Comment on “Fundamental molecules of life are pigments which arose and co-evolved as a response to the thermodynamic imperative of dissipating the prevailing solar spectrum” by K. Michaelian and A. Simeonov (2015)

Björn, Lars Olof

doi:https://doi.org/10.5194/bg-19-1013-2022

Articles | Volume 19, issue 3

https://doi.org/10.5194/bg-19-1013-2022

© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/bg-19-1013-2022

© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 19, issue 3

Peer-reviewed comment

|

16 Feb 2022

Peer-reviewed comment |

| 16 Feb 2022

Comment on “Fundamental molecules of life are pigments which arose and co-evolved as a response to the thermodynamic imperative of dissipating the prevailing solar spectrum” by K. Michaelian and A. Simeonov (2015)

Lars Olof Björn

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Final revised paper (published on 16 Feb 2022)
Preprint (discussion started on 29 Jun 2021)
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Interactive discussion

Status: closed

RC1:
'Comment on bg-2021-135', William Martin, 29 Jun 2021

The critique is good and should be published. K. Michaelian and A. Simeonov (2015) call everything that absorbs photons a pigment, which is incorrect, as Björn points out. The worst flaw in the K. Michaelian and A. Simeonov (2015) paper is however, that if life arose at submarine hydrothermal vents, as some have been saying for 30 years and as some eidence suggests (Weiss et al. Nature Microbiol 2016; Preiner et al. Nature Ecol Evol 2020), then no light at all was required at life's origin, it was just chemical energy. But even if light was required, the reasoning in K. Michaelian and A. Simeonov (2015) is flawed and, worse, teleogical to the extreme (life arose to serve a purpose).

Citation: https://doi.org/10.5194/bg-2021-135-RC1
- CC1:
  'Reply on RC1', Karo Michaelian, 03 Jul 2021
  
  Michaelian and Simeonov (2015a) do not “call everything that absorbs photons a pigment”. (See point 4 of the comment by Michaelian and Simeonov (2015b) on our original article for validation of the use of the word “pigment” in our paper.) We suggest that those organic molecules now known as the fundamental molecules of life (i.e. those in the 3 domains of life) that strongly absorb light within the 210-285 nm (UVC) region and have a conical intersection to rapidly dissipate the electronic excitation energy into heat (Michaelian2011;2017;2021) were originally (at the origin of life) organic pigments which were dissipatively structured from simpler and more common precursor molecules under this UVC light to perform the thermodynamic function of dissipating this light into heat.
  There are numerous and conflicting theories for the origin of life. There is no inherent reason to believe that the hydrothermal vent theory is the correct theory. Our theory, of course, does not have to facilitate, or even be consistent with, any other particular theory, no matter how appealing the other theory may seem. Our theory only has to be consistent with known chemical and physical principles and laws and with the probable initial conditions, i.e. known facts about possible physical environments at the origin of life. It is not scientifically sound to label a theory “flawed” simply because it is not consistent with a favored theory!
  The whole system, dissipative structure (pigment or organism) plus driving potential (the photon potential), is under the dictates of the Second Law of Thermodynamics, as is every macroscopic biotic process (including evolution), as well as is every abiotic process. There is nothing personal or particular about it, this law is intrinsic to all processes. The Second Law for the biological processes states that the entropy of the organism(s) plus that of its environment must increase. It is the Second Law that gives function-existence closure to the dissipative structure and its inseparable driving potential. It is completely unnecessary to bring philosophical concepts like teleology into the discussion. However, for those who still think in these terms rather than in terms of physical law, the telos of pigments or life (or any dissipative structure) would be to dissipate the solar photon potential (or any generalized thermodynamic potential) and it is precisely this dissipation on which the structure depends for its very existence. The teleology (if you must) is thus intrinsic (Jonas, 1966; Mossio and Bich, 2014).
  Karo Michaelian and Aleksandar Simeonov
  References
  Jonas, H. (1966). The Phenomenon of Life. Towards a Philosophical Biology. New York: Harper and Row.
  Michaelian, K., Simeonov, A., Fundamental molecules of life are pigments which arose and co-evolved as a response to the thermodynamic imperative of dissipating the prevailing solar spectrum, Biogeosciences,; 12(16), 4913-4937 (2015a). https://bg.copernicus.org/articles/12/4913/2015/
  Michaelian, K. and A. Simeonov, A., Interactive comment on “Fundamental molecules of life are pigments which arose and evolved to dissipate the solar spectrum”. Biogeosciences Discuss., 12, C1904–C1917 (2015b), www.biogeosciences-discuss.net/12/C1904/2015.
  Michaelian, K., Thermodynamic dissipation theory for the origin of life, Earth Syst. Dynam., 2, 37-51 (2011) doi:10.5194/esd-2-37-2011. https://esd.copernicus.org/articles/2/37/2011/
  Michaelian, K., Microscopic dissipative structuring and proliferation at the origin of life, Heliyon, 3 (10) (2017), e00424, ISSN 2405-8440, https://doi.org/10.1016/j.heliyon.2017.e00424; (http://www.sciencedirect.com/science/article/pii/S2405844017319060)
  Michaelian, K., The Dissipative Photochemical Origin of Life: UVC Abiogenesis of Adenine, Entropy, 23 (2), 217 (2021); https://doi.org/10.3390/e23020217, https://www.mdpi.com/1099-4300/23/2/217
  Mossio, M. and Bich, L. What makes biological organisation teleological?. Synthese, Springer Verlag (Germany), 2014, http://link.springer.com/article/10.1007/s11229-014-0594-z.
  
