ExomatrixTV
27th September 2012, 15:09
EXCERPT FROM: http://goo.gl/sncPj
6. Scientific implications :spy:
If we find evidence for a second genesis of life, we will certainly learn from the comparative study of the biochemistry, organismal biology and ecology of the alien life.
Even if an alternative life is based on carbon and water, it may have a different biochemical system. The number of distinct macromolecules that can be constructed from carbon is combinatorial, and thus very large. It may well be that life with a different origin and different history uses a different set of carbon-based molecules for its genetic and structural functions, rather than the DNA/RNA and proteins used for these functions by life as we know it. Having a second example of biochemistry would allow us to compare and contrast two biochemical systems both capable of sustaining life. From this comparative study, we might begin to understand which features of Earth biochemistry are universal and which features are particular to the historical developments on Earth.
In addition to comparisons at the biochemical level, it would be interesting to compare the cell structure and organization. Even more broadly, if we can observe or re-create entire ecosystems based on alien life, the potential for comparison is greatly expanded. In the widest sense, an alien biosphere composed of alien organisms using a different pattern of biomolecules gives the greatest scope for scientific return by comparison.
In addition to the biochemical, organismal and ecological levels, comparing life as we know it to a second genesis may help to address questions related to understanding the tree of life itself. One example question in this category is the fact that, of the two domains of life that are entirely microbial, only one (the bacteria) cause disease. The other domain (the archaea) are found in our intestines (about 1% of the human intestinal microbes are archaea) and in many ways are more similar to eukaryotes than bacteria. The archaea are also more closely related on the tree of life to eukaryotes than are bacteria. Yet, there is no known disease or infection caused by archaeal micro-organisms. A complete understanding of this may require an overall understanding of the tree of life that will most easily come with having another type of life to compare with.
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7. Societal implications :peep:
The discovery of alien life, if alive or revivable, will pose fundamentally new questions in environmental ethics. Ethically and scientifically, we would do well to strive to support any alien life discovered as part of an overall commitment to enhancing the richness and diversity of life in the Universe.
The current field of astrobiology differs from other disciplines in space science in one fundamental way: astrobiology explicitly includes the question of what is the future of life in the Universe? This should motivate us to consider the long-term goal for human choices and actions with respect to life in the Universe. Human choices, while they should be informed by science, depend on ethical, economic and broad societal considerations. McKay [[URL="http://rsta.royalsocietypublishing.org/content/369/1936/594.full?sid=c3394c53-7f29-4bad-afd4-1ad01060b7c5#ref-50"]50 (http://rsta.royalsocietypublishing.org/content/369/1936/594.full?sid=c3394c53-7f29-4bad-afd4-1ad01060b7c5#sec-8)] has suggested that the long-term goal for astrobiology should be to enhance the richness and diversity of life in the Universe and that our choices and actions should reflect this goal.
McKay [50 (http://rsta.royalsocietypublishing.org/content/369/1936/594.full?sid=c3394c53-7f29-4bad-afd4-1ad01060b7c5#ref-50)] suggests that, while life is not the only source of value in the natural world, it is unique in that it is something of value that can be preserved, but it can also be spread without limit. If life has value then humans can create value and spread value as they spread life. In this sense, a focus on enhancing life connects to the deeply seated motivation for humans to be active creators, or co-creators, helping to shape and guide the existing creation and contributing to its diversity [50 (http://rsta.royalsocietypublishing.org/content/369/1936/594.full?sid=c3394c53-7f29-4bad-afd4-1ad01060b7c5#ref-50)].
While human action can contribute to life, it can also cause damage if unchecked. A relevant and current example is the biological contamination associated with exploration of potentially biological worlds like Mars. The search for life on Mars poses a logical dilemma: how to search for life without contaminating Mars with life from Earth. Such contamination poses two dangers. First, the search for life on Mars may give positive results because of life carried from Earth. Secondly, alien life forms native on Mars may be endangered by competition with transplanted Earth life.
