Dr. Bruce Damer presents a talk linking the new "Hot Spring Hypothesis" for the origin of life to the search for life in our Solar System and beyond on exoplanets. His host, the renowned physicist and activist Dr. Pervez Hoodbhoy, hosted this talk at the Physics department auditorium at Quaid-i-Azam University in Islamabad , Pakistan. Dr. Bruce “inflamed the minds” of Pakistani students and professors alike as he took them on a rapid romp through life’s possible origins on Earth to the search for evidence for life on Mars in 2020, icy Enceladus in the next decade and onward to the likelihood of life on exoplanets. Dr. Bruce Damer and Prof. Pervez Hoodbhoy (presenters), Elixir Technologies Pakistan (recording and support). [presented 17 November 2017]. Find a podcast with audio, video and additional information about this presentation at: http://www.levityzone.org/lz-episode-059-origins-science-comes-pakistan/

1. The Hot Spring Hypothesis for the Origin of Life:
implications for science and the search for life
on Mars, Enceladus and Exoplanets
QAU, Islamabad, Pakistan
10 November, 2017
Bruce Damer, University of California, Santa Cruz
David Deamer, Martin Van Kranendonk, Malcolm Walter, Tara Djokic

2. The Science of the Origin of Life:
Charles Darwin’s intuition-1871
"But if (and oh what a big if) we could conceive in
some warm little pond with all sorts of ammonia
and phosphoric salts, light, heat, electricity
etcetera present, that a protein compound was
chemically formed, ready to undergo still more
complex changes [..] " ~Charles Darwin, in a letter
to Joseph Hooker (1871)

3. The Science of Origin of Life:
1920s-50s Haldane-Oparin “soups”
Alexander Oparin's and J. B. S. Haldane's hypothesis:
putative conditions on the primitive Earth favored
chemical reactions that synthesized more complex
organic compounds from simpler inorganic precursors.
1953-Miller-Urey spark chamber synthesis
Synthesis of amino acids launched experimental phase of
origin of life research.
1977 Discovery-deep sea hydrothermal vents
Suggested as a location for an origin of life by Corliss,
Russell, Martin, Lane et al. Polymerization and
encapsulation not yet demonstrated.
-> Chemistry community now returning its focus to
land-based pools.

4. A search for life’s origins
A “Field Trip to the Archaean” (July 2015)

5. Living stromatolites of Shark Bay

6. Onwards to the Pilbara

7. Stromatolites 2.6-3.5 Billion Years Old

8. Stromatolites 2.6-3.5 Billion Years Old

9. The earliest evidence of life on land discovered in 3.5 Ga preserved
strata of fresh water hot springs in Western Australia* is suggestive of
an earlier fresh water origin of life.
Hot Spring Geyserite with Microbial Fabrics, 3.5Ga
Qz
B
- Terracettes with palisade fabric (silicified microbial filaments)
- Oxygen or hydrothermal gases trapped in EPS as bubbles (?)

10. Observed continuity in the rock record from the earliest evidence for
life in the fresh water stromatolites of the Dresser Formation to the
living marine stromatolites at Shark Bay.
Hot Spring Geyserite with Microbial Fabrics, 3.5Ga
Dresser-geyserite with
stromatolites, fresh water hot
spring @ 3.5Ga
Dresser-subsurface vein
stromatolites @ 3.5Ga
Shark Bay-living
marine stromatolites
Tumbiana-lakeshore
stromatolites @ 2.7Ga

11. The “Goldilocks chemistry” (Joyce) for an origin of life is
found in inland hydrothermal “warm little fluctuating pools”.
ExtremeOptimal
time

12. collect
concentrate
cycle
adapt stress
distribute
“Pools of fitness” and downhill distribution provides
resources and evolutionary gradients for early life
Early life on Earth had hundreds of millions of years to establish robust
adaptations such as photoautotrophy and protein synthesis.

13. Field testing the hypothesis: “Hot Little Pool” Kamchatka Russia
Pools collect & concentrate molecular inventories: meteoritic (IDPs)
and hydrothermal sources for nucleobases, amino acids, fatty acids,
key elements (C, Zn, B, P, and N), minerals for prebiotic chemistry.
Access to 3 energy sources:
heat activation, dehydration and
sunlight.
Regular wet-dry cycling in
presence of membranes to drive
polymerization reactions.
Membraneous structures form
in hydrothermal field conditions
from 14 carbon fatty acid,
glycerol, Phosphate, @ pH 3.
Feedstock from meteoritic
compounds concentrating on land.

