AUSTRALIA 18 March 2012. David Hunter Tow- Director of The Future of Life Research Centre proposes that increasing evidence for the diversity and ubiquity of life in the universe indicates a strong Darwinian selection effect, which in turn indicates that life is an integral part of the Universe, playing a major role in its evolution as a living ecosystem.
Life as an Information Processor
The traditional formulation and scope of physical laws fails to adequately describe complex biological systems. Describing life in terms of the laws of matter and forces is insufficient to capture its complexity or emergent properties. Life can be defined in biological terms by a number of processes and states including adaptation, reproduction, metabolism and evolution. Cell-based components and combinations are linked in multi-dimensional networks to create a living organism, each link defining a critical relationship. The complexity of these networks combined with a dynamic evolving process driven by the need to survive marks a key difference between animate and inanimate phenomena.
However adaptive living systems may be primarily differentiated by their capacity to utilise and process information by storing, monitoring and transforming it. Information is coded, stored and processed in the neural network structures of the brain and nervous system, the DNA, RNA and protein structures of the cell including its microtubule scaffolding, as well as the myriad other chemical, sensory, signalling and metabolic feedback loops that allow life to function within a complex environment.
By transforming information, life evolves towards greater complexity. The more complex life becomes, the better it’s able to learn, adapt and continue its trajectory in the universe.
Ubiquity of Life
With the discovery of a wide spectrum of exoplanets, now approaching 800- including some smaller planets similar to earth, It is now estimated that a substantial proportion of stars have planets, with 160 billion in the milky way alone, as well as potentially trillions of unbound planetary mass bodies and those that orbit brown dwarfs.
The latest simulations also suggest that planets may be common throughout the universe despite the diminishing rate of star formation, with even low mass, dim stars conducive to life on close orbit planets. In the future stars will be richer in the heavier elements critical to life - carbon, oxygen and nitrogen, created by earlier generations of red giant stars, while heavier elements up to uranium will continue to be formed by supernova explosions.
Therefore it can be inferred there is likely to be more life in the future universe, existing on earth-like planets, which will consist almost entirely of heavier elements.
In addition, the discovery of molecular oxygen ions in the atmosphere of Saturn’s moon Dione generated by bombardment from charged particles or photons from the sun or a moon indicates that the ingredients for life may also be abundant on icy space bodies. Subsurface water such as exists on Jupiter’s moon Europa, may also combine molecular oxygen with carbon, to generate life.
Added to this has been the discovery that life can adapt to and flourish in a range of inhospitable environments on earth, from deep ocean hydrothermal vents, to nuclear power plants and beneath the desert. New forms of RNA viruses linked to archaea have also been discovered in the boiling acid pools of the Yellowstone National Park.
Once life gets started it is also very tenacious. Five catastrophic events and many smaller ones have occurred since life’s emergence 3.8 bya, on occasions wiping out up to 90 % of life. But it has always managed to regenerate, often in similar forms.
It is therefore highly probable that life will continue to evolve throughout our universe regardless of catastrophic events on individual planets.
Now combine this cornucopia of potential life with our new understanding of the origins of life and Lee Smolin’s ground breaking work on Cosmological Natural Selection; extending the process of evolution to the creation of life-supporting universes across the vast landscape of different epochs and regions of the Multiverse. The result is a surprising shift towards a much more eco-friendly view of our universe.
Origins of Life
Our understanding of the origins of life and the universe has changed dramatically over the past 50 years, but only recently have the pieces of the jigsaw have come together, allowing us to see the future in a radical way.
There are a number of theories accounting for the origins of life. Did it emerge locally on earth or piggyback in the form of complex organic molecules or microbes on comets and meteorites from other planets within our own solar system or from deeper space?
Regardless, early life on earth did thrive despite the bombardment of sterilizing impacts of meteorites, perhaps by adapting to cooler habitats deep in the crust under the early oceans. Most ancient microbial fossils date from before 3 billion years ago, but the structure of cells implies a long history of even earlier evolution.
