Critique on Vindication of Panspermia, We now have rather interesting Darwinian arguement vis a vis panspermia Options

[ansaazi]

Extracts from arXiv:0908.3943
Critique on Vindication of Panspermia
Pushkar Ganesh Vaidya
Comments: 8 pages, no figures
Journal-ref: Aperion Vol 16. No. 3. pp 463-474 July 2009

[/b]Abstract

In January 2001, air samples were collected from Earth’s stratosphere. From these air samples,
cultures of three microorganisms were obtained. It was reasoned that these microorganisms are of
cometary origin and thereby cometary panspermia stood vindicated. The fact that these
microorganisms had essentially the same characteristics as terrestrial microorganisms was
explained using cometary panspermia. Here, the findings are reinterpreted in the light of niche
ecology and adaptations. It is asserted that the microorganisms captured from the stratosphere
cannot be of cometary origin as they are contrary to the kind of microorganisms one would expect
to find in a cometary niche.

2.1 Characteristics of microorganisms isolated from stratospheric samples

It was reported that both the bacteria captured from the stratosphere were grampositive, non-acid
fast, catalase-positive, and facultatively anaerobic. The bacterial isolates were reported to exhibit
potentially UV-resistant morphologies as the environmental conditions found at 41 km are extreme
in terms of UV exposure, low temperatures and pressures.
No organisms were reported to have been isolated using nutrient-free silica gel medium suggesting
that oligotrophs were absent or, if present, were incapable of growing under the physical chemical
conditions provided by the medium (Wainwright et al.2002).

=============
Note - Henceforth, R will refer to the ‘microorganisms captured from the stratosphere during the
balloon experiment, claimed to be of cometary origin and are the nth generation of the
microorganisms which replicated in comets during the cometesimal formation period, which lasted
for about a million years’.
=============

6. Adaptations & Cometary niche

Species adapt to the ecological niche they occupy. Ecological niche is a term for the position of a
species within an ecosystem, describing both the range of conditions necessary for persistence of
the species, and its ecological role in the ecosystem (Polechová & Storch. 2008).
Extremophiles have adapted to survive in extreme conditions of temperature, acidity, salinity,
pressure, toxin concentration etc. The purpose of this paper is not to list classes of extremophiles
vis-à-vis their adaptations and reiterate how specific adaptations are required for different extreme
ecological niches. (Please refer the works in the suggested reading section). The purpose is simply
to stress the fact that microorganisms can survive in extreme ecological niches provided they
‘adapt’ to those niches.

For instance, a microorganism found in extreme cold environments, must show adaptations as
found in a psychrophile and not a thermophile. To clarify further, a microorganism occupying an
extreme ecological niche must show relevant adaptations although it might be found in
environments where the same adaptations are not essential.
Cometary environment is an extreme environment (refer section 4) and thus is an extreme niche for
any microorganism to occupy. The conditions are so extreme that if a microorganism does not
adapt then it will die.

7. Replication of microorganisms in the Cometary niche

Replication of microorganisms during the cometesimal formation period (refer section 4) which
lasted for about a million years, calls upon evolutionary adaptations in order to survive in the
cometary niche. The major factors which would drive adaptive evolution are given here.

Microgravity

Gravitational acceleration has been constant throughout the ~4B years of biological evolution on
Earth and life forms have evolved to function under a 1-G force. When gravity is altered, biological
changes are observed even when cells are isolated from the whole organism and grown in culture.
It has been shown beyond doubt that microgravity brings about alterations in cellular function,
gene expression and structure (Morey-Holton, E.R. 2003).

Example - To study the effects of space flight on microorganisms, tubes containing Salmonella
were sent as an experimental payload aboard the Space Shuttle Atlantis. Amazingly, compared to
bacteria that remained on Earth for a synchronous control experiment, the space-traveling
Salmonella had changed expression of 167 genes and showed biofilm formation (Wilson et al.
1997).

R do not show any adaptations towards microgravity (refer 2.1).