  Citation: https://doi.org/10.5194/bg-2021-135-CC1
  - RC3: 'Reply on CC1', William Martin, 20 Jul 2021
    
    The critical comment by Björn should be published. His paper is carefully worded, polite and well argued. The response by Michaelian is unsatisfactory in my view, as is the 2015 paper that initiated Björn's comment. The teleological components in the original are not erased by Michaelian's glib fomulations. The belief that solar radiation was required for life's origin is just that. Life is so short. There are papers explaining why chlorophyll based photosynthesis likely arose at hydrothermal vents, in line with the far red absorbance of dark green chlorosome containing bactreria that live there. No albedo at the bottom of the ocean. The critical comment by Björn should be published.
    
    Citation: https://doi.org/10.5194/bg-2021-135-RC3
    
    AC6: 'Reply on RC3', Lars Olof Björn, 20 Aug 2021
    
    No comment.
    
    Citation: https://doi.org/10.5194/bg-2021-135-AC6
  - AC2: 'Reply on CC1', Lars Olof Björn, 20 Aug 2021
    
    No comment
    
    Citation: https://doi.org/10.5194/bg-2021-135-AC2
- AC5: 'Reply on RC1', Lars Olof Björn, 20 Aug 2021
  
  No comment.
  
  Citation: https://doi.org/10.5194/bg-2021-135-AC5
RC2:
'Comment on bg-2021-135', Axel Kleidon, 15 Jul 2021

This comment criticises the paper by Michaelian and Simeonov (M&S), which was published in 2015 in Biogeosciences. The commentary is motivated by the claims in M&S that "The driving force behind the origin and evolution of life has been the thermodynamic imperative of increasing the entropy production of the biosphere through increasing the global solar photon dissipation rate". While I sympathise with this critical attitude towards this claim and believe that M&S could well be a subject to a scientific debate, I not think that the comment in its current form provides a substantial contribution. I therefore recommend rejection in its present form.

Specifically, the comment questions the statement that “Living systems reduce the albedo of Earth” and elaborates whether this statement is correct. The manuscript uses the example of the Moon and compares it to the Earth, and provides some anecdotal evidence where life is not darker than its surroundings. Yet, this comparison is flawed, because what we would need to compare is an Earth without life to an Earth with life, not with another planetary body (Simulations of such conditions have been made, e.g., Kleidon et al. (2000) "A green planet versus a desert world", Clim Change, 44: 471-493.). Furthermore, it is textbook knowledge that the surface albedo of forests is in most cases darker than bare ground, even though there may be some isolated exceptions.