14. Hydration-dehydration cycling – David Deamer 1980s
CO2 atmosphere, 85 C, pH 3
Discovery: prebiotic, non-enzymatic polymerization
-> RNA-like polymers are produced
through a few cycles of 4-24 hours.
Hydration-dehydration cycles with
nucleobases (A, U) in presence of lipid
H2O rehydrationCO2 dehydration
Hydration-dehydration of
amino acids ->peptides
(Hud, Cronin, ELSI). -> Gels: 40-150mer polymer of A+U.
Nanopore sequencing identifies polymers.

15. 2 nucleobases (A,U) +
amphiphile (Phosphatidylcholine)
@ pH 3
Polymerization of RNA-like polymers has now been
observed in exposure to hydrothermal field conditions
Field testing the hypothesis: fumarole polymerization
Bumpass Hell, Mount Lassen Volcanic Park, California

16. Downward flow, upward adaptation gradient still visible today
The role of silica gels in microbial filaments and sinter endoliths
New Insights from Yellowstone fieldwork July 2017
Research conducted under
Yellowstone Research Permit
YELL-2017-SCI-7020

17. Lipid: decanoic acid+
decanoyl monoglyceride
Monomers: dAMP+TMP
Fluorescent stain: DAPI
Cyclic polymerization of
nucleotides works both in
presence of clay or
dissolved silica.
When dried lipid layers are exposed to rehydration, large numbers of
vesicles “bud off” some containing random polymers. Each provides
an experiment in a natural process of combinatorial selection for
function (stabilization, pores, metabolism).
Encapsulation of synthesized polymers

18. A metaphor from computer science…

20. Mechanism for an Origin of Life in a Cycling Hot Spring Pool
Laboratory demonstration of synthesis of polymers and encapsulation
within protocells through three coupled phases
The rate of polymer synthesis exceeds the rate of hydrolysis so a kinetic trap is created
permitting continuous re-synthesis and combinatorial selection of functional polymers
driving molecular evolution to a Woese/Fox progenote and then to a living system.
Dehydration synthesis of
polymers-RNA and
peptides-
between
lipid
lamellae
Encapsulation of
polymers in protocells
Delivery of surviving
protocells to interactive
gel phase
Testing of
protocells for
stability
Protocells dry, fuse
back into lamellae,
transfer polymers

21. A Hot Spring
Origin of Life
…ultimately gives rise to LUCA
and marine stromatolites
2. Accumulation
1. Synthesis
3. Concentration
5. Distribution
6. Adaption
7. Colonization
4.Cycling

22. Scientific American, August 2017 cover story
Hot Spring Model: Public Interest
Qz
B

23. And now on to Mars: the Search for Life in
the Inner Solar System

24. History: hand count that sent Spirit to Gusev
JPL final MER landing site selection meeting-Jan 2003

25. Today: 3rd Mars2020 landing site selection
meeting-Feb 2017

26. How the Hot Spring Hypothesis for an Origin of Life can
Guide Mars Exploration (Mars2020 Rover)
In a search for evidence of ancient life in the earliest (Noachian)
history of Mars, it would be useful to apply a chemical and
geological framework for an origin of life on any terrestrial world.
Recent discoveries providing a body of evidence: Pilbara 3.5Ga
terrestrial hot springs are a primary early driver for life on Earth;
new laboratory discoveries suggest a viable chemical pathway.
Applying these principles we can posit when, where, and how
long life needs to start and robustly establish on Earth or Mars.
Early life on Mars would be in a race against a rapidly retracting
habitable environment. Therefore if hot springs are a likely place
where life can start, they are also a likely place to search for the
last and best preserved accessible evidence for past life.

27. Columbia Hills Landing Ellipse
Proposer identifie
regions of interest
J.W. Rice

28. Inner Basin and Home Plate
J.W. Rice

29. Columbia Hills Region:
Geologic Processes and Diversity
Processes
Impact
Plains Volcanism
Hydro-Volcanism
Fluvial
Lacustrine
Aeolian
Diversity
Silica
Carbonates
Sulfates
Basalts
J.W. Rice

30. Opaline Silica Deposits (up to 91 wt % SiO2) located
near Home Plate. These silica-rich deposits (light-
toned soils & bedrock) are interpreted to have
formed in hot springs. Terrestrial hydrothermal
environments support thriving microbial
ecosystems.
Silica precipitation well known to
promote biosignature preservation.