Cold Temperature

Psychrophiles are extremophiles capable of growth and reproduction at extreme low temperatures.
Lad studies have found them to reproduce at 272 K, just below the freezing point of water (Reid et
al. 2006). Several changes take place inside the cell when it is exposed to low temperature. These
include 1) loss of membrane flexibility, 2) stabilization of secondary structures in nucleic acids, 3)
increase in negative supercoiling of DNA, 4) unfolding or improper folding and methylation of
some proteins and 5) Loss of membrane flexibility affects the membrane-associated functions such
as transport (Phadtare & Inouye. 2008).

Psychrophiles are too small to insulate themselves from these effects of cold and therefore, the only
recourse is to adapt by altering their cellular composition and functions. Adaptations include lipid
cell membranes which are chemically resistant to cold induced stiffening, production of range of
'antifreeze' proteins to keep cellular interior liquid and enzymes protected by cryoprotectants
(Russell. 2008).

Example - Colwellia psychrerythraea 34H has been isolated from Arctic marine sediments. It can
grow even at temperatures as low as 272 K. It produces extracellular polysaccharides and, in
particular, cold-active enzymes with low temperature optima for activity and marked heat
instability (Methe. 2005).

R do not show any adaptations towards low temperatures (refer 2.1).

Low Nutrition

Oligotrophs are organisms that live in low-nutrient habitats. Oligotrophic organisms become small
as a matter of optimizing their surface-to-volume ratio; this is to enhance nutrient uptake. Lownutrient
habitats make the oligotrophs grow slowly which is manifested as a marked decrease in the
production of ribosomes and enzymes (Van Etten. 1999).

Example - S. alaskensis has been isolated from Alaskan waters; an oligotrophic environment. It
shows unique genetic and physiological properties which are fundamentally different from those of
the well studied bacteria such as Escherichia coli (Copeland et al. 2006).
R do not show any adaptations towards oligotrophic conditions (refer 2.1).

Genetic Make-up

Evolution experiments explicitly show how the genomes and phenotypic properties evolve over
generations in microorganism in response to changes in environment (Elena & Lenski. 2003).
Adaptive genetic differences in relation to the ecological niche of a species can be identified by
determining the "selective signature" of a gene; that is, the pattern of fast or slow evolution of that
gene across a group of species, and use that signature to map changes to shifts in an organism's
environment (Shapiro & Alm. 2008).

Example – The genome of Idiomarina loihiensis, a marine bacterium adapted to life near sulfurous
hydrothermal vents, show an integrated mechanism of metabolic adaptation to the constantly
changing deep-sea hydrothermal ecosystem. The genes involved in sugar fermentation, for carbon
and energy underwent significant changes over millions of years to help the bacterium obtain
carbon and energy through amino acid catabolism ;a necessity for life in that ecological niche. The
same genes all completely lost in the psychrophile Colwellia psychrerythraea as sugar metabolism
is not required (Shapiro & Alm. 2008).

R do not show any distinct genetic adaptations necessary for a cometary niche (refer 2.1).

Energy Source

Energy source refers to the pathways used by an organism to produce ATP, which is required for
metabolism. In the absence of light as an energy source a microorganism must explore alternate
pathways; chemotrophy is a pathway by which microorganisms obtain energy by the oxidation of
electron donating molecules in their environments. These molecules can be organic (organotrophs)
or inorganic (lithotrophs) (Pierson. 2001).

Example - Thiobacillus species obtain energy by “burning” compounds such as H2S, S and S2O32-
with oxygen, producing more oxidized forms of sulfur (Harding & Holbert. 2000).
R do not show any pathways necessary to obtain energy in a cometary niche (refer 2.1).

8. Conclusions

The three microorganisms captured during the balloon experiment do not exhibit any distinct
adaptations expected to be seen in microorganisms occupying a cometary niche.
Therefore, the findings of the balloon experiment are re-interpreted whereby it is asserted that these
microorganisms are from a terrestrial source and there exists a hitherto unknown atmospheric
phenomenon to account for their presence.

