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23 Aug 2017
Improbable Destinies, by Harvard herpetologist Jonathan Losos, asks How predictable is evolution? Would "replaying the tape" produce a completely different outcome, as Stephen Jay Gould famously believed? Or is evolution rampantly "convergent," as Simon Conway Morris supports with many examples?
Improbable Destinies

Losos carefully deconstructs the question and presents evidence for both sides. Early on we get deep into the story of the Burgess shale, whose fossils Conway Morris re-examined with fresh eyes, and which Gould publicised in Wonderful Life (1989). Soon, Losos introduces his own specialty, lizards, and his lifelong study of them. Researches by other evolutionary specialists also pertain the original question, and their personal stories are entertaining.

Losos wants to tackle the question experimentally, so projects like Richard Lenski's years-long culturing of cloned bacteria get close attention. We were delighted to read about the Rothamstead Research Station in England, with some experiments begun more than a century ago. Elsewhere, we especially enjoyed learning about odd species with astonishing features, like the aye-aye of Madagascar, with ever-growing incisors and "an elongate, skeletal middle finger capable of rotating in any directon."

Losos's eventual answer is both — Evolution repeats itself sometimes, but often doesn't. While we enjoyed and recommend the book, we wish the question were treated from a perspective beyond strict darwinism. Most of the evolution probed in detail is micro-evolution, by which we mean evolution attainable with only a few point-mutations, so not forbiddingly improbable. (We were pleased to learn a term for changes requiring no germ-line genetic mutations, "phenotypic plasticity".) When macro-evolution is observed, the genetic changes that may produce it get insufficient attention. Computer models are not mentioned. We wish that evolutionary biologists who are truly curious would ask this question: Where do new genetic programs come from?

Improbable Destinies: Fate, Chance, and the Future of Evolution, by Jonathan B. Losos, 384 pages, Riverhead Books, 08 Aug 2017.
> Neo-Darwinism: The Current Paradigm has sections about Punctuated Equilibrium and Convergent Evolution.
> Macroevolutionary Progress Redefined... considers micro- and macro-evolution.

14 Aug 2017
The implication is that once species become technological, they flame out and take the biosphere with them.
A mathematical astronomer from Arkansas proposes a plausible and sobering solution to Fermi's paradox:
Here we argue that ...the typical technological species becomes extinct soon after attaining a modern technology and that this event results in the extinction of the planet's global biosphere.
Implication of our technological species being first and early by Daniel P. Whitmire, International Journal of Astrobiology, online 03 Aug 2017 (+alternate with author's summary).
The Implications of Cosmic Silence, University of Arkansas (+Newswise), 11 Aug 2017.
> Gaia has more about the longterm fate of living planets.

07 Aug 2017
The possibility of life on Saturn's moon Enceladus drew increased interest in 2005, when NASA's Cassini mission observed a large plume of material erupting from the south polar terrain of Enceladus, sourced within a subsurface ocean of salty liquid water laced with organic compounds.... Now, as the Cassini mission is ending, Astrobiolgy devotes its current issue to the topic. Carolyn Porco's linked article introduces a dozen others, many available online. The photo from Cassini shows Enceladus above Saturn's rings. Enceldaus and Saturn's rings
A Community Grows around the Geysering World of Enceladus by Carolyn C. Porco, doi:10.1089/ast.2017.1711, Astrobiology, online 25 Jul 2017. > Life on Europa, Other Moons, Other Planets?... has related links.

27 Jul 2017
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.

27 Jul 2017
Staphylococcus aureus 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. This surprise, we suggest, adds evidence 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.

26 Jul 2017
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 traffic would increase 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 Thanks, George Nickas.

15 Jul 2017 What'sNEW about HGT |
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.
> Viruses and Other Gene Transfer Mechanisms has much more about HGT.

CRISPR-Cas in bacterium
06 Jul 2017
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.


Space dust collector
04 Jul 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 Thanks, Chandra Wickramasinghe and Martin Langford.
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