Cosmic Convergent Evolution (CCE), Part I

Astrobiological Tetrad
“…science is impelled by two main factors,
technological advance and a guiding vision (overview).
A properly balanced relationship between the two
is key to the successful development of a science:
without the proper technological advances, the road ahead is blocked.
W
ithout a guiding vision, there is no road ahead…”
– Carl R. Woese, “A New Biology for a New Century” (2004)


[
It is the Year 2088. Having discovered the design for advanced fusion reactors that can be used for propelling spacecraft and supplying the global energy grid with much-needed power, humanity set out on a more promising course towards a destiny among the stars sometime around the turn of the 21st century. However, many societal and technological challenges remain. The first step towards a sustainable future on our home planet and the eventual goal of interstellar travel is represented by the development of a solar system-wide economy and infrastructure. A number of private and internationally funded consortia are using automated assembly lines of intelligent robots to construct gigantic extraction factories located in the helium-rich atmospheres of the outer gas giant planets. Certain isotopes of this gas are needed to keep the engines of the ongoing interplanetary-industrial revolution going. A fleet of immense and autonomously operated space collectors are fueled by fusion, roaming the asteroid belt to mine abundant metals which are needed as well to allow increasing interplanetary activity. A number of smaller carrier ships guarantee the unhindered travel of an international astronaut corps who check up on humanity’s farthest outposts stationed around Mars, the asteroid belt, Jupiter and Saturn.

Near the “king of the planets,” Jupiter, one of the greatest exploration efforts in humanity’s history is now finally being carried out, financed by the profits generated by mostly peaceful and economically reasonable use of space resources. From one of the main extraction factories orbiting Jupiter, a mighty vessel decouples and sets a path to Europa, the icy pearl of our solar system, which may harbor the incredible miracle of a second genesis of life in our solar system, hidden in the depths of its ocean, covered by a kilometer-thick ice crust. Finally, a mixed manned and robotic mission has been assembled to finally probe this alien habitat for the presence of biological activity. Equipped with landing and habitation capabilities, a giant melting core and even a marvelous human-operated submersible, a team of astronauts and astrobiologists are going to break their way through the formidable ice and descend into the dark waters of Europa to scan the global ocean for signs of alien life. What kind of creatures, if any, is the crew about to encounter below the ice? What awaits humankind, in the icy abyss of this beautiful moon whose mysteries have enticed the curious mind for all of the 21st century? Or even – as one astrobiologist asked back in 2013 – is there a light shining in the eternally sunless waters of Europa after all …? ]

The above is a fictional backdrop for an admittedly optimistic outlook on future space exploration efforts. Strategic planning endeavors concerning the exploration of the outer Solar System’s icy moons, however, should not only bother the minds of a few select visionaries, but should rather inspire and impact the mission design procedures of national and international space agencies – as well as stimulate the imagination of the global populace. A landing scenario on Europa serves fittingly to illustrate the motivation behind the Evo Devo Universe (EDU) research community that was founded by systems theorist John Smart and philosopher Clément Vidal in 2008. Its goal is the fusion of cosmology and biology to facilitate cross-pollination in both fields and eventually achieve a new and comprehensive evolutionary synthesis in which we can begin to understand the evolutionary development of the Universe and, at the same time, gain a cosmological perspective on the possible emergence of biological processes throughout its vast expanses in time and space:

“The underlying paradigm for cosmology is theoretical physics. It has helped us understand much about universal space, time, energy, and matter, but does not presently connect strongly to the emergence of information, computation, life and mind. Fortunately, recent developments in cosmology, theoretical biology, evolutionary developmental biology, information and computation theory, and the complexity sciences are providing complementary yet isolated ways to understand our universe within a broader ‘meta-Darwinian’ framework in which contingent and selectionist or “evolutionary” and convergent, hierarchical, and replicative or “developmental” processes appear to generate complexity at multiple scales. The rigor, relevancy, and limits of an “evolutionary developmental” approach to understanding universal complexity remains an open and understudied domain of scientific and philosophical inquiry.”

Here at EDU we are seeking to envision, elaborate, discuss, test and promote a guiding vision for the emergence of a 21st century universal science of complexity that is able to reconcile thermodynamics with the onset of replication in the prebiotic realm, and to better understand the major transitions in evolution – from protocells to integrated nervous systems in multicellular organisms – as a necessary outcome of a cascading unfoldment, a process of universal complexification, and evolutionary development. Such processes may find their origin in the fundamental physical make-up of our Cosmos, the fabric of the observable Universe, whose threads, the laws of Nature, its DNA, we are beginning to unravel by means of our imagination, rational mind, simulation, and experimentation. Many researchers think of physics as the foundation for chemistry and biology. For the longest part of the past century or two this has been the case indeed. Now, however, we are getting first glimpses of the true vastness of networked biological complexity encapsulated in a single bacterial cell, exponentiated in multicellular life forms, staggering in the workings of our own minds, and, finally, transcended with the imminent advent of autonomously reproducing and evolving technological replicators.

