increase of genomic innovation, including many new, divergent, and subsequently ubiquitous genes encoding regulatory functions associated with animal multicellularity. ...There are two alternative scenarios that could explain these patterns.... The first ...would imply an extended 'stew' in which the molecular components of animal biology were assembled. ...The second possibility involves many new genes emerging during a short 'popcorn' stage....

What we find remarkable is that neither the genes that apparently predate animals, nor the novel ones noticed now (quantified by green numbers at every stage in the phylogeny below), have any discernable darwinian provenance. For the novel ones, the "extended stew" has no direct supporting evidence, and the "popcorn stage" has no credible mechanism. None of it makes darwinian sense. But genes that come first, and genes without darwinian provenance are standing predictions of cosmic ancestry.
Metazoan novel homology groups
Reconstruction of the ancestral metazoan genome reveals an increase in genomic novelty by Jordi Paps and Peter W. H. Holland, doi:10.1038/s41467-018-04136-5, Nature Communications, 30 Apr 2018.
The Very First Animal Appeared Amid an Explosion of DNA by Carl Zimmer, The New York Times, 04 May 2018.
Metazoan Genes Older Than Metazoa? and Genes Older Than Earth? discuss genes that come first.
New genetic programs... predicts genes that "seem to have come from nowhere."
Three New Human Genes is about de novo genes, the ones with recognizable precursors that were silent, non-functional, aka "junk" sequences. (If that's a provenance, it is not darwinian.) Thanks Thanks, Genevieve Christy.

Update, 10 May 2018: new insight pertaining to A fossil on Mars resembles one on Earth, posted 28 Oct 2015.

Caenorhabditis elegans Tolerates Hyperaccelerations up to 400,000 x g, de Souza Tiago Alves Jorge and Pereira Tiago Campos, doi:10.1089/ast.2017.1802, Astrobiology, online 10 May 2018.

Exoplanet Biosignatures: A Review of Remotely Detectable Signs of Life by Edward W. Schwieterman et al., doi:10.1089/ast.2017.1729, Astrobiology, online 04 May 2018.

05 May 2018 What'sNEW about HGT |
A newly sequenced giant marine virus A newly sequenced giant marine virus, TetV, has 663 predicted genes, 435 of which resemble none previously known. More than a hundred encode eukaryotic proteins with close homologs among plants and green algae that the virus infects. Of the rest, 45 are most simlar to to bacterial genes, and 63 to genes found in other viruses (see figure). TetV has a 668-kb dsDNA circular genome.

What are the eukaryotic and bacterial genes doing there? And where do so many unfamiliar genes keep coming from? What purpose could they serve? And why do the only ten tRNA genes in the genome lie consecutively along one strand of 879 nucleotides? None of this makes any darwinian sense, but similar evidence is commonplace.

We think alternatives more congruent with the evidence deserve consideration. Of course, horizontal gene transfer (HGT) well explains the close homology between virus and host genes. And cosmic ancestry would give the anomolous genes a reason for being there.

A giant virus infecting green algae encodes key fermentation genes by Christopher R. Schvarcz and Grieg F. Steward, doi:10.1016/j.virol.2018.03.010, Virology, May 2018.
A new giant virus found in the waters off Oahu, University of Hawaii at Manoa (+ScienceDaily), 03 May 2018.
Viruses... lists many related examples. Thanks Thanks, Martin Langford.

03 May 2018
...this type of organism is of significant interest to the search for past or present life on the Red Planet.
Microbes Living in a Toxic Volcanic Lake Could Hold Clues to Life on Mars, University of Colorado Boulder via Newswise, 02 May 2018, re:
Lack of Microbial Diversity in an Extreme Mars Analog Setting: Poás Volcano, Costa Rica by Brian M. Hynek et al., doi:10.1089/ast.2017.1719, Astrobiology, online 24 Apr 2018.
Bacteria... has more about extremophiles. Life on Mars! is related.

02 May 2018 What'sNEW about HGT |
...Steamer-like elements are present in the genomes of completely unrelated organisms, including zebrafish, sea urchin, acorn worms, and coral. Phylogenetic incongruity, a patchy distribution, and a higher similarity than would be expected by vertical inheritance all provide evidence for multiple long-distance cross-phyla horizontal transfer events. These data suggest that over both short- and long-term evolutionary timescales, Steamer-like retrotransposons, much like retroviruses, can move between organisms and integrate new copies into new host genomes. Horizontal transfer of retrotransposons between bivalves and other aquatic species of multiple phyla by Michael J. Metzger et al., doi:10.1073/pnas.1717227115, PNAS, 01 May 2018.
In cosmic ancestry, horizontal gene transfer (HGT) is essential for evolutionary progress. The importance of HGT among prokaryotes is now well-accepted. And among eukaryotes, the evidence has become hard to dismiss.
Viruses... has background and What'sNEW links to hundreds of other examples of HGT benefitting eukaryotes.