Hence, I find the arguments brought forward quite shallow and not strong enough to challenge M&S. As an example of a much more specific criticism that in my view reflects a substantial contribution to a scientific debate, I may refer to the paper of Volk and Pauluis (2010), " It is not the entropy you produce, rather, how you produce it", Phil Trans B, 365: 1317-1322.

Citation: https://doi.org/10.5194/bg-2021-135-RC2
- CC2: 'Reply on RC2', Karo Michaelian, 18 Jul 2021
  
  We agree with Axel Kleidon that the Comment by Lars Olof Björn is “not strong enough to challenge” our original postulate. We also agree with Kleidon that the comparison of the albedo of the Earth and the moon is not relevant, not only because they are very different astronomical bodies, but also because albedo is a poor proxy for entropy production. A simple calculation including not only the reflected light (albedo), but also the emitted red-shifted spectrum, shows, in fact, that the Earth’s interaction with its solar environment produces significantly more entropy per unit surface area than does the moon, even though the Earth has larger albedo.
  We also agree with Axel Kleidon that our proposition (that the fundamental molecules of life were dissipatively structured (“self-organized”) pigments from simpler precursor molecules under UVC light as a result of the thermodynamic imperative to dissipate the impressed UV photon potential into heat) should be subjected to rigorous scientific debate. This is important in order to establish elements of plausibility for our thermodynamic dissipation theory for the origin of life (Michaelian 2009;2011;2016;2017;2021; Michaelian and Simeonov 2015) and to establish how entropy production fits into the scheme of biological evolution and Earth System evolution. Finally, we believe that it is important to present these ideas to biologists who traditionally are not trained in non-equilibrium thermodynamics but nonetheless have an important perspective and we therefore welcome and appreciate the challenges of Björn and Martin.
  The article that Kleidon references by Volk and Pauluis (2010) which criticizes the maximum entropy production (MEP) hypothesis is not relevant to our paper since we neither reference, employ, nor endorse the MEP hypothesis. Our paper is instead based on Classical Irreversible Thermodynamic theory developed by Lars Onsager and Ilya Prigogine and coworkers. The work of Prigogine and coworkers showed that far from equilibrium there does not exist a potential whose optimization could describe the evolution of a system. For non-linear systems far from equilibrium, beyond a bifurcation point in a given parameter, multiple stationary states become available, each with a distinct entropy production rate and distinct local stability. The system can evolve over these states through fluctuations near the bifurcation points. The entropy production of the system could either increase or decrease in the new stationary state. However, when states with autocatalytic routes to dissipation exist, they provide large attraction basins in generalized phase space and a small fluctuation near a bifurcation would be more likely to lead the system towards these autocatalytic greater entropy producing stationary states (Michaelian, 2021).
  Evolution of systems far from equilibrium, therefore, involves both deterministic and stochastic elements. The path taken by the system can only be determined probabilistically by doing a local calculation of the stability in the neighborhood of the stationary states (Glansdorff and Prigogine, 1971), which is related to the sizes and shapes of the respective attraction basins. The probabilistic tendency of autocatalytic systems (having the possibility of autocatalytic routes to dissipation) to move towards increasing their entropy production over time is therefore scientifically sound within the range of applicability of Classical Irreversible Thermodynamic theory in the non-linear regime, but, a general potential, such as MEP, for describing the evolution of arbitrary systems far from equilibrium has not been found.
  Karo Michaelian and Aleksandar Simeonov
  References
  Glansdorff, P. and Prigogine, I., Thermodynamic Theory of Structure, Stability and Fluctuations, Wiley-Interscience, New York, (1971).
  Michaelian, K., Thermodynamic Origin of Life, Cornell rXiv arXiv:0907.0042 [physics.gen-ph] (2009) https://arxiv.org/abs/0907.0042
  Michaelian, K., Thermodynamic dissipation theory for the origin of life, Earth Syst. Dynam., 2, 37-51 (2011) doi:10.5194/esd-2-37-2011. https://esd.copernicus.org/articles/2/37/2011/
  Michaelian, K., Simeonov, A., Fundamental molecules of life are pigments which arose and co-evolved as a response to the thermodynamic imperative of dissipating the prevailing solar spectrum, Biogeosciences,; 12(16), 4913-4937 (2015). https://bg.copernicus.org/articles/12/4913/2015/
  Michaelian, K., Thermodynamic Dissipation Theory of the Origin and Evolution of Life: Salient characteristics of RNA and DNA and other fundamental molecules suggest an origin of life driven by UV-C light, Printed by CreateSpace, Mexico City, (2016). ISBN: 9781541317482, DOI: 10.13140/RG.2.1.3222.7443
  Michaelian, K., Microscopic dissipative structuring and proliferation at the origin of life, Heliyon, 3 (10) (2017), e00424, ISSN 2405-8440, https://doi.org/10.1016/j.heliyon.2017.e00424; http://www.sciencedirect.com/science/article/pii/S2405844017319060
  Michaelian, K., The Dissipative Photochemical Origin of Life: UVC Abiogenesis of Adenine, Entropy, 23 (2), 217 (2021); https://doi.org/10.3390/e23020217, https://www.mdpi.com/1099-4300/23/2/217
  Volk and Pauluis, It is not the entropy you produce, rather, how you produce it, Phil Trans B, 365: 1317-1322 (2010), https://royalsocietypublishing.org/doi/abs/10.1098/rstb.2010.0019
  