The first stage in the evolution of cellular life may have been originally based on an RNA- Ribonucleic Acid template, predating DNA.
In 1980 it was shown that a strand of RNA can act as a template for making another strand of complementary RNA and in 1991 an RNA molecule was synthesised that could make copies of shorter chunks several nucleotides long and join them together. Some RNA molecules can also act as simple enzymes, enabling RNA to both encode information like DNA and perform cutting and joining operations like a protein enzyme.
RNA based life forms could therefore have evolved over millions of years prior to the evolution of the more stable DNA, assembling proteins as well as replicating other RNA molecules for information storage and transmission.
However RNA is more vulnerable to damage than DNA, so at some point in time evolutionary pressure forced proto cells to switch from making RNA copies of an RNA genome to DNA copies of a DNA genome.
But the central mystery of how such a molecule as RNA emerged from early chemistry has remained elusive. The enigma now appears to have been partly solved by Martin A. Nowak, a Professor of Mathematics and Biology and Director of the Program of Evolutionary Dynamics at Harvard University. He has developed a mathematical model of evolutionary dynamics, that simulates the emergence of a pre-life molecular system in the form of efficient self-assembling polymer chains; demonstrating that the molecular building blocks of DNA and RNA provide an evolutionary starting point in pre-life genesis, self-assembling more efficiently over time and accelerating the process of polymerisation.
By the 1960s living organisms had been categorised into two groups- prokaryotes and eukaryotes, with comparative genomics and proteomics strengthening the view that modern eukaryote and prokaryote cells had long followed separate evolutionary trajectories. The simpler prokaryotes, thought to be synonomous with bacteria have traditionally been considered the logical ancestors of the more complex eukaryotes.
But in the late 70s a three-domain hypothesis displaced this assumption. This standard model of genesis suggests that from a common ancestral root evolved three branches representing the domains of life. Genetic sequencing has since shown that life diverged first into archaea and bacteria. Eukaryotes may then have evolved from archaea, subsequently absorbing genes from bacteria twice and acquiring both mitochondria and chloroplast organelles.
But several other anomalies pointed to a more complex starting point. The pattern of evolution appeared not to be as linear or tree like as traditional Darwinian theory may have hypothesised. In fact, lateral or horizontal processes of gene swapping probably occurred many times. Eukaryotes may have evolved from some precursor cell that was the product of a number of gene transfers. The three major domains of life probably therefore arose from a population or pool of primitive ancestral cells that differed in their genes.
By tracing back common proteins from all three it appears plausible that a global organism- the Last Universal ancestor- LUA possibly existed as one superorganism across the oceans of the world as early as 4 billion years ago, evolving In a cooperative rather than a competitive manner. So this latest theory suggests that life emerged a number of times in a variety of ways and provides solid support for the convergent theory of evolution.
A new twist has recently added an extra and crucial dimension to this story- the discovery of a form of life based on inorganic chemistry. Up until now, all life on earth has been assumed to be based on organic biology- carbon in the form of amino acids, nucleotides and sugars etc. But Professor Lee Cronin at Glasgow University has engineered a form of self-replicating, evolving, non-carbon based cell with life-like properties. It has opened the possibility of creating micro organisms from inorganic chemicals- proving that evolution is not just a biological process. This suggests that there may be many alternate sets of non-carbon life forms and that the evolutionary principle may have much more general application than previously understood.
Supporting this argument, Nigel Goldenfeld a physicist and Carl Woese, the biologist who defined a new kingdom of life- the Archaea and developed the RNA World hypothesis, have hypothesized that life is a universal emergent phenomenon that occurs in systems that are far from equilibrium, as Ilya Prigogine originally proposed.
They postulate that evolution is the fundamental physical process that gives rise to biological phenomena, but that it’s full potential has been historically limited by its original biological straightjacket.
One of the strongest and most obvious examples of evolution as a generic process is the genetic algorithm, as previously defined - a method that mimics the Darwinian process of mutation, crossover, selection and replication in abstract mathematical form. A genetic algorithm explores the evolutionary landscape, searching for optimal design solutions, reflected by the DNA processes of life, in the form of local minima.