Mars is interesting because it may have had life in the past and because it may be a place for life in the future. However, we are uncertain of the current biological state of Mars. There are at least three possibilities: (i) there is life on Mars that is distinctly different from life on Earth—a second genesis; (ii) there is life on Mars that is genetically related to life on Earth; and (iii) there is no life on Mars. Each of these possibilities implies distinctly different scenarios for how we can best explore Mars. Until we know which of these possibilities is correct, we must explore Mars in a way that keeps our options open with respect to future life.
One solution to this dilemma is that we must explore Mars in a way that is biologically reversible. Exploration is biologically reversible if it is possible and practicable to remove all life forms carried to Mars by that exploration. Because of the high ultraviolet and oxidizing conditions on the surface of Mars, the robotic and human exploration of the planet can be done in a way that is biologically reversible. We must be able to undo (‘ctrl Z’) our contamination of Mars if we discover a second genesis of life [51 (http://rsta.royalsocietypublishing.org/content/369/1936/594.full?sid=c3394c53-7f29-4bad-afd4-1ad01060b7c5#ref-51)–53 (http://rsta.royalsocietypublishing.org/content/369/1936/594.full?sid=c3394c53-7f29-4bad-afd4-1ad01060b7c5#ref-53)].
It has been proposed that re-creating a biosphere on Mars (e.g. [54 (http://rsta.royalsocietypublishing.org/content/369/1936/594.full?sid=c3394c53-7f29-4bad-afd4-1ad01060b7c5#ref-54)]) based on indigenous life, or, lacking indigenous life, based on Earth life, would contribute to expanding the richness and diversity of life in the Universe [52 (http://rsta.royalsocietypublishing.org/content/369/1936/594.full?sid=c3394c53-7f29-4bad-afd4-1ad01060b7c5#ref-52),53 (http://rsta.royalsocietypublishing.org/content/369/1936/594.full?sid=c3394c53-7f29-4bad-afd4-1ad01060b7c5#ref-53)]. The societal issues associated with re-creating life on Mars have been discussed in terms of assuming both that life has intrinsic value and alternatively that it has only instrumental value [55 (http://rsta.royalsocietypublishing.org/content/369/1936/594.full?sid=c3394c53-7f29-4bad-afd4-1ad01060b7c5#ref-55)]. The concept of assigning intrinsic value to life forms is perhaps most clearly stated in the first two tenets of deep ecology [56 (http://rsta.royalsocietypublishing.org/content/369/1936/594.full?sid=c3394c53-7f29-4bad-afd4-1ad01060b7c5#ref-56),57 (http://rsta.royalsocietypublishing.org/content/369/1936/594.full?sid=c3394c53-7f29-4bad-afd4-1ad01060b7c5#ref-57)]:
— The well-being of non-human life on Earth has value in itself. This value is independent of any instrumental usefulness for limited human purposes.
— Richness and diversity in life forms contribute to this value and are a further value in themselves.
When applied to Mars [58 (http://rsta.royalsocietypublishing.org/content/369/1936/594.full?sid=c3394c53-7f29-4bad-afd4-1ad01060b7c5#ref-58)], these principles argue that a biologically rich Mars is of more value than the fascinating but dead world we see today. Furthermore, a Martian biosphere populated by a second type of life would contribute to more diversity than one populated by transplants from Earth.
We know from observations of Mars that it does not have a rich global biosphere. Thus, if there is Martian life it is either dormant or surviving within some limited refugia. We do not know what would be the fate of that life if Earth organisms either were to colonize these existing refugia or were to be present as Mars was warmed in the first step of planetary restoration. It might be that co-habitation of Earth life and an alien type of Martian life is possible. However, the facts of biological competition for resources would seem to indicate that one form would dominate and drive the other to extinction. Thus, it would seem that the notion of the intrinsic worth of life and diversity of life would dictate that we will not allow contact between Martian life and Earth life until the implications of such contact are fully understood.
It is important to note that the basis for the ethical issues does not come from assigning intrinsic value to microbes per se. On Earth, we freely kill micro-organisms. The focus of the ethical concern is for a second type of life capable of independent biological and evolutionary development. This is true even if the specific organisms involved are only microbes.
