Our origins are much less local than we previously thought.
The Cosmic Baryon Cycle and Galaxy Mass Assembly in the FIRE Simulations by Daniel Anglés-Alcázar et al., arXiv:1610.08523 [astro-ph.GA], arXiv, subm. 26 Oct 2016.
Milky Way's Origins Are Not What They Seem, by M. Fellman, Northwestern University (+Newswise), 26 Jul 2017.
Given how much of the matter out of which we formed may have come from other galaxies, we could consider ourselves space travelers or extragalactic immigrants.
Geneticists in Scotland have observed that Staphylococcus aureus (pictured) acquired the gene that confers resistance to methicillin in the mid-1940s. But this antibiotic did not enter medical practice until 1959. The researchers must suppose that other earlier drugs somehow induced the bacteria to select for strains with this gene. Even if so, apparently, the gene was already there. Although this would likely exemplify only microevolution, it supports our contention that genes come first.
Methicillin-resistant Staphylococcus aureus emerged long before the introduction of methicillin into clinical practice by Catriona P. Harkins et al., doi:10.1186/s13059-017-1252-9, Genome Biology, 20 Jul 2017.
Methicillin resistance was out there before methicillin, Nature Research Highlights, 24 Jul 2017.
Metazoan Genes Older Than Metazoa? and Genes Older Than Earth? are related local webpages.
The existence of so many more long-period comets than predicted suggests that more of them have likely impacted planets, delivering icy materials from the outer reaches of the solar system.
It apears that there is much more cometary material in the Oort Cloud than previously known. Their orbits place these large comets in interstellar space, where they might stray to and from orbits around other nearby stars. This increases the likelihood of interstellar panspermia.
Large, Distant Comets More Common Than Previously Thought, Jet Propulsion Laboratory, NASA, 25 Jul 2017.
Debiasing the NEOWISE Cryogenic Mission Comet Populations by James M. Bauer et al., n 2, v 154, The Astronomical Journal, 14 Jul 2017.
Comets: The Delivery System has more.
Thanks, George Nickas.
Several studies have suggested that TE [transposable element] insertions have contributed to the rewiring and evolution of regulatory networks by recruiting multiple genes into the same regulatory circuit. That would well exemplify the robust software management that cosmic ancestry requires. And if the TEs are imported, as by viruses, this would mean that the transfer of genetic material (HGT) is even more imortant for evolution than we knew. Now a comprehensive new study from Japan lists, categorizes and probes many examples of regulatory elements derived from HERVs:
Systematic identification and characterization of regulatory elements derived from human endogenous retroviruses by Ito J, Sugimoto R, Nakaoka H, Yamada S, Kimura T, Hayano T, et al., doi:10.1371/journal.pgen.1006883, PLoS Genet, uncorrected proof online 12 Jul 2017.
|15 Jul 2017
||What'sNEW about HGT ||
Viruses and Other Gene Transfer Mechanisms has much more about HGT.
How bacteria remember and defend against harmful viruses has been observed at almost atomic resolution. The system has redundant, precise safety mechanisms. Seen in detail, it is another feature of life that seems to have come from nowhere.
The [bacterial] immunity system works just as efficiently as ours, except our system functions at the protein recognition level, whereas CRISPR works at the nucleic acid recognition level — Ailong Ke, professor of molecular biology and genetics, Cornell University
Bringing bacteria's defense into focus by Bill Steele, Cornell Chronicle (+Newswise), 30 Jun 2017.
Did Life on Earth Come From Outer Space? by Daniel Oberhaus, Motherboard, 01 Jul 2017.
The image shows an aerogel array for collecting dust on NASA's Stardust mission.
Thanks, Chandra Wickramasinghe and Martin Langford.