Max Ernst Chemical Nuptials

Our Biocosm viewed from a future macroscopic Multiverse perspective (artist’s impression). Max Ernst, “Chemical Nuptials” (1947 – 1948)

In biology we can uncover deep structures and organizing principles of physical reality such as replication, development, top-down causation, information control and functional closure that defy reduction to purely physico-chemically based bottom-up approaches. Biology is not deducible from physics, we rather have to think of both as intertwined phenomena, and, taking a bold leap, we can reframe our Evo Devo Universe as a Biocosm, a complex adaptive system that is strongly analogous to a living, evolving and developing entity itself:

“The Selfish Biocosm Hypothesis asserts that the anthropic qualities that our universe exhibits can be explained as incidental consequence of a cosmological replication cycle in which a cosmologically extended biosphere supplies two of the essential elements of self-replication, as identified by mathematician and computer pioneer John von Neumann. Further, the hypothesis asserts that the emergence of life and intelligence are key epigenetic thresholds in the cosmological replication cycle, strongly favored by the physical laws and constants of inanimate nature. Under the hypothesis, those laws and constants function precisely as the functional counterpart to DNA: They furnish the recipe by which the evolving cosmos acquires the capacity to generate life and ever more capable intelligence. The hypothesis reconceives the process of earthly evolution as a miniscule subroutine in an inconceivably vast process of cosmic ontogenesis. A falsifiable implication of the hypothesis is that the emergence of increasingly intelligent life is a robust phenomenon, strongly favored by the natural processes of biological evolution and emergence.” – James N. Gardner, The Intelligent Universe (2007). 

Reading Gardner’s Biocosm brought me in contact with EDU ideas. Gardner is one of 90 scholars presently in the EDU research and discussion community. Conveniently, his book was able to provide a theoretical superstructure in which to pursue my own studies into an alternate origin of life on Jupiter’s moon Europa. My own humble contribution to our nascent field, the concept of Cosmic Convergent Evolution (CCE), will be elaborated in more detail in part II of this introductory series. CCE is, as a matter of fact, a corollary to the Biocosm theorem.

Through the ages speculative minds, often in mythological and sometimes in more naturalistic terms, have contemplated the idea of our own Universe being an organismic system. In the following I will argue that this idea is more than a mere theorem or speculation and, operating at the very forefront of scientific enquiry, is actually presenting us with falsifiable hypotheses that can be put to the test within this century. Let me try to explain.

At the moment I am concluding my masters thesis at the European Molecular Biology Laboratory (Heidelberg, Germany) in the field of developmental neurobiology. I am studying early phases in nervous system evolution, and more precisely, the synaptogenesis of cholinergic neurons. Since completing my bachelor thesis, however, I have been working continuously in the area of astrobiology as well, pursuing extensive private and academic studies concerning the phenomenon of convergent evolution. The beginning of my quest to better grasp the emergence of biological complexity in Earth’s evolutionary history and beyond was posed by an apparently simple question: If there is life on Jupiter’s moon Europa – how does it originate, evolve, and develop and what would extant forms and function look like? Contemplating this issue opens a perplexingly intricate set of nested problems pertaining to the nature of life itself. Pondering the generalities of evolving and developing biological organization eventually led me, on a path that many of our community’s scholars have also independently taken prior to the affiliation with EDU, to the hypothesis of universal (thus cosmologically shared but independently and repeatedly emerging) organismal complexity. EDU scholar Carlos Mariscal calls this the search for ‘Universal Biology’ and it is of course one foundation of the emerging field of astrobiology.

Within this field, which is concerned with the origin, distribution and future of life in the Universe – there already exists a consensus that Europa, the icy moon of Jupiter which is slightly smaller than our own, is the prime candidate for hosting putative alien ecosystems, most likely microbial but also potentially encompassing multicellular organisms. Saturn’s tiny but geologically active satellite Enceladus is also a candidate, as we shall see.

What makes these moons such tantalizing places to look for life beyond Earth?