Consequently, cometary panspermia is not vindicated.

[Phi]

hooray, i can still mate

[Rick]

All that, and there hasn't been enough time for life to have formed light years away and been blown here. No, this is the center of life in the universe.

[Hey Hey]

All that, and there hasn't been enough time for life to have formed light years away and been blown here. No, this is the center of life in the universe.

Rick, do you think that we have the technology to see beyond the end our our nose, yet? Your second very authoritative sentence reminds me of the flat Earthers - cos we ain't been there, there can't be a there! There are stars beyond our star, there are planets beyond our SS's planets, there are moons beyond our SS's planets' moons. So why might there not be independently originated life on some?

And what was that object that passed close to my house the other day?

[Rick]

If you don't know what a passing object is, it must be unidentified.

I'm sure you have some idea about how incredibly vast the cosmos is. Most of it will remain unknown forever. Make the most of it!

If it's not possible to ever know something (like there being life on impossibly distant planets), then it's safe to ignore it. We should expend our neurons on things we can know.

[Hey Hey]

If you don't know what a passing object is, it must be unidentified.

I'm sure you have some idea about how incredibly vast the cosmos is. Most of it will remain unknown forever. Make the most of it!

It it's not possible to ever know something (like there being life on impossibly distant planets), then it's safe to ignore it. We should expend our neurons on things we can know.

Like the ultimate elementary particles (or whatever they are)? And consciousness?

[Rick]

Like the ultimate elementary particles (or whatever they are)? And consciousness?

It's theoretically possible to know the ultimate elementary particles (it may have a bottom somewhere) and it's also possible to understand consciousness some day. It may not be possible to ever communicate with intelligent life elsewhere, assuming it exists. If the saucers land tomorrow, we'll know for sure.

[Hey Hey]

Like the ultimate elementary particles (or whatever they are)? And consciousness?

It's theoretically possible to know the ultimate elementary particles (it may have a bottom somewhere) and it's also possible to understand consciousness some day. It may not be possible to ever communicate with intelligent life elsewhere, assuming it exists. If the saucers land tomorrow, we'll know for sure.

But Rick, it's theoretically possible to predict that life could arise elsewhere in the universe. It's quite basic chemistry and biology really, not as complex as those particle physics equations! Whether or not we'll actually see extraterrestrial life ... well we'll just have to wait and see, but I'm optimistic, especially with so much stuff going on with discovery of extrasolar planets and the like. And we are so primitive with respect to technology at this point. Who know what physical boundaries we might be able to cross in the future, and I'm not just thinking of the next decade, or century, or millennium.
So, I put it to you again, if you are so confident about particles and consciousness, then why not extraterrestrial life?

[Rick]

Because it's possible that life will arise spontaneously on many worlds (and we're just the first one) and it's also possible that it's such an unlikely event that ours is the only world that will give rise to life. The universe is so vast that the number of opportunities may approach infinity, in which case ET life may be theoretically likely, but we can never know it because of the extreme distances involved. Such speculation is akin to counting fairies on pinheads, a complete waste of time.

Better to put our mental efforts into things that can be done, like promoting world peace and prosperity.

[Hey Hey]

Because it's possible that life will arise spontaneously on many worlds (and we're just the first one) and it's also possible that it's such an unlikely event that ours is the only world that will give rise to life. The universe is so vast that the number of opportunities may approach infinity, in which case ET life may be theoretically likely, but we can never know it because of the extreme distances involved. Such speculation is akin to counting fairies on pinheads, a complete waste of time.

Better to put our mental efforts into things that can be done, like promoting world peace and prosperity.

But now we can detect extrasolar planets telescopically we can detect life molecules in the (near) future.

[Rick]

But now we can detect extrasolar planets telescopically we can detect life molecules in the (near) future.

That would be interesting news if it were to occur.