  Citation: https://doi.org/10.5194/bg-2021-135-CC2
- RC4:
  'Reply on RC2', William Martin, 20 Jul 2021
  
  I disagree. The critical comment by Björn should be published. On entropy, I can recommend a paper by Battley, a biologist who measured entropy changes in biological systems for decades: L. D. Hansen, R. S. Criddle, E. H. Battley, Biological calorimetry and the thermodynamics of the origination and evolution of life. Pure Appl. Chem. 81, 1843–1855 (2009). There we can read that the measured changes in entropy in biological systems are always zero or close to zero and that because cells are organized in a spontaneous process, no energy input is required to maintain the structure or organization of cells. If one is to get into entorpy in living systems, one has to look at the literature where it is quantified, not asumptions about what it should be. Overall the best aspect of this discourse was the paper by Björn, which is apparently not going to see the light of day. Oh well. With physicists and geoexperts around, who needs biologists when it comes to life? Next time I go to the doctor I'll ask for an equation. Battley's discussion of entropy and information is a classic, I highly recommend it (search the text for Gedankenexperiment). I would have thought that the journal (and Michaelian) would be happy that someone mentions the 2015 paper in 2021.
  
  Citation: https://doi.org/10.5194/bg-2021-135-RC4
  - RC5: 'Reply on RC4', Axel Kleidon, 20 Jul 2021
    
    There are two issues involved here:
    1. Is the claim by Michaelian & Simeonov (2015) valid or useful? Here I side with the skeptical attitude of the author of the commentary and with William Martin. I do not believe MS2015, and doubt that it has much value. So there would be quite a bit that can be criticisized, but this criticism in its own needs to be well justified and substantiated.
    2. Is the commentary by Björn well justified and substantiated? As I expressed in my review, it is not. For a commentary, I would expect something stronger and better argued, and I gave an example of how such a commentary could look like in the review. In the case of MS2015, I think that such a more substantial commentary would be easy to do.
    Because of (2.), I recommend rejection of this comment.
    
    Citation: https://doi.org/10.5194/bg-2021-135-RC5
    
    AC8: 'Reply on RC5', Lars Olof Björn, 20 Aug 2021
    
    See reply to RC2.
    
    Citation: https://doi.org/10.5194/bg-2021-135-AC8
  - CC3: 'Reply on RC4', Karo Michaelian, 23 Jul 2021
    