Astrobiological Tetrad

The most promising astrobiological tetrad of our own Solar System: Europa (bottom left) and Enceladus (top right) with their assumedly highest degree of biological complexity, multicellular comb-jelly like organisms (above Europa), and microbial archaea-like methanogens (below Enceladus)

We have learned a great deal about the possibility of life on Europa by exploring remote areas of our own planet, areas that most researchers have taken for granted to be “too extreme” for any kind of known biology to work. Environmental conditions at the terrestrial abyssal seafloor, for example, are hostile to life in many ways: low temperature, high pressure, the absence of sunlight and very limited energy sources. These factors originally convinced many in the scientific community that it was essentially a waste of time to look for life in these locales. Ecosystems, it was said, depend on the energy flux of the sun at a fundamental level and all members of the food chain eventually derive the power to keep their metabolism running by consuming compounds whose chemical energy was provided by photosynthetic processes at some point.

But astonishingly, in the late 1970s, entire communities of microbial and multicellular organisms where found thriving in a symbiotic relationship around hydrothermal vents at the dark bottom of the oceans across the globe. Along underwater continental fault lines, fresh mantle crust is exposed to the overlying water column, providing a source of one of life’s primary requirements, long-term stable energy flux. Through open cracks near these spreading centers, sea water percolates down into the ocean floor, gets heated, and rises up again due to its increased buoyancy. During this process, the chemical composition of the water gets altered by the intense heating and interactions with the surrounding rock. Trace metals, CO2, H2, CH4 and other compounds are thus enriched in the hydrothermal fluids. As the super-heated liquids are vented out into the colder ambient ocean again, dissolved minerals and metals precipitate and form characteristic chimney structures. These mineral rich environments are colonized by chemoautotrophic microorganisms, extremophiles from the ancient domains of eubacteria and archaea. These organisms are adapted to intense heat and can perform the synthesis of organic molecules by harnessing the chemical energy released by the reactions occurring in the vicinity of the hydrothermal vents. The microbes are at the base of these lightless ecosystems can even allow complex multicellular life to prosper, due to intricate emergent symbiotic relationships. After the discovery of such ecosystems, which are solely based on chemical rather than solar energy, it appeared imaginable to scientists that analogous oases of life could originate and evolve in similar planetary environments where life cannot depend on the ceaseless flux of solar radiation. But where in our solar system can we envision habitats like the terrestrial deep-sea and its underlying crust?

Lost City

Alkaline hydrothermal vents of the Lost City field, possible geochemical cradles for the origin of life on Earth

Europa and Enceladus are great candidates for such geothermally-based life, according to planetary evolution modeling of their internal structures. In addition, recent data obtained from the Cassini space mission is very suggestive of the presence of ongoing hydrothermal activity on Enceladus. Apparently, nano-silica particles (2 – 8 nm radius) were detected by the probe’s Cosmic Dust Analyzer (CDA) instrument. Further investigations on Earth including hydrothermal simulation experiments indicate that these particles were potentially formed in an alkaline (~ ph 11), high-temperature (> 90° C) aqueous solution and were transported quickly upwards through the ice cracks (ranging from months to several years). Eventually the particles were then ejected via the south pole’s plumes. These findings synergize on multiple levels with ongoing theoretical and experimental work regarding the origin of life on Earth in rendering likely the emergence of biology beyond our home planet.

Terrestrial hydrothermal vents do not only represent thriving oases of extant life but the latest research on the emergence of life is proposing that these geochemical cradles (more precisely warm alkaline vents in contrast to extremely hot black smokers) might actually have hatched the earliest biological replicators: autocatalytic supramolecular complexes of various kinds engaging in communal non-Darwinian evolution within their inorganic micro-compartments formed by precipitation of vented iron-sulfur metals. Amazingly, such a temperate, alkaline geochemical environment might just have been detected by the previously mentioned Cassini mission inside the planetary womb of Enceladus.

Non-darwinian processes of evolution in this context refer to a phase in which variation was rather conferred via horizontal gene transfer and not by vertically transmitted genetic information of fully integrated cellular entities. In fact, classical Darwinian concepts involving gradualism and competing selfish replicons often fall short on a theoretical level to explain sudden and systemic increases of higher-level biological complexity on multiple bio-organizational scales (meaning beyond early evolutionary stages as well). Explaining pre-cellular evolution and multicellular bio-complexity in purely Darwinian terms is like describing the quantum world with Newtonian physics. It is easy to see that “Universal Newtonism” is not able to unify modern-day physics; why should “Universal Darwinism” be able to do so when we consider the ever-increasing non-linear hyperspace of biological complexity?