This indicates that life, as it has evolved on Earth, is just one local solution within a vast landscape of possible options, biological or otherwise. If that's the case, biologists have been studying only a tiny fraction of a much bigger picture.
Creating Life- A New Horizon
Now with increasing confidence, humans have entered the creation business, generating new biological and artificial life forms supporting this hypothesis and expanding the future tableau of life.
Craig Venter and his team were the first scientists to sequence the human genome and have now created the first artificial DNA life-form; a tiny new bacterium or synthetic cell, controlled by human engineered DNA, with its genetic instructions determined by human life.
By creating the first biological life form humans have crossed the rubicon of creation by bypassing natural evolution, opening the floodgates of life’s evolutionary future.
New synthetic life structures can now be created to order by designing novel DNA, facilitating the assembly of genetic building blocks into living systems in the same way that electronic components are combined to manufacture electrical circuits.
Because of this breakthrough it will now be possible to create not only new types of bacteria, but eventually variations in the spectrum of many other living species – plants and animals, including perhaps a new species of humans. In other words, bringing biological life from the super-natural to the human-natural realm of genesis.
Concurrently with developments in synthetic biology, other variations of life in the form of Intelligent software agents and robots have been developed by computer scientists. Such innovations represent life’s evolution in the form of adaptable evolutionary software programs designed to provide autonomous and cooperative problem-solving support to humans through the application of artificial intelligence.
Software agents are a classic example of potential alternative emergent life forms, described as Artificial A-Life or Virtual Life in contrast to 'normal' Biological Life or B-Life.
The principles of A-Life are already being probed and analysed through computational models relating to complexity, self-organisation, diversity, feedback, autocatalysis, cellular automata, network and chaos theory.
Although such organisms might appear goal-directed, they simply do what evolution has shaped them to do. The apparent complexity of their behaviour is largely a reflection of the environment in which they find themselves. This complexity increases dramatically as the environment comes to include information feedback from biological living systems.
Now science’s Pandora’s Box has been opened to release three players in the great game of life- biological, synthetic and virtual. All three will have to learn to co-exist and accommodate with each other, As the biological, technological and social barriers dissolve they will eventually merge into a new entity- Meta-life- a universal autonomous manifestation of intelligence.
Humans are already cooperating in larger and more diverse groups via the Internet to solve more complex scientific, engineering and ethical problems. These require multi-disciplinary and real-time interaction across diverse fields of knowledge to solve the critical challenges facing life today including global warming, environmental pollution, population control, conflict mediation, disease management and the new frontiers of space exploration.
As a result, such virtual communities of researchers and social architects supported by AI technologies are already establishing a presence on the Web representing the prototypes of future symbiotic ecosystems- the early prototypes of universal Meta-life communities.
These developments clearly demonstrate that life is now at the threshold of its most significant transformation. In the near future, the links between AL, SL and BL will be virtually seamless. Powerful AI techniques in the form of neural nets, swarm systems, fuzzy logic and evolutionary algorithms, will merge with the massive pattern analysis capacities of the Web’s computational intelligence; complementing human decision making at a fundamental level and creating a permanent nexus.
Why does Life Exist?
Finally we return to the existential question of not whether life may exist in a kaleidescopic range of novel combinations in the universe, but why it exists at all?
According to Darwinian evolutionary principles, life’s generation and existence on this or any other planet is the result of a selection effect by its environment; not the result of random roulette chance or a deistic manipulation of the laws of nature of this universe.
This is the ‘Third Way’ hypothesis that the Centre has championed over the last ten years. The Universe has not adapted to the highly improbable set of conditions essential to triggering our form of life. Instead, life has adapted to the physical conditions set by the universe- which itself has adapted to the physical and chemical properties of the much larger multiverse.