    We welcome and appreciate scientifically sound and sufficiently elaborated challenges to our proposition concerning photon dissipation and the origin and evolution of life. However, emotional comments based on “feelings” without elaboration, such as, “K. Michaelian and A. Simeonov (2015) is flawed…”, “The response by Michaelian is unsatisfactory in my view…” , “I do not believe MS2015, and doubt that it has much value…”, do not contribute to the scientific discussion.
    The teleological concern that Martin continues to bring up is a red herring. We have already made clear that the concept of a telos is completely unnecessary once life and evolution are accepted to be under the dictates of the 2^nd law of thermodynamics. Martin’s vigorous defense of hydrothermal vent scenarios of the origin of life is also misplaced since it is by no means a generally accepted scenario, not the least because very few fundamental molecules have ever been produced under ideal laboratory simulations of hydrothermal vents. Indeed, Stanley Miller emphatically argued until the end of his life that hydrothermal vents were regions of molecular destruction, not molecular creation. Martin’s latest reference to Battley et al.’s (Pure Appl. Chem., Vol. 81, No. 10, pp. 1843–1855, 2009) analysis of the entropy of a random collection of molecules compared to the same collection within a living being but “in a state of suspended animation” is pointless exercise since life is a process, not a particular static arrangement of molecules in suspended animation. The reduction in entropy due to the formation of the molecules, and that due to the dynamics of the processes of life, must also be included for a meaningful comparison of entropies (Battley et al. should have been aware that Schrödinger certainly understood this). However, we don’t have to be concerned with that here (other than to perhaps inform Battley et al. of their oversight), what we are interested in is the entropy production, not the entropy. A particular static arrangement of biomolecules has zero entropy production; it is a dead organism, or a dead ecosystem. Living systems are very much concerned with positive entropy production and, as we suggest, have been generally increasing the entropy production of Earth in its solar environment since the origin of life.
    We would not oppose the publication of Björn’s Comment as long as, in the interest of a fair and open scientific debate, Björn and defenders do not oppose the publication of our Reply.
    Karo Michaelian and Aleksandar Simeonov
    
    Citation: https://doi.org/10.5194/bg-2021-135-CC3
    
    AC1: 'Reply on CC3', Lars Olof Björn, 23 Jul 2021
    
    I do not oppose the publication of reply CC3 by Karo Michaelian and Aleksandar Simeonov.
    Lars Olof Björn
    
    Citation: https://doi.org/10.5194/bg-2021-135-AC1
    
    RC6: 'Reply on CC3', William Martin, 23 Jul 2021
    
    Michaelian's (erroneous) comments are about me as a person rather than about the paper or the science. That is abuse, which I hereby report.
    
    Citation: https://doi.org/10.5194/bg-2021-135-RC6
    
    AC9: 'Reply on RC6', Lars Olof Björn, 20 Aug 2021
    
    No comment.
    
    Citation: https://doi.org/10.5194/bg-2021-135-AC9
  - AC7: 'Reply on RC4', Lars Olof Björn, 20 Aug 2021
    
    No comment.
    
    Citation: https://doi.org/10.5194/bg-2021-135-AC7
- AC3: 'Reply on RC2', Lars Olof Björn, 20 Aug 2021
  
  Please see attached "reply to RC2.pdf"
  
  Citation: https://doi.org/10.5194/bg-2021-135-AC3
CC4: 'Comment on bg-2021-135', Karo Michaelian, 09 Aug 2021

We have submitted a formal Reply (bg-2021-199, see supplementary .pdf file attatched to this comment) to Lars Olof Björn’s Comment on our article “Fundamental molecules of life are pigments which arose and co-evolved as a response to the thermodynamic imperative of dissipating the prevailing solar spectrum” by Karo Michaelian and Aleksandar Simeonov. In summary, Björn makes the erroneous assumption that albedo (reflection) is the only important factor related to photon dissipation (entropy production) occurring in the light-pigment interaction in living systems. He ignores the other contributions to entropy production due to the photon interaction which were listed in our article; 1) the shift towards the infrared of the emitted spectrum, 2) the diffuse emission and reflection of light into a greater outgoing solid angle, 3) the coupling of photon-induced evapotranspiration in the pigmented leaf to further photon dissipating processes such as the water cycle, which further allows dissipating biopigments to flourish over all of Earth’s surface. His assumption is therefore incorrect and his analysis does not provide legitimate reason for doubting our assertion that the fundamental molecules of life arose as pigments as a response to the thermodynamic imperative of dissipating the prevailing solar spectrum. Please see our attached .pdf file for details.