However, carbon dioxide, methane, and ammonia have been known in the solar system planets for many years, and amino acids are present in comets and asteroids (and form spontaneously from sparks passed through simpler molecules), yet it's been pretty conclusively shown that all is sterile out there except for Earth.

[Hey Hey]

But now we can detect extrasolar planets telescopically we can detect life molecules in the (near) future.

That would be interesting news if it were to occur.

However, carbon dioxide, methane, and ammonia have been known in the solar system planets for many years, and amino acids are present in comets and asteroids (and form spontaneously from sparks passed through simpler molecules), yet it's been pretty conclusively shown that all is sterile out there except for Earth.

But soon we will be looking for them on planets and moons around planets. If there are surface or aquatic life forms they will be detectable through their chemistry. Remember, until just 1995 we didn't know there were extrasolar planets. Kepler might crack the nut on life.

[Rick]

I'm not going to hold my breath waiting. LCROSS will impact the moon a week from Fiday (October 9, 2009). Maybe it will find water. That will be interesting. It would be an enabler for solar system colonization. Putting human civilization into space would be a good thing.

[Hey Hey]

Maybe it will find water.

It's already been found: http://www.space.com/businesstechnology/09...moon-water.html

[Rick]

I mean significant quantities, economically feasible to mine. Traces won't do.

[Hey Hey]

I mean significant quantities, economically feasible to mine. Traces won't do.

What do you mean by significant? Economical method to extract yes, but that's just a matter of time to develop the technology. After all, we mine for gold and platinum here on Earth and look at the relatively small amounts (http://money.howstuffworks.com/question213.htm) much of it for simple storage (bullion) or aesthetic usage. If we think the later are worth it, why not water on the moon where the eventual rewards could be enormous?

[Hey Hey]

Just for interest and related to the original topic:

Posted by Paul Collins at 17:31, 02 Dec 2006
B.C. discovery may be older than the sun
Meteorite bolsters theory of how Earth got its evolutionary building blocks
ANNE MCILROY

From Friday's Globe and Mail

Scientists have found tiny bubbles of organic material that may be older than the sun, in a meteorite that landed on a frozen lake in northwestern British Columbia.

NASA researchers say the ancient globules add weight to the theory that space rocks delivered the raw materials required for the evolution of the first life forms on Earth.

"The globules we found in the meteorite aren't alive, but can be an ingredient for it," said Keiko Nakamura-Messenger, who works at the National Aeronautics and Space Administration's Johnson Space Center in Houston.

"We may be one step closer to knowing where our ancestors came from."

She and her colleagues released a detailed chemical analysis of the microscopic globules found within the charcoal-like space rocks that landed near the British Columbia-Yukon border in January, 2000.

The bubbles contain rare types of hydrogen and nitrogen that are not found on Earth. They were formed in intense cold, -260 C, Dr. Nakamura-Messenger said, either in the outer reaches of our nascent solar system or in the giant cloud of cosmic dust and gas that gave birth to our sun and the planets that orbit it.

In today's edition of the journal Science, they say these kinds of globules were likely found in many of the meteorites that bombarded the young Earth. They may have provided the building blocks for life and the perfect protected bubble-like environment for it to form. There were millions of globules in the grape-like piece of rock she studied.

No one is sure how life first evolved on Earth. But the general scientific theory is that compounds that were either already here -- or that arrived on space rocks -- eventually combined and gave rise to a single-celled organism.

Scientists have reported finding these kinds of globules in other meteorites for years, but it was unclear whether they were extraterrestrial material, or the result of human or other earthly contamination.

Dr. Nakamura-Messenger was fulsome in her praise for Jim Brook, the resort operator with a scientific background who knew not to touch the dark chunks of rock he spotted while driving his pickup across the lake. A week earlier, local residents had reported seeing a multicoloured fireball streak to ground, and smelling a foul chemical odour in the air.

She said that if Mr. Brook had touched the space rocks, even a tiny amount of oil from his fingers would have made it more difficult to determine the origins of the ancient bubbles that lay within.

"He did a great, great job and we appreciate that."