Personally, I never fully understood how Darwinism is purported to “integrate” all of the existing biological sciences. Among biologists it is widely acknowledged that The Origin of Species didn’t even satisfactorily explain its main subject, namely the process of speciation. As science progresses, we have to let go of much cherished models (i.e. the Neo-Darwinian Synthesis) that do not suffice anymore to explain the phenomena we are theorizing and observing. Or to use a biological analogy: a kind of endosymbiosis takes place, where an advanced cell takes up a more limited-complexity unit, and eventually integrates it into its own cellular context where it will serve an important but subordinate function (given it is still viable within the new systemic whole; degeneration and disintegration is always an option too). This is simply how science works. Hard-core Darwinists (again, why are there no “Newtonists” around anymore?) shouldn’t fear some evil machinations of the creationists they so much love to vilify. They should rather watch out for the impact of overwhelming amounts of new biological data as well as novel theoretical concepts, on their paradigms. In my opinion, orthodox understandings of evolutionary theory simply fail in explaining the observation of emerging higher-order systemic complexity through every major evolutionary transition. Any other approach apart from letting go of previous world-views will become dogma and ultimately earn its deserved spot in the dustbin of history. Let us turn again to the words of the eminent Carl R. Woese, in whose memory NASA’s “Institute for Universal Biology” was founded:

In the last several decades we have seen the molecular reductionist reformulation of biology grind to a halt, its vision of the future spent, leaving us with only a gigantic whirring bio-technology machine. Biology today is little more than an engineering discipline. Thus, biology is at the point where it must choose between two paths: either continue on its current track, in which case it will become mired in the present, in application, or break free of reductionist hegemony, reintegrate itself, and press forward once more as a fundamental science. The latter course means an emphasis on holistic, “nonlinear,” emergent biology — with understanding evolution and the nature of biological form as the primary, defining goals of a new biology.” – Carl Woese, “A New Biology for a New Century” MMBR (2004)

Central Dogma

Decisive steps in “horizontal” prebiotic and protocellular evolution leading toward vertical inheritance marked by the “Darwinian threshold”; in this scenario informational architectures are more important than the constituting biochemistries. (Image Source: NASA Workshop report titled “Alternative Biochemistries of Life – Empirical Approaches” by Goodwin et al.).

How does all of this relate to Jupiter’s moon? Europa is often called the “ocean moon” for a very good reason. Since the onset of outer Solar System exploration with the Pioneer and Voyager spacecraft in 1972, over forty years ago, planetary scientists have been intrigued with the smallest among the Galilean satellites (named after their discoverer Galileo Galilei) along with Io, Ganymede and Callisto. The first images sent in the late 1970s, around the same time when hydrothermal vent fields were discovered in the terrestrial oceans, revealed fascinating surface features: long single and double ridges stripping almost around the moon in its entirety, rough texture in some areas, and the high reflectivity of the surface made scientists wonder if Europa’s ice crust could possibly rest upon a vast global ocean. Modelling of the satellite’s planetary history and its continual gravitational interactions with the other Galilean moons soon provided further evidence for a potential liquid water ocean under the ice. Immense tidal energies resulting from Jupiter and Io and Ganymede could work vigorously within Europa’s interior, keeping enormous amounts of ice in liquid phase.

Around the turn of the century, the Galileo spacecraft had already orbited the Jupiter system for a couple of years, when amazing new data was relayed back to Earth. High-resolution imagery of novel and previously observed surface features reminded some researchers of massive disintegrated ice shelves floating around and freezing back together as seen in Antarctica. Measurements of induced magnetic fields were established as the most compelling argument for the existence of a planet-wide liquid water layer around 100 km in depth. Calculations showed that if the models held true, Europa would possess twice or triple the amount of water in all oceans on Earth combined. More data from the Galileo probe helped to work out its planetary profile.

Today most researchers believe that Jupiter’s moon is a differentiated body with an iron core, a silicate mantle and an overlying water ocean with a depth of 80 – 100 km covered by a sealing shell of ice. On the surface chemical compounds were detected which formed by the reaction of water and carbon dioxide ices with particles, accelerated by Jupiter’s magnetic field, showering down on the exterior of the moon. In this process, oxidized substances are produced which likely get transported down in to the ocean and dissolve into molecular oxygen and hydrogen. High oxygen levels in the upper ocean layers would drastically increase the chances for complex, multicellular life. Europa’s differentiation and apparently active geology is also suggesting the presence of hydrothermal systems on the seafloor which could act as the previously mentioned geochemical cradles for the emergence of biological activity. If life on Europa had once originated in the ancient past, the increasing complexity of evolving and developing organisms would surely have found a way to deal with the pressing energy constraints prevailing inside the dark and cold ocean. Life itself is the most potent process known to transform a dead planet into a thriving and diverse biosphere. This might have occurred hidden from our eye within Europa’s ocean.