6. Scientific implications :spy:
If we find evidence for a second genesis of life, we will certainly learn from the comparative study of the biochemistry, organismal biology and ecology of the alien life.
Even if an alternative life is based on carbon and water, it may have a different biochemical system. The number of distinct macromolecules that can be constructed from carbon is combinatorial, and thus very large. It may well be that life with a different origin and different history uses a different set of carbon-based molecules for its genetic and structural functions, rather than the DNA/RNA and proteins used for these functions by life as we know it. Having a second example of biochemistry would allow us to compare and contrast two biochemical systems both capable of sustaining life. From this comparative study, we might begin to understand which features of Earth biochemistry are universal and which features are particular to the historical developments on Earth.
In addition to comparisons at the biochemical level, it would be interesting to compare the cell structure and organization. Even more broadly, if we can observe or re-create entire ecosystems based on alien life, the potential for comparison is greatly expanded. In the widest sense, an alien biosphere composed of alien organisms using a different pattern of biomolecules gives the greatest scope for scientific return by comparison.
In addition to the biochemical, organismal and ecological levels, comparing life as we know it to a second genesis may help to address questions related to understanding the tree of life itself. One example question in this category is the fact that, of the two domains of life that are entirely microbial, only one (the bacteria) cause disease. The other domain (the archaea) are found in our intestines (about 1% of the human intestinal microbes are archaea) and in many ways are more similar to eukaryotes than bacteria. The archaea are also more closely related on the tree of life to eukaryotes than are bacteria. Yet, there is no known disease or infection caused by archaeal micro-organisms. A complete understanding of this may require an overall understanding of the tree of life that will most easily come with having another type of life to compare with.
[/URL]
7. Societal implications :peep:
The discovery of alien life, if alive or revivable, will pose fundamentally new questions in environmental ethics. Ethically and scientifically, we would do well to strive to support any alien life discovered as part of an overall commitment to enhancing the richness and diversity of life in the Universe.
The current field of astrobiology differs from other disciplines in space science in one fundamental way: astrobiology explicitly includes the question of what is the future of life in the Universe? This should motivate us to consider the long-term goal for human choices and actions with respect to life in the Universe. Human choices, while they should be informed by science, depend on ethical, economic and broad societal considerations. McKay [[URL="http://rsta.royalsocietypublishing.org/content/369/1936/594.full?sid=c3394c53-7f29-4bad-afd4-1ad01060b7c5#ref-50"]50 (http://rsta.royalsocietypublishing.org/content/369/1936/594.full?sid=c3394c53-7f29-4bad-afd4-1ad01060b7c5#sec-8)] has suggested that the long-term goal for astrobiology should be to enhance the richness and diversity of life in the Universe and that our choices and actions should reflect this goal.
McKay [50 (http://rsta.royalsocietypublishing.org/content/369/1936/594.full?sid=c3394c53-7f29-4bad-afd4-1ad01060b7c5#ref-50)] suggests that, while life is not the only source of value in the natural world, it is unique in that it is something of value that can be preserved, but it can also be spread without limit. If life has value then humans can create value and spread value as they spread life. In this sense, a focus on enhancing life connects to the deeply seated motivation for humans to be active creators, or co-creators, helping to shape and guide the existing creation and contributing to its diversity [50 (http://rsta.royalsocietypublishing.org/content/369/1936/594.full?sid=c3394c53-7f29-4bad-afd4-1ad01060b7c5#ref-50)].
While human action can contribute to life, it can also cause damage if unchecked. A relevant and current example is the biological contamination associated with exploration of potentially biological worlds like Mars. The search for life on Mars poses a logical dilemma: how to search for life without contaminating Mars with life from Earth. Such contamination poses two dangers. First, the search for life on Mars may give positive results because of life carried from Earth. Secondly, alien life forms native on Mars may be endangered by competition with transplanted Earth life.