That is why there is such a perfect and improbable fit for life’s existence on earth and why a certain class of earths, galaxies and universes are likely to be teeming with life similar to our our own. Based on the ubiquity of extreme types of life’s adaptation on this planet, alternate forms are likely to be equally abundant on different earths in different universes.
Part of the answer is connected to the revolutionary idea that cosmologist Lee Smolin introduced over a decade ago, which postulates that each generation of universes has the capacity to spawn child universes, each with slightly altered physical parameters and laws in a mutated form of its parent, eventually creating stars, planets, heavier elements, complex organic molecules and eventually life in some form.
In other words, universes capable of generating life will be also selected by the larger environment of a possible multiverse in the biological Darwinian sense, according to the rules of mutation, selection and replication.
This scenario can then be combined with new information-based evolutionary theories, to offer a third and more verifiable way of explaining life’s existence.
Since its genesis as single-cell organisms on earth nearly 4 billion years ago, life has continued to evolve towards higher levels of genetic and neural complexity; expanding its capacity for more complex information processing, decision-making and knowledge generation. This has allowed it to continue to adapt and survive in a radically changing environment and strongly implies the existence of a powerful Darwinian evolutionary selection process at work.
New information and decision network evolutionary theory also suggests the possibility that life is selected by the environment of the universe as an efficient form of information processor, with the capacity to progress towards higher levels of processing and intelligence, as predicted by stronger versions of the Anthropic principle. Such systems therefore have the requisite complexity and capacity to maximise the amount of information generated over the life of the universe.
At the beginning of the 21st century, the symbiosis of human and computational intelligence has greatly amplified the level of information and knowledge generation and will continue to do so at an exponential rate. This ratcheting process will likely result, in the view of a number of philosophers physicists and cosmologists, in the eventual emergence of a super-intelligent form of life and mind, expanding to become co-existent with the cosmos.
But regardless of such a final outcome, if life has been selected by its cosmic environment as an efficient generator of information, then its capacity to manage entropy and energy resources within its ecosystem -the universe, would be more efficiently and effectively achieved.
This then would be the primary function and role of life in the universe.
As a corollary, life could equally be seen as selecting the living space most appropriate to its continued and enduring evolution. Biological processes might in fact be the means of selecting those laws of physics that best boost life’s own survival. The prerequisite conditions for such opportunistic systems will narrow down the range of possible structures to a small proportion of available configurations, including but not limited to those in which the laws of physics support life as we know it.
A universe teeming with life therefore generates a rich ecosystem, exhibiting emergent system properties- an integral player interacting at every level, as it does on planet earth. It is a dynamic selection outcome of the world we live in and may indeed alter the universe’s capacity as a system to survive, by generating and applying information and knowledge on a grand scale.
The corollary is that the universe is a living entity – interwoven with and exploiting the properties of life.
This is a more realistic way to think of our universe- not as a remote landscape filled with stars, galaxies, black holes, gas and planets with some life forms thrown in by chance; but as a rich ecological system with life at the front and centre of its being.
Philosophical futures have shifted significantly over the past millennium, from the dark despair of the nihilistic ‘heat death’ of the universe to a more optimistic outlook based on an evolutionary ‘becoming’ paradigm.
The problem was that most philosophical models lacked a rigorous scientific basis, a mechanism capable of explaining life's interaction with the cosmos in anything but the most rudimentary meta-physical terms.
Recent forward thinkers such as mathematical physicist Professor Frank Tipler, have gone some way towards providing an alternative to this doomsday view; arguing that in the far future life may exist in a more abstract form, with the capacity to indefinitely delay such an outcome through the generation of an infinite amount of information. Another alternative may be that life will have the capability to create and populate alternate universes.
Tipler also argues that meta-intelligence becomes coexistent with the cosmos, with the rider that the Omega point or ultimate observer may be required to bring the entire universe into existence. In other words, the universe has no determinate form until observed and measured.
An Omega point is therefore postulated as an inevitable outcome of a Multiverse ecosystem capable of sustaining life.
This has enormous philosophical ramifications for us all.