zankaon

March 3, 2017

Earliest life forms?

Filed under: Letters from Ionia — Tags: , — zankaon @ 3:27 pm

Recent reports suggest microbial life in ancient hydrothermal vents in rocks ~3.77- 4.28 Byrs ago – Nuvvuagittuq Supracrustal Belt (NSB). However is there the possibility of a later date infusion of fluid rock material?

For example, for Gunflint trail formation and vicinity, one has ancient shield rocks, but with later volcanic intrusion rocks, associates with the Mid-continental rift ~1 Byrs ago.

Just one billion years is an enormous geological time span, wherein almost any thing can occur. Animalia (such as sponges) might have arisen approximately 1 billion years ago; an almost inconceivable span of biological evolutionary time. 

So nature has had an enormous amount of time to try all possibilities. That is, a temporal series can be transformed into an ensemble of all spatial realized states. But is this sufficient? There also must be preservation, stability, allowing for an accumulation of mass, in regards to structural or functional elements; such as stabi!ity of amide bond for between amino acids?

For example, adsorption to a surface, and/or a dryer environment. Thus co-evolution of stabilizing preservation conditions, factors etc. would seem to be of equal importance.


http://www.bbc.com/news/science-environment-39117523

https://en.m.wikipedia.org/wiki/Midcontinent_Rift_System#/editor

November 7, 2012

Amide linkage chemical bond and origin of life

Filed under: Letters from Ionia — Tags: , , — zankaon @ 8:21 pm

Amino acids have amide linkage HN-C=O. Are other linkages possible, and exist, such as for plants, and for microbial world? Has nature had the opportunity to try other combinations, and based on energetics and kinetics, selected (in part?) such amide linkage as most robust to perturbation i.e. stable? Chemical reactions occur over ~10^-9/sec – 10^-15/s; so ideally perhaps 10^9-15 reactions per sec, which dwarfs 4 x 10^9 years.

Again is stability (as for a dryer surface?) a co-evolving selection factor essential in any origin of life scenario, whether here or for another world – a dryer Martian scenario? Thus would initial geological nitrogen fixation and subsequent amide linkage seem general features typical for life anywhere? Is an amide bond more stable than most alternative choices? Hence a chemical bond example of importance, for such selection for stability concept, for early evolution of life here, and throughout the universe? Nature has had plenty of time to explore the space of all chemical possibilities on this planet. So wouldn’t such sparse sampling suffice for exploring a general universal chemistry approach – giving rise to life?

Pattabtraman V.R., Bode J.W., Rethinking Amide Bond Synthesis, Nature Vol 480 p. 471, Dec. 22/29, 2011, and references therein.

June 29, 2012

Hematite, photosynthesis, silicates – connections? Martian rock ice? No sedimentary layers? olivine on Mars

Might hematite be the only marker of eroded ancient sedimentary seabed sites? Has billions of years of erosive wind action resulted in an unconformity? That is, might significant sedimentary layers not be found, nor present, anywhere on Mars, secondary to erosive wind effect over billions of  years?  Or can sedementa:y rock be formed from below, due to sulfate fusion of layers, giving a sedimentary app:arance? Consistent with the prediction of no hematite at deeper bored levels? Might Gale crater be a counter example to such lack of sedimentary layer scenario, or contrarily, an aeolian effect?

Could one integrate an area for abundance of hematite, and thus oxygen content? Thus inferring the amount of oxygenation for given seas’ volume, or just per hematite distribution? The latter would supposedly denote only areas, within geographical seas, for photosynthesis, since no significant aeolian re-distribution of hematite. Then would this set limits on amount of photosynthesis that occurred? Also would any oxygenation of martian atmosphere be very limited, in light of very slow oxygenation of our atmosphere?

Would widespread prevalence of unweatherized olivine on Mars, without secondary mineralization, be consistent with most of surface water disappearing very early; hence likewise for surface life? Thus a constrain on life’s duration on Mars; a fast start and finish?

Or might a thick atmosphere (protection from UV radiation), and intermittent dew and/or frost be sufficient for origin of life on a dryer surface? Would the latter dryer surface be consistent with importance of stability in the preservation of any newly formed molecular combinations, in a transient aqueous environment?

Also Tharsis plateau volcanic complex is of a shield volcanic nature, and not explosive. Hence consistent with no viscous silicates (silicon oxides), and hence consistent with no significant past oxygenated atmospheric weathering effect for Mars.

For any so-called martian rock ice to form sub-surface, still a significant vapor pressure and thus significant atmosphere (1/10 bar?) must have been present.

Perhaps micro frozen ‘fossils’ might be found in such rock ice. Not multi-cellular, since not enough time for multi-cellularity to evolve. For example, Animalia and metazoa evolved much later on earth. One could drill into sub-surface smooth (not a glass from amorphous rapid cooling?) martian rock ice, and compare amperage etc. to a similar fine bore drilling for earth ice; the difference being proportional to density. Also infrared spectroscopy for such probe? Thus might such martian rock ice formation be considered as a gradual ongoing solid physical phase change?

Would a gradual increase in hydrogen bond strength for between water molecules then account for lack of sublimation of such ice, both sub-surface and on the surface, in part at mid latitude, and also at North Pole especially? That is, why is there snow at all at North Pole, especially in summer? ~6 millibars should result in sublimation of snow at the pole. Would the retention of such not so thick snow be consistent with increased (covalent ?) strenght of hydrogen bond for between water molecules, not only sub-surface, but also for surface water ice/snow, any where on Mars? Might one utilize orbital infrared spectroscopy of residual polar cap snow, to look for such increased hydrogen bond strength for between water molecules?

So billion year old effect of increasing bond strength and stiffness (i.e. bending, stretching) for hydrogen bond (i.e. for between water molecules) – giving almost covalent bond strength? There is wide variation in hydrogen bond strength.

Infrared spectroscopy measures vibration modes of water, and all modes of vibration are infrared active. Then compare such infrared signature of bond strength to earth ice. Also such martian rock ice would look like rock, and seem hard like rock, but much lighter; consistent with lower density than rock. Also a different melting temperature from earth ice, and becomes mottled from exposure to ultraviolet light. Likewise for any Martian meteorites on earth ; so slicing, and looking for any pitting after uv exposure, with comparative controls, would seem to confirm it’s origin. TMM

olivine on Mars

Martian sub-surface ice, mid latitude

Infrared_spectroscopy

Hydrogen_bond

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