Mars is interesting because it may have had life in the past and because it may be a place for life in the future. However, we are uncertain of the current biological state of Mars. There are at least three possibilities: (i) there is life on Mars that is distinctly different from life on Earth—a second genesis; (ii) there is life on Mars that is genetically related to life on Earth; and (iii) there is no life on Mars. Each of these possibilities implies distinctly different scenarios for how we can best explore Mars. Until we know which of these possibilities is correct, we must explore Mars in a way that keeps our options open with respect to future life.
One solution to this dilemma is that we must explore Mars in a way that is biologically reversible. Exploration is biologically reversible if it is possible and practicable to remove all life forms carried to Mars by that exploration. Because of the high ultraviolet and oxidizing conditions on the surface of Mars, the robotic and human exploration of the planet can be done in a way that is biologically reversible. We must be able to undo (‘ctrl Z’) our contamination of Mars if we discover a second genesis of life [51 (http://rsta.royalsocietypublishing.org/content/369/1936/594.full?sid=c3394c53-7f29-4bad-afd4-1ad01060b7c5#ref-51)–53 (http://rsta.royalsocietypublishing.org/content/369/1936/594.full?sid=c3394c53-7f29-4bad-afd4-1ad01060b7c5#ref-53)].
It has been proposed that re-creating a biosphere on Mars (e.g. [54 (http://rsta.royalsocietypublishing.org/content/369/1936/594.full?sid=c3394c53-7f29-4bad-afd4-1ad01060b7c5#ref-54)]) based on indigenous life, or, lacking indigenous life, based on Earth life, would contribute to expanding the richness and diversity of life in the Universe [52 (http://rsta.royalsocietypublishing.org/content/369/1936/594.full?sid=c3394c53-7f29-4bad-afd4-1ad01060b7c5#ref-52),53 (http://rsta.royalsocietypublishing.org/content/369/1936/594.full?sid=c3394c53-7f29-4bad-afd4-1ad01060b7c5#ref-53)]. The societal issues associated with re-creating life on Mars have been discussed in terms of assuming both that life has intrinsic value and alternatively that it has only instrumental value [55 (http://rsta.royalsocietypublishing.org/content/369/1936/594.full?sid=c3394c53-7f29-4bad-afd4-1ad01060b7c5#ref-55)]. The concept of assigning intrinsic value to life forms is perhaps most clearly stated in the first two tenets of deep ecology [56 (http://rsta.royalsocietypublishing.org/content/369/1936/594.full?sid=c3394c53-7f29-4bad-afd4-1ad01060b7c5#ref-56),57 (http://rsta.royalsocietypublishing.org/content/369/1936/594.full?sid=c3394c53-7f29-4bad-afd4-1ad01060b7c5#ref-57)]:
— The well-being of non-human life on Earth has value in itself. This value is independent of any instrumental usefulness for limited human purposes.
— Richness and diversity in life forms contribute to this value and are a further value in themselves.
When applied to Mars [58 (http://rsta.royalsocietypublishing.org/content/369/1936/594.full?sid=c3394c53-7f29-4bad-afd4-1ad01060b7c5#ref-58)], these principles argue that a biologically rich Mars is of more value than the fascinating but dead world we see today. Furthermore, a Martian biosphere populated by a second type of life would contribute to more diversity than one populated by transplants from Earth.
We know from observations of Mars that it does not have a rich global biosphere. Thus, if there is Martian life it is either dormant or surviving within some limited refugia. We do not know what would be the fate of that life if Earth organisms either were to colonize these existing refugia or were to be present as Mars was warmed in the first step of planetary restoration. It might be that co-habitation of Earth life and an alien type of Martian life is possible. However, the facts of biological competition for resources would seem to indicate that one form would dominate and drive the other to extinction. Thus, it would seem that the notion of the intrinsic worth of life and diversity of life would dictate that we will not allow contact between Martian life and Earth life until the implications of such contact are fully understood.
It is important to note that the basis for the ethical issues does not come from assigning intrinsic value to microbes per se. On Earth, we freely kill micro-organisms. The focus of the ethical concern is for a second type of life capable of independent biological and evolutionary development. This is true even if the specific organisms involved are only microbes.