Alien comets may be common... by W. Wayt Gibbs, Science, 01 Nov 2016.
...interstellar comet contains alien water by Alexandra Witze, Nature, 30 Oct 2016.
Comets: The Delivery System has background and updated links.
19 Oct & 13 Sep: more about 2I/Borisov.
...singlecelled organisms (protozoa and even bacteria) have homologs of neuronal developmental genes. The functions of these molecules in organisms without neurons is unknown.... William Kristan, Neurobiology, UC Davis
Early evolution of neurons by William B. Kristan Jr., Current Biology, 24 Oct 2016.
Thanks, Kenneth Augustyn.
Metazoan Genes Older Than Metazoa? has related links since 1996.
Genes Older Than Earth? deserves a look.
Exporting Terrestrial Life Out of the Solar System with Gravitational Slingshots of Earthgrazing Bodies by Amir Siraj and Abraham Loeb, ArXiv, 14 Oct 2019; and commentary:
Comets and Interstellar Objects Could be Exporting Earth Life Out into the Milky Way by Matt Williams, Universe Today, 19 Oct 2019.
Thanks, Google Alerts.
Introduction... has history.
...New Questions describes types of panspermia.
19 Oct: an interstellar comet.
Genes-in-waiting is one way to describe de novo genes, the ones that come from silent, so-called "junk" DNA. Now, they are observed everywhere. In the past five years, researchers have found numerous signs of these newly minted 'de novo' genes in every lineage they have surveyed. These include model organisms such as fruit flies and mice, important crop plants and humans.... Apparently already programmed, they need only to be turned on, bypassing the lengthy trial-and-error process that standard darwinism requires. Until recently, this was thought impossible, because the chance that lengthy strands of random DNA might luckily have programmatic meaning is effectively zero. The discovery that they are common supports our prediction that genes precede their deployment.
Three New Human Genes and De Novo Genes in General, first posted 2009, has discussion and updated links.
...genes do not always evolve from existing ones, as biologists long supposed. Instead, some are fashioned from desolate stretches of the genome that do not code for any functional molecules.|
Genes from the Junkyard (print edition title) by Adam Levy, p 314 v 574 Nature, 17 Oct 2019.
The Hubble Telescope observed interstellar comet 2I/Borisov for seven hours. In a time-lapse movie compressed into two seconds, the comet seems motionless as background stars streak by. Its high velocity indicates that it comes from beyond the solar system and will leave again for interstellar space. Cometary panspermia between stars is entirely possible! (A substantial fraction of the Oort cloud likely consists of comets from nearby stars.)
Hubble Observes First Confirmed Interstellar Comet | video, Space Telescope Science Institute, 16 Oct 2019.
Comets: The Delivery System has history and updates.
Thanks, Newswise and Rob Cooper.
I'm Convinced We Found Evidence of Life on Mars in the 1970s by Gilbert V. Levin, Scientific American, 10 Oct 2019.
Life on Mars! has more about the Viking LR experiments.
Thanks, Ted Steele and William Smith.
...a group of yeasts ...have lost part of the vitamin B1 biosynthetic pathway in the past but have managed to rebuild it by capturing multiple genes from bacteria through horizontal gene transfer (HGT).
|14 Oct 2019||What'sNEW about HGT |
Multilayered horizontal operon transfers from bacteria reconstruct a thiamine salvage pathway in yeasts by Carla Gonçalves and Paula Gonçalves, PNAS, online 14 Oct 2019.
The adaptation of the newly acquired operons to the eukaryotic setting involved a repertoire of mechanisms until now only sparsely documented, namely longer intergenic regions, post-horizontal gene transfer (HGT) gene fusions fostering coordinated expression, gene relocation, and possibly recombination generating mosaic genes. The results provide additional evidence that HGT occurred recurrently in this yeast lineage and was crucial for the reestablishment of lost functions and that similar mechanisms are used across a broad range of eukaryotic microbes....
Viruses... has more about HGT
Robust Software Management... (incomplete) considers a repertoire of mechanisms.
The cholera bacterium can steal up to 150 genes in one go, Ecole Polytechnique Fédérale de Lausanne, 26 Sep 2019.
|09 Oct 2019||What'sNEW about HGT ||
...the transfer of large genomic regions in Vibrio cholerae by Noémie Matthey et al., elife, 03 Sep 2019.
Viruses and Other Gene Transfer Mechanisms has related examples.
Mankind must keep searching for life on Mars by Chandra Wickramasinghe, The Sunday Telegraph, 06 Oct 2019.
Life on Mars! cites evidence since 1996.
Chandra Wickramasinghe has more about him.