He was well rewarded for his efforts.

Earlier this year, he sold the meteorite fragments for $750,000. They will remain in Canada, at the University of Alberta in Edmonton and the Royal Ontario Museum in Toronto.

The initial analysis showed the fragments to be laden with stardust, minerals and organic compounds, said Alan Hildebrand, a meteorite expert at the University of Calgary. It is perhaps the most primitive meteorite ever recovered, a relic from the early moments of our solar system.

The discovery of the organic globules, he said, helps scientists understand more about how a cold, molecular cloud collapses to form a solar system like ours.

He likens the discovery to archeologists finding reeds, wood or grass used by an ancient culture - the kind of material that normally doesn't survive for millions of years.

"These organic globules are some of those things we thought were destroyed, but in fact, they aren't."

Peter Brown, a planetary scientist at the University of Western Ontario, was also on the team that studied the meteorite after it landed. He and his colleagues sent a small sample to NASA, which is what Dr. Nakamura-Messenger and her colleagues used for their research.

But the Americans had access to expensive new equipment that can analyze the chemical composition of tiny structures like the globules, Dr. Brown said.

That analysis shows that the globules are among the oldest material ever found. The bulk of the meteorite is believed to be roughly 4.5 billion years old. The globules could be even more ancient, material that was incorporated into the rock when it formed.

The most pristine chunks are now sitting in a freezer at the University of Alberta, said Chris Herd, assistant professor in the department of Earth and atmospheric sciences.

Many of the pieces look different than the one the NASA scientists examined, he said, and may contain their own secrets.

[Trip like I do]

and yet..... the beat goes on

[Rick]

What do you mean by significant? Economical method to extract yes, but that's just a matter of time to develop the technology. After all, we mine for gold and platinum here on Earth ...

For rocket fuel we will need many tons of water, so it had better be in fairly concentrated form (at least 50% ore) to be feasible to send mining equipment to the moon.

[Hey Hey]

Gravity on Moon less than on Earth. Many tons of water available. Just need mining, extraction and purification method. Stop spending on arms; spend more on expanding human spirit of adventure!

[Rick]

The water mining engineering is rather straightforward. Dig and haul regolith to the roaster. Dump it in. Turn on the electric heaters. Pass the water vapor through a radiator for cooling. Keep it warm enough so it doesn't freeze. Fill the tanks. Put the full water tanks on the electric rail gun. Launch into space.

I think we agree on something!

[Hey Hey]

I think we agree on something!

LOL!

The water mining engineering is rather straightforward. Dig and haul regolith to the roaster. Dump it in. Turn on the electric heaters. Pass the water vapor through a radiator for cooling. Keep it warm enough so it doesn't freeze. Fill the tanks. Put the full water tanks on the electric rail gun. Launch into space.

Sounds like we have to haul a lot of stuff up there to do all this. Maybe we should wait for the ETs to visit us and put our feet up meanwhile. My back aches just thinking about all that mining and I get travel sick anyways.

[Rick]

Living in space will not be easy, but waiting for someone to show us the way is hopeless. It will be an eternal wait. We are number one.

[Hey Hey]

Living in space will not be easy, but waiting for someone to show us the way is hopeless. It will be an eternal wait. We are number one.

You seem to have set your stall in the physics of this universe/time. I prefer to imagine the possibilities of the physics in other universes and times, where our light velocity is surpassed and large distances are no object. There is so much time ahead in which the problems of space travel could probably be solved. If only the human race could survive ...

[Rick]

I prefer to believe in what I know to be possible. If greater things should some day be shown to be possible, so much the better. But for planning our actions here and now, we need to know probable true things.

The alternative is similar to setting an action plan based on winning the lottery. It might happen, but don't count on it.

[Hey Hey]

It might happen, but don't count on it.

He seems pretty confident: http://news.bbc.co.uk/1/hi/programmes/hardtalk/4483221.stm

[Rick]

Physicists love to speculate about things that can't be disproven, don't they?

[maximus242]

lol definitely