What'sNEW
...one of the most promising habitable zone exoplanet candidates known, 48 lightyears away, is seen with the Webb Space Telescope. Larger than Earth, in the "Goldilocks Zone" of a red dwarf star, its density suggests it is 10 to 20 percent water. If so, it likely harbors an ice-covered ocean, and, if tidally locked, its sunny side could even have open water. Might it resemble an eyeball?!
 "Found with Webb: a potentially habitable world," University of Montreal, +PhysOrg, 08 Jul 2024; re:
"Transmission Spectroscopy of the Habitable Zone Exoplanet LHS 1140 b with JWST/NIRISS," by Charles Cadieux et al, arXiv:2406.15136 [astro-ph.EP] 21 Jun 2024.
 Life on Europa, Other Moons, Other Planets? has related links.
| 07 Jul 2024 |
What'sNEW about HGT
|
Overall, Mycena show highly unusual, varied mosaic-like genomic structures adaptable to multiple lifestyles, providing genomic illustration for the growing realization that fungal niche adaptations can be far more fluid than traditionally believed.
An international team has sequenced the genomes of 24 species of "bonnet" mushrooms as part of the 1000 Fungal Genomes project. They found that the genomes of three Arctic ones were especially large. Gene duplications, TE insertions, HGT and de novo and orphan genes all apparently contributed to the genome expansions. Many of the extra genes, although conserved across several species, are silent, and most of them are unrecognized. To explain these surprises, new corrolaries to neo-Darwinian theory are considered.
"Extreme overall mushroom genome expansion in Mycena s.s. irrespective of plant hosts or substrate specializations," by Christoffer Bugge Harder et al, doi:10.1016/j.xgen.2024.100586, Cell Genomics, 27 Jun 2024.
"Genetic Giants: Unveiling the Massive Genomes of Arctic's Glow-in-the-Dark Mushrooms," SciTechDaily, 27 Jun 2024.
In cosmic ancestry, unnecesary genes, genes-in-waiting, unfamiliar, orphan and de novo genes are expected. Evolution can make significant steps when robust software management "tinkers" with existing, available programming such as that. This latter suggestion even gets inferential support in the new study: TE insertions were seen to be especially active around transcription factors, which can turn genes on-or-off. The study is comprehensive and very deep.
Viruses and Other Gene Transfer Mechanisms has lots about HGT.
Robust Software Management introduces this concept and the need for it.
The history of life on Earth is the history of life's remaking Earth.
"The Mysterious, Deep-Dwelling Microbes That Sculpt Our Planet," by Ferris Jabr, The New York Times, 24 Jun 2024.
Gaia and James Lovelock are well endorsed by Jabr.
Bacteria... discusses their surprising range and engineering capability..
On Earth, dimethylsulfide (DMS) is produced exclusively by biological metabolism. That's why Carl Sagan thought it might be a good "biomarker" — if seen in an extraterrestrial environment, a positive sign that biology exists there. Now its presence on comet 67P/Churyumov-Gerasimenko has been confirmed, after two years of close inspection with a high-resolution mass spectrometer aboard the Rosetta spacecraft. This detection was the subject of a paper by five astrobiologists in a session titled, "Rocky planets, moons, and minor bodies: Evolution, characterization and astrobiological implications," at a conference of the European Geophysical Union (EGU), in Vienna, Austria, two months ago.
Their reaction leaves me dumbfounded. Before the evience is in, they already know where life is and isn't: But what if this biomarker is present in the completely abiotic cometary matter? ...Our detailed analysis of the sulfur-bearing hydrocarbon signals detectable in 67P's coma yields strong evidence for the presence of DMS and thus provides the basis to argue that this molecule might not be a robust indicator of extraterrestrial life.
"Is dimethylsulfide a good biomarker?" by Nora Hänni et al. [abstract], EGU General Assembly 2024, 14-19 Apr 2024.
 Thanks, Richard B. Hoover.
12 Sep 2023: Another detection of extraterrestrial DMS.
03 Oct 2017: A different biomarker is seen (also on 67P) and then delisted.
![]()
|