Questions about Life and Space

Is there life in space?  Is life from space?  Is the Earth a closed ecological system?

In the 19th century, Arrhenius proposed the idea that life could have come from space.  This echoed some ancient ideas as well, that life had come to Earth from elsewhere.  Such ideas were expressed by Empedocles, although perhaps he was talking about our spirits, not the cellular ancestors of Earthly life.

Astronomer Fred Hoyle noted some years ago, in a book called “Life Clouds,” that radiation and light coming off of or through interstellar dust was consistent with dust containing bacterial cells.  I don’t think he was suggesting that dust consists entirely of the remains of dessicated bacteria, but just that cellular life or the remains of such life could be present in the dust of interstellar space.

Discoveries continue to mount for organic molecules in various bodies, such as comets, asteroids, and various gas and dust clouds.  All manner of molecules significant for life  have been found, including sugars and porphyrin rings, which are found in chlorophyll and hemoglobin.  Current beliefs in mainstream science focus on inorganic means for the creation of these molecules, but even so, the presence of such molecules makes it easier to believe that life could more easily evolve elsewhere in the universe.  For some of these molecules, such as amino acids, there are two mirror image forms that can exist. In non-living matter, equal amount of the two mirror image forms were expected to exist.  It was once thought a sign of living matter would be the discovery of a prevelance of one or the other (left-handed or right-handed) forms. Some of these discoveries of organic molecules on meteorites reveal the preference for one mirror image over the other.  Is this an indication of a living origin, or an as-yet unknown non-biological way to create a preference for one form over the other?

Bacteria has also been shown to have survived in space, on the outer surfaces of some probes and vehicles.  Also, recent experiments have been done by Chandra Wickramsinghe at high altitudes to collect possible evidence of bacteria falling into the upper atmosphere, with interesting results that seem to support the idea of novel bacteria arriving from space.

Hoyle also speaks about comets having once been warmer, warmed by the power of radioactivity when they were younger bodies, before the most radioactive isotopes had decayed to more stable ones.  Comets often consist of a lot of water and organic material.  Hoyle’s idea was that comets may have incubated bacterial life in their early days, having picked up remnant bacteria or viruses from interstellar dust particles or other fragments from interstellar space.  The idea then is that comets could deliver this material into the inner solar system as they swing through and are broken up by the sun’s heat, where they persist in dusty trails that follow their orbits.  Old dust tails of comets then lead to meteor showers on Earth, where the viruses or bacteria, or at the very least the genes that make up life, have a chance to grow and thrive again.   Even if the genetic fragments that arrive are not themselves living, it is theorized that they could be taken up by bacteria and incorporated into their genomes.  It is accepted in microbiology now that genes are readily transferred between different types of bacteria, and between bacteria and viruses.  New genes arriving from space could be incorporated into the genomes of existing terrestrial bacteria.

The idea of life coming from space is a viable idea.  If so, the implications are significant.  For the origin of life, the question changes radically from the puzzle of how life could have gotten started so quickly on the early Earth.  The new question puts the origin of life possibly very far away, and possibly with a much longer timeframe, and instead, the questions become more about how various gene and RNA fragments, organic and inorganic molecules, and other seeds of life could arrive on the Earth and start to assemble and reproduce.

Thinking about the question of extraterrestrial influence also changes the situation radically.  If we allow the possibility of extraterrestrial visitation, then the question of Earth as an isolated ecosystem changes radically.  Just as the visitations of European ships to remote islands, such as Hawaii, changed the ecology of those islands forever, so too could the visitations of extraterrestrials to the Earth have changed the ecology of the Earth.

This is the question of so-called “directed panspermia”, that Francis Crick wrote about.  Was the Earth deliberately or accidentally seeded by intelligent life from elsewhere?  In the original paper, the scenario was not played up, but rather mentioned offhand, as if life on Earth had evolved accidentally from the garbage left behind by a chance exploratory landing.  The other possibility, of deliberate seeding, is very interesting, and is the focus of my current thinking.  If indeed extraterrestrial life has been coming and going from our world for many millenia if not millions of years, then the entire ecosystem is a much greater thing than what we see from Earth.  The major families of plants, animals, fungi, and all kingdoms of life, from the tiniest microorganism to the largest of the animals could be widespread throughout space.

The fossil record on Earth shows some of the species that were present here on Earth, but many species not on the Earth that might be relevant to putting together an evolutionary tree could be missing not because of mere circumstance, but because these evolutionary steps occurred elsewhere than on the Earth.

 Periods of rapid increase in diversity of life on Earth could be the result of increased interstellar visitation, or deliberate periods of seeding of different animals and plants.  The Cambrian explosion, for example, could be such a time.  The Cambrian explosion is when many of the major groups of animals and plants appeared.

The other question of interest is the appearance of reported extraterrestrial visitors. Contactees have reported beings that are bipedal, and have many resemblances to human, or primate, life.  Some probable contactees, such as Billy Meier, have seen beings, such as the Pleiadeans or Plejarans, who are so close to human in appearance that they could possibly pass as human on our world.  If Earth is not a closed system, and missing links in Earth’s evolutionary tree of life are to be expected elsewhere in the universe, it should be no surprise that relatives of ours might be here visiting us now.

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