31. Spirit “split rocks” through wheel scuffing action
under the weight of the vehicle

32. Innocent
Bystander
1 cm
MI image: Coated grains (Ruff
et al., 2011)
El Tatio coated breccia (same scale)
-> The need to break rocks
Nodular Silica Textures

33. Breaking Rock in the Pilbara
3.5Ga stromatolite

34. Reasons to Return to the Columbia Hills
Key advantage and unique aspect of this landing site is that we
already know exactly where we need to go and have
already found significant astrobiologic and geologic
samples to be collected, complements of Spirit.
J.W. Rice

35. Outer Solar System: Life on Enceladus?

36. Where on Earth? Two sites -- vents and fields
“Black smokers” Alkaline vents Hydrothermal field
Salty sea water Fresh water

37. Methanogenic microorganisms could exist in the
Enceladus ocean, but they would require nutrients
and a source of chemical energy such as hydrogen.
There is no light, and no photosynthesis.
Methanocaldococcus

38. Hydrothermal vents: Physics, chemistry and biology
Abundant microbial life exists in the absence of light energy
Salty sea water: ca. 600 mM NaCl, 54 mM MgCl2, 10 mM CaCl2
Potential sources of energy: Redox potentials, pH gradients, thermal
gradients
Hydrogen in solution provides reducing power
Abundant trace metals
Potential limitations
Dilution of potential reactants and products into surrounding sea water
No demonstrated concentrating capacity in actual vent minerals
No demonstrated containers in vent minerals
Thermodynamic barrier to condensation reactions
Salt concentration and divalent cations inhibit membrane assembly

39. Hydrothermal fields: Physics, chemistry and biology
Abundant thermophilic microbial life
Fresh water from precipitation
Acidic pH from sulfur compounds, carbon dioxide
Cycles of dehydration and rehydration
Reactants extremely concentrated by evaporation
Potential sources of energy: Concentration effects, light energy
Condensation reactions are thermodynamically feasible
Self-assembly of amphiphilic membranes is possible
Polymerization has been demonstrated
Potential limitations
What sources of organic compounds provide reactants?
Clay minerals may adsorb potential reactants
Reactions that could lead to metabolism have not been demonstrated
No obvious source of reducing power
Minimal trace metals

40. If life can begin in hydrothermal vent conditions, then life
could emerge in the Enceladus ocean and may still exist.
If the origin of life requires fluctuating hydrothermal fields,
Enceladus and Europa may be habitable but lifeless.
Early Mars had abundant volcanism and hydrothermal fields.
These conditions are conducive for the origin of life, so life
could have emerged on Mars just as it did on Earth and may
still exist as halophilic extremophiles in Martian brines.
Summary I – Enceladus and Mars

41. Summary II –
Enceladus Predictions
What might be detected in samples of
Enceladus plumes?
(silicon nanopore instrument design at UCSC)
If the ocean is sterile, it is likely to be a dilute solution of the
kinds of small molecules present in carbonaceous
chondrites: monocarboxylic acids, amino acids, polycyclic
aromatic hydrocarbons, alkanes, trace amounts of purines.
If microbial life originated and still exists, the biosignatures
will include fragments of polymers, specialized species of
hydrocarbons and enantiomeric excesses of chiral
molecules.

42. And now beyond to Exoplanets:
Earthlike Planets, Hot & Close

43. Exoplanets:
TRAPPIST-1 System, 7 Earthlike planets, red dwarf
Exoplanets in a habitable zone

44. Artist’s Conceptions of Exoplanet Life
Life requires polymers with encapsulation & combinatorial
selection -> aqueous carbon (not exotic) chemistry

45. Collaborators and Supporters
UC Santa Cruz
Australian Centre for Astrobiology
Univ. New South Wales
McMaster University
Center for Chemical Evolution,
Georgia Tech.
Cronin Lab, University of Glasgow
Acknowledgements
University of Paris
University of Washington
Harry Lonsdale Research Award
NASA
DigitalSpace Research
Thanks to QAU, Prof. Pervez Hoodbhoy and the
Lahore Astronomical Society for inviting and
supporting this talk
Biota Institute: origins.biota.org
Contact: Bruce Damer bdamer@ucsc.edu