Entries in biology (2)

Saturday
Mar052011

Possible (Likely?) Fossils Found in Meteorites

3/15/2011 Update -  The peer reviews are rolling in and it’s not looking definitive one way or another for these alien fossils.  Some reviewers were quick to accept the finding; perhaps too quick for such a significant claim.  Others urge caution and further analysis, and that’s what we should expect going forward.

The blogosphere panned the paper because the website on which it appears looks like it was designed in 1995.  While true, this “argument” is a red herring.  Should we stop listening to or trusting Leo “The Tech Guy” Laporte because his website looks equally arcane?  Of course not.

Viva science!

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This is one of the biggest finds in astrobiology since the Murchison meteorite and it could be one of the biggest scientific discoveries ever.  It may also be the most vetted paper of all time, with over 100 reviewers.

The find lends support to the idea of panspermia, the hypothesis that life on Earth originated elsewhere and was carried here on meteors or comets.

I’ve reproduced the abstract below; see the whole thing in the Journal of Cosmology.

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Fossils of Cyanobacteria in CI1 Carbonaceous Meteorites:
Implications to Life on Comets, Europa, and Enceladus

Richard B. Hoover, Ph.D.
NASA/Marshall Space Flight Center, Huntsville, AL


Abstract

Environmental (ESEM) and Field Emission Scanning Electron Microscopy (FESEM) investigations of the internal surfaces of the CI1 Carbonaceous Meteorites have yielded images of large complex filaments. The filaments have been observed to be embedded in freshly fractured internal surfaces of the stones. They exhibit features (e.g., the size and size ranges of the internal cells and their location and arrangement within sheaths) that are diagnostic of known genera and species of trichomic cyanobacteria and other trichomic prokaryotes such as the filamentous sulfur bacteria. ESEM and FESEM studies of living and fossil cyanobacteria show similar features in uniseriate and multiseriate, branched or unbranched, isodiametric or tapered, polarized or unpolarized filaments with trichomes encased within thin or thick external sheaths. Filaments found in the CI1 meteorites have also been detected that exhibit structures consistent with the specialized cells and structures used by cyanobacteria for reproduction (baeocytes, akinetes and hormogonia), nitrogen fixation (basal, intercalary or apical heterocysts) and attachment or motility (fimbriae). Energy dispersive X-ray Spectroscopy (EDS) studies indicate that the meteorite filaments are typically carbon rich sheaths infilled with magnesium sulfate and other minerals characteristic of the CI1 carbonaceous meteorites. The size, structure, detailed morphological characteristics and chemical compositions of the meteorite filaments are not consistent with known species of minerals. The nitrogen content of the meteorite filaments are almost always below the detection limit of the EDS detector. EDS analysis of terrestrial minerals and biological materials (e.g., fibrous epsomite, filamentous cyanobacteria; mummy and mammoth hair/tissues, and fossils of cyanobacteria, trilobites, insects in amber) indicate that nitrogen remains detectable in biological materials for thousands of years but is undetectable in the ancient fossils. These studies have led to the conclusion that the filaments found in the CI1 carbonaceous meteorites are indigenous fossils rather than modern terrestrial biological contaminants that entered the meteorites after arrival on Earth. The δ13C and D/H content of amino acids and other organics found in these stones are shown to be consistent with the interpretation that comets represent the parent bodies of the CI1 carbonaceous meteorites. The implications of the detection of fossils of cyanobacteria in the CI1 meteorites to the possibility of life on comets, Europa and Enceladus are discussed. Keywords: Origins of life, CI1 meteorites, Orgueil, Alais Ivuna, microfossils, cyanobacteria, comets, Europa, Enceladus

Sunday
Apr252010

Oxytocin — The Chemical That Will Make You Trust Everyone

I must have high levels of circulating oxytocin, because I’ve trusted to a fault many times and I’m terrible at holding a grudge.  I suppose I’d rather have it this way than be afraid everyone was always trying to get over on me.  On the other hand, I’m a pretty hardcore skeptic…how does that work?  From Dvorak Uncensored / NPR:

[Over] the past 10 years, oxytocin has come up in the world, and several researchers have begun making big claims about it. Now dubbed “the trust hormone,” oxytocin, researchers say, affects everything from our day-to-day life to how we feel about our government.

To understand the role that oxytocin plays in your own life, consider the experience of a small 9-year-old girl named Isabelle. [... who] has Williams syndrome, a rare genetic disorder with a number of symptoms. The children are often physically small and often have developmental delays. But also, kids and adults with Williams love people and are pathologically trusting: They literally have no social fear.

Researchers theorize that this is probably because of a problem with the area in their brain that regulates the manufacture and release of oxytocin. Somehow, the system in which oxytocin operates has been disrupted in a way that makes it essentially biologically impossible for kids like Isabelle to distrust.
[...]
Zak first got interested in trust more than a decade ago after co-authoring a study that looked at trust levels in different nations and their economic stability. The study found that the higher the level of trust, the better the economic status of the nation.

The work got Zak thinking more generally about different ways to manipulate trust. [...] Squirt oxytocin up the nose of a college kid, and he’s 80 percent more likely to distribute his own money to perfect strangers.


Credit:  Oxytocin — The Chemical That Will Make You Trust Everyone