In the interest of furthering a deeper, open, and fair disscusion of this important theme within the community, we believe that both our Reply and Björn’s Comment should be published together in Biogeosciences. Lars Björn has indicated his agreement with this arrangement in his comment in this list.
Karo Michaelian and Aleksandar Simeonov

Citation: https://doi.org/10.5194/bg-2021-135-CC4

Peer review completion

AR: Author's response | RR: Referee report | ED: Editor decision

ED: Reconsider after major revisions (26 Sep 2021) by Carolin Löscher

AR by Lars Olof Björn on behalf of the Authors (20 Oct 2021) Author's response Author's tracked changes

ED: Referee Nomination & Report Request started (03 Nov 2021) by Carolin Löscher

RR by Anonymous Referee #3 (19 Nov 2021)

Suggestions for revision or reasons for rejection

The hypotheses described by K. Michaelian and A. Simeonov are an interesting one and worthy of debate and should not be disregarded entirely. I think Björn makes some valid critical points, however, I feel that the arguments are somewhat weak and require further justification. I believe the ms is worthy of publication if the arguments were strengthened. Many of the arguments included in the ms involve modern systems. As Michaelian and Simeonov state, ‘These fundamental molecules today, having lost their direct dissipating utility, have taken on new roles’. It would be nice to include a more in-depth discussion and argumentation involving early life and evolution of life and the biosphere.

I believe the following changes would strengthen the ms whilst still showing a balanced argument. The aim of which would hopefully spark a pleasant scientific discussion.

L28-30. Making comparisons to Mars and the moon take away from the narrative. Let the focus purely be on Earth and the evolution of living systems on Earth.

Section. 2 Vegetation compared to bare ground.

I think the changing albedo of glaciers/ice sheets due to ice algae should be touched upon in this section.

L36. I am not sure what point you are trying to make with this lead sentence.
L37. You disregard the importance of UV radiation but it could be of importance when thinking about primitive PAH pigments, as well as UV-absorbing pigments in marine algae.
L38. Do not start a sentence with ‘And’. Also, fix the grammatical errors within this sentence.
L44. Please clarify. ‘ground albedo increases with the proportion of cyanobacteria cover (compared to cover by cyanobacteria, moss, and lichen)…’ Do you mean a mix of cyanobacteria, moss, and lichen?
L47. Fix, ‘De opposite effect’.

Section 3 The temporal aspect
L72. Legend. ‘ Fix. The variation of cyanobacteria coverage was partly natural, partly caused by experimental treatment during several years (watering, heating, or both)’
L76. Fix, ‘We cannot back from our responsibility….’

Section 4 The aquatic environment.
There are a few extra important points which could be included in this section. These include, the impacts of sea-foam formed from marine algal surfactants and marine aerosols (DMS) and cloud formation.

L80-81. ‘since we do not have to deal with gases’. Yes, but we still have to deal with dissolved gases.
L89-90. I would include the sargassum paper by Bach et al. here.
L101. A gap is needed. ‘(2020) and…’.

Bach, L.T., Tamsitt, V., Gower, J. et al. Testing the climate intervention potential of ocean afforestation using the Great Atlantic Sargassum Belt. Nat Commun 12, 2556 (2021). https://doi.org/10.1038/s41467-021-22837-2

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ED: Reconsider after major revisions (29 Nov 2021) by Carolin Löscher

AR by Lars Olof Björn on behalf of the Authors (07 Dec 2021) Author's response Author's tracked changes Manuscript

ED: Referee Nomination & Report Request started (14 Dec 2021) by Carolin Löscher

RR by Anonymous Referee #3 (05 Jan 2022)

ED: Publish subject to technical corrections (11 Jan 2022) by Carolin Löscher

Short summary

The origin and evolution of life do not contradict the laws of thermodynamics, but we have no proof that it is an inevitable consequence of these laws. We do not know if the first life arose under illumination or in darkness in the deep ocean or in the Earth's crust. We have no proof that it arose due to a thermodynamic imperative of dissipating the prevailing solar spectrum, as there are other ways for entropy increase in solar radiation. The biosphere may instead delay entropy production.