Leave Mars to the robots by David Weintraub, LA, accessed 29 Apr 2018. Thanks Thanks, Bob Sweeney.

Mars Trace Gas Orbiter
26 Apr 2018 is natural to ask whether methane on Mars is also of biologic origin.
Mars probe poised to solve red planet's methane mystery, Nature News, 23 Apr 2018.
The results indicate that methanogens could survive on Mars as it exists today....
Survival of non-psychrophilic methanogens exposed to martian diurnal and 48-h temperature cycles by R.L.Mickol et al., Planetary and Space Science, online 21 Mar 2018, and commentary: ...Some Types of Life Can Survive Conditions Found on Mars, University of Arkansas (+Newswise), 23 Apr 2018. Life on Mars! has more about methane there.

25 Apr 2018
...a brief history of panspermia and ...the return of panspermia by Stephen Fleischfresser, Cosmos, 24 Apr 2018, re: ...Terrestrial or Cosmic? by Steele et al., linked 21 Mar 2018.

16 Apr 2018
What signature would our civilization leave in the fossil record? This seemingly gratuitous question is more consequential than it appears, as we learn in a deep analysis by an astrophysicist and an astrobiologist. Of special interest to us, a long-extinct advanced civilization on one of our neighboring planets might be hard to notice.
+ ocean sediment ...the Anthropocene will likely only appear as a section a few cm thick....
+ Conceivably, deep drilling operations could be carried out on [Venus or Mars in the] future to assess their geological history. This would constrain consideration of what the fingerprint might be of life, and even organized civilization.
+ While we strongly doubt that any previous industrial civilization existed [on Earth] before our own, asking the question in a formal way that articulates explicitly what evidence for such a civilization might look like raises its own useful questions related both to astrobiology and to Anthropocene studies.

The Silurian Hypothesis: Would it be possible to detect an industrial civilization in the geological record? by Gavin A. Schmidt and Adam Frank, arXiv:1804.03748 [astro-ph.EP], online 10 Apr 2018.
The Atlantic + It would be easy, therefore, to miss an industrial civilization that only lasted 100,000 years—which would be 500 times longer than our industrial civilization has made it so far.
Was There a Civilization On Earth Before Humans? by Adam Frank, The Atlantic, 13 Apr 2018. Thanks Thanks, Nature Briefing, Bob Sweeney, George Nickas and Stumble Upon.
Civilization Before Homo Sapiens?, commentary by Paul Gilster, Centauri Dreams, 18 Apr 2018.
How Would We Know...?, commentary by Charles Q. Choi, LiveScience, 18 Apr 2018.

13 Apr 2018
Hypersaline subglacial lake ...these previously unknown hypersaline subglacial lakes ...are compelling analogs for potential ice-covered brine lakes and lenses on planetary bodies....
Discovery of a hypersaline subglacial lake complex beneath Devon Ice Cap, Canadian Arctic by Anja Rutishauser et al., Science Advances, 11 Apr 2018.
...the lakes may have been sealed off ...for up to 120,000 years.
Isolated lakes found beneath Canadian ice sheet by Mary Halton, BBC News, 12 Apr 2018. Thanks Thanks, Bob Sweeney.
Life on Europa, Other Moons, Other Planets? and Earth-analogs for those environments has related links.

13 Apr 2018
The Economist Seeding alien worlds with terrestrial life is now being discussed
Colonising the galaxy is hard. Why not send bacteria instead? The Economist, 12 Apr 2018.
Panspermia Asks New Questions mentions directed panspermia among other varieties.

March Astrobiology cover
11 Apr 2018
...another, hitherto unrecognized environment is proposed as a site for the origin of life on Earth.
A Hydrothermal-Sedimentary Context for the Origin of Life by F. Westall et al., Astrobiology, 01 Mar 2018. The RNA World... has background and links about Origin-of-Life theories. These no longer deal with the software problem. Even the hardware problem is sometimes set aside while a conducive environment is suggested, as by Westall et al.

04 Apr 2018 What'sNEW about HGT |
Graph of CREs
Transposable elements are the primary source of novelty in primate gene regulation by Marco Trizzino et al., Genome Res., online 30 Aug 2017.
Human Genome Search and New genetic programs... describe a research project to learn if most new human genes come from horizontal gene transfer (HGT). Since transposons are likely installed by viruses, we think Trizzino et al. support the HGT hypothesis.
Viruses and Other Gene Transfer Mechanisms is the main related local webpage.
COSMIC ANCESTRY | Quick Guide | Site Search | What'sNEW - Later - Earlier - Index | by Brig Klyce | All Rights Reserved