Europa Ice Shell

Thin-shell vs. thick-shell model of Europa’s ice shell; in the first model the liquid ocean has a depth between 80 – 100 km. Any future in situ exploration of the aquatic habitat depends on a relatively thin ice layer. Future space missions are going to resolve this controversy (most planetary scientists today favor the thin-shell model). Image taken from Figueredo et al. (2003)

After planetary scientists have done their work in identifying a given world in our solar system as potentially habitable, it is the turn of astrobiologists to investigate the biological problems faced by life in the course of its envisioned evolution on an alien moon. How did it get started in the first place? Are there only microbes or even multicellular forms? Is it using DNA, RNA and proteins like on Earth? Will there be life forms emitting biologically produced light as widely observed in terrestrial oceans, especially the deep sea? Do general laws govern the process of increasing biological complexity?

Some theoretical biologists argue that the evolution of life is largely determined by random events and environmental conditions; others argue that there must be a “deep structure” to life, universal mechanisms shaping organisms according to the same principles across the whole Universe. The exploration of Europa and the discovery of extraterrestrial life there would help us answer this profound question: is biological evolution restricted to Earth or is it a cosmic phenomenon? On our home planet we are relatively certain that “life as we know it” requires liquid water, biogenic elements and a stable energy source. All of these criteria are, to our best knowledge, met inside the subsurface ocean of Europa. Are these physical parameters enough to reliably predict the existence of an alien biosphere? Here is where it gets tricky again.

In the next post we will delve deeply into the systemic and informational architecture of life, and begin to explore how a second genesis of life on the moons of the outer Solar System could be potentially predicted from EDU’s growing theoretical corpus that is, again, centered on one core idea: an evolving and developing Universe…

Author Information: Claudio L. Flores Martinez is one of seven EDU research community directors. Born in Hamburg, Germany, he earned his bachelor’s degree in biosciences at the University of Heidelberg. After finishing his master’s thesis in developmental biology at EMBL Heidelberg he is planning on pursuing a PhD at the intersection between complexity sciences and astrobiology. Email: claudio.flores.martinez@embl.de

References

Figueredo, P.H., Greeley, R., Neuer, S., Irwin, L., Schulze-Makuch, D. (2003).“ Locating potential biosignatures on Europa from surface geology observations”. Astrobiology 3:851–861.

Flores Martinez, C. L. (2014). “SETI in the light of cosmic convergent evolution.” Acta Astronautica 104(1): 341-349.

Flores Martinez, C. L. (2015). “Convergent evolution and the search for biosignatures within the solar system and beyond.” Acta Astronautica 116:394-402.

Gardner, J. N. (2003). Biocosm: The New Scientific Theory of Evolution: Intelligent Life is the Architect of the Universe, Inner Ocean.

Gardner, J. N. (2007). Intelligent Universe : AI, ET, and the Emerging Mind of the Cosmos. New Page.

Goldenfeld, N. and C. Woese (2007). “Biology’s next revolution.” Nature 445(7126): 369-369.

Goodwin, J.T.; Walker, S.I.; Amin, S.; Armbrust, G.; Burrows, C.J.; Lynn, D.G. (2014) “Alternative Chemistries of Life: Empirical Approaches (PDF)”, NASA & NSF-Sponsored Workshop Report.

Hsu, H.-W., et al. (2015). “Ongoing hydrothermal activities within Enceladus.” Nature 519(7542): 207-210.

Last, C. (2015). “Big Historical Foundations for Deep Future Speculations: Cosmic Evolution, Atechnogenesis, and Technocultural Civilization.” Foundations of Science: 1-86.

Morris, S. C. (2003). “The navigation of biological hyperspace.” International Journal of Astrobiology 2(02):149-152.

Russell, M. J., et al. (2014). “The drive to life on wet and icy worlds.” Astrobiology 14(4): 308-343.

Smart, J. M. (2009). “Evo Devo Universe? A Framework for Speculations on Cosmic Culture (PDF).” In: M. L. L. and Steven J. Dick. Cosmos and Culture: Cultural Evolution in a Cosmic Context (PDF), NASA Press, pp. 201-295.

Vidal, C. (2014). The Beginning and the End: The Meaning of Life in a Cosmological Perspective (PDF). Springer.

Woese, C. R. (2004). “A new biology for a new century.” Microbiol Mol Biol Rev 68(2): 173-186.

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