Antonio Lazcano’s comments


Add some historical aspects in addition to the philosophical issues.


–Q01: Contingency versus determinism in the origin of life/origin of proteins.

I agree, but only to a point. Moreover, the historical framework may have been essential to define the scientist’s attitude. For instance, Monod position cannot be separated from his strong rejection of the Stalinist attitude of many member of the French Communist Party at the time. Equally significant, while no one can doubt that Monod was a committed materialist, it is also true that he did not pursue his evolutionary thought to the very limits.

And, if you do not agree, which scientific arguments would you offer in favour of one or the other lines of thought?

For instance, against Monod’s arguments, I would raise the issue of the robustness of abiotic organic chemistry, as demonstrated by the same type of compounds synthesized in a wide range of chemical environments, including those in the interstellar medium, cometary nuclei and the parent bodies of meteorites.

–Q02: Emergence and emergent properties: is life an emergent property?

The real issue what do you define as “emergent systems”. In a general way, one would agree of course with this idea, but currently it is clearly part of a trend, mostly found among physicists, that has historical continuity with their efforts to find a general theory for everything, from the formation of galaxies to the vagaries of the stock market…

–Q03: Heterotrophic versus autotrophic scenarios.

I do see strong arguments, namely that the fact that few metabolic intermediates can be synthesized abiotically is not by itself an argument in favour of an autotrophic theory. While one must acknowledge how far we are from demonstrating a heterotrophic origin of life, it is equally true that a reappraisal of the heterotrophic ideas proposed by Oparin is required. The empirical demonstration of an ongoing self-assembled cycle of reactions fixing carbon dioxide would be a strong argument in favor of an autotrophic theory, but this far from being clear.

–Q04: On the origin of catalytic cycles

A few cases of two or three such reactions that can proceed in the absence of enzymes have been shown, but such conversions are also consistent with an heterotrophic theories.

–Q05: On the origin of specific macromolecular sequences

I agree, but recognizing the issue is a not an acknowledgement of its impossibility…

–Q06: About the RNA world

Yes, this is true, but these types of arguments have led to the idea of a (largely undefined) pre-RNA world(s). Hence, it is a complete cul-de-sac.

–Q07: Why this…and not that?

We DO have DNA with uracil (the famous experiments by Arthur Kornberg and mutant viruses) and RNA with thymine, as shown by secondary modifications of tRNA. The issue has been discussed long time by Lazcano et al., 1988, J. Mol. Evol.

–Q08: Proto-cellular world (a)

Early polymolecular systems need not to be seen as early cells. I think there are good arguments for the existence of membranes and the evolutionary significance of enclosure, but one should keep an open mind about the nature of the first living systems and the transition to early cells.

–Q09: Proto-cellular world (b)

See above

–Q10: Life as unity or confederacy

I think it is a valuable approach, and together with Michel Morange I am actually working in this idea.

–Q11: Ecology and individuality

I do not really understand the issues raised…

–Q12: Defining the very origin of life

No, I believe that if we recognize that life is the outcome of an evolutionary process, then a sharp divide needs not to exist. Hence, all the steps mentioned are part of the origin of life.

–Q13: About the anthropic principle (AP)

The anthropic principle is neither anthropic nor a principle –it is a reflection, I think of the very valid philosophical concerns of a group of American physicists. A truly sophisticated discussion can be found in the works of Dominique Lambert, who does have a good training in philosophy.

–Q14: On the entire field of the origin of life

No, I disagree completely. When Miller did his experiment, many where convinced that microbes where germs, that the emergence of life had required billions of years, that planetary systems were rare, that the synthesis of organic compounds was impossible (surprisingly enough, given the 19th century chemical synthesis). The demonstration of the synthesis of many molecules of biochemical significance and the demonstration that protein synthesis emerged in an RNA world (and the concept of the RNA world itself, of course) are evidence of how much more we know…


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: