Panspermia
is an old theory of the origin of life. Panspermia is simply the
theory that earthly life originated when life came from outer space. Early advocates of the theory suggested that life may have come to Earth when spores drifted through interstellar space. Later advocates of the theory would sometimes suggest that perhaps comets brought life to Earth.
I can understand some mathematical reasons why someone might be a
little attracted to a theory of panspermia. Let us imagine that the
probability of life appearing from some accidental combination of
chemicals is 1 in X per billion years per planet, where X is some
number such as a trillion. If we imagine that life could have
appeared on any of a 100 billion planets in our galaxy, and somehow
found its way to Earth, then the improbability of life appearing on
Earth might be greatly reduced. For example, if X is a trillion, and
there are 100 billion planets in our galaxy where life might have
arisen, then the chance of life eventually ending up on Earth
(through some cosmic migration) might be much less than 1 in a
trillion.
Unfortunately,
a realistic estimate of the chance of life appearing from chemicals
due to merely accidental processes will result in a probability
estimate very, very many orders of magnitude smaller than 1 in a
trillion. A more realistic estimate would be something on the order
of 1 in 101000,
where 101000 is 10 followed by about a thousand zeroes. With a
probability that low, it doesn't help very much if you imagine that
life might come from somewhere else in our galaxy. Such an idea
might reduce the unlikelihood by 100 billion times, but when you have
a likelihood such as 1 in 101000 that means very little.
A probability of 1 in 101000 increased by 100 billion
times is still a way-too-small number such as 1 in 10990.
A
theory of panspermia has long been presented at the website
www.panspermia.org. In this
well-organized site with quite a few pages, we have a theory that is
called Cosmic Ancestry. At the start of a page introducing the
theory, we are told this:
“Cosmic
Ancestry is a new theory pertaining to evolution and the origin of
life on Earth. It holds that life on Earth was seeded from space, and
that life's evolution to higher forms depends on genetic programs
that come from space.”
Oops,
we are getting a sign right at the beginning that Cosmic Ancestry is
on the wrong track. The idea that the appearance of higher forms of
life can be explained by “genetic programs” is wrong. DNA
(consisting of genes) does not contain any program or algorithm for
making an organism. DNA is not a blueprint or a recipe specifying the
overall structure of an organism. DNA does not specify how to make
any of the organs of an organism, and does not even specify how to
make any of the cell types of an organism. DNA merely specifies low-level chemical information such as the polypeptide sequences (chains of amino acids) used by proteins. Massimo Pigliucci (mainstream author of numerous scientific papers on evolution) has stated that "old-fashioned metaphors like genetic blueprint and genetic programme are not only woefully inadequate but positively misleading." Debunking the idea of DNA as a program consisting of algorithms, biologist Denis Noble states the following:
"No complete algorithms can be found in the DNA sequences. What we find is better characterised as a mixture of templates and switches. The ‘templates’ are the triplet sequences that specify the amino acid sequences or the RNA sequences."
The
myth that DNA is some kind of blueprint or recipe for making
organisms (or a program or set of programs for making organisms) is
something I call the Great DNA Myth. This myth was spread by
orthodox Darwinists soon after DNA was discovered, because such
thinkers needed such an idea to bolster their boasts that an
explanation for the origin of species had been discovered. On pages such as this one, the
Cosmic Ancestry site expresses great skepticism about the main
explanatory claims of Darwinism. But the source of the Cosmic Ancestry theory seems to have swallowed hook, line and sinker one of the biggest myths peddled by Darwinists, the myth that there are genetic programs that specify the structures of organisms.
On the same introductory page, we have some information that is not fully accurate:
"Starting in the 1970s, British astronomers Fred Hoyle and Chandra Wickramasinghe rekindled interest in panspermia. By careful spectroscopic observation and analysis of light from distant stars they found new evidence, traces of life, in the intervening dust. They also proposed that comets, which are largely made of water-ice, carry bacterial life across galaxies and protect it from radiation damage along the way. One aspect of this research program, that interstellar dust and comets contain organic compounds, has been pursued by others as well. It is now widely accepted that space contains the 'ingredients' of life."
It is not at all true that Hoyle and Wickramasinghe found "traces of life" in outer space. Although astronomers such as Carl Sagan kept telling us that "the stuff of life is everywhere," there was no sound basis for such claims. There are virtually no signs of building blocks of life in outer space. The building blocks of life are proteins, which have never been discovered in outer space. The building blocks of proteins (what can be called building blocks of the building blocks of life) are twenty types of amino acids used by living things. None of the twenty amino acids used by living things has been discovered in space, other than the simplest amino acid, glycine (which was not found in space while Sagan lived). None of the nucleosides or nucleotides that make up DNA or RNA has ever been found in space.
If life came here from outer space, how did it get here? On the page "Comets: The Delivery System," the Cosmic Ancestry site offers an answer of comets. This is not a terribly plausible theory, given that any life existing in a comet would be likely to be destroyed by the incredible violence of the comet striking the Earth, an event with almost as much kinetic energy as an asteroid collision. The site seems unwilling to endorse any theory of intelligent visitors from another planet deliberately setting up life or new species here on our planet. Such a theory (called directed panspermia) would seem to be a more promising approach. But the Cosmic Ancestry site does not seem interested in such an idea. If genetic information had come to our planet from comets, it is hard to think of any credible path by which such information could have ended up in the genomes of earthly organisms. If an animal drinks a little water coming from comet, that wouldn't cause some gene from the comet to end up in the animal's DNA.
On the question of how life first orginated, the Cosmic Ancestry offers the strange answer that life has always existed. The site states the following:
"Cosmic Ancestry implies, we find, that life can only descend from ancestors at least as highly evolved as itself. And it means, we believe, that there can be no origin of life from nonbiological matter. Without supernatural intervention, therefore, we conclude that life must have always existed."
Such claims are very inconsistent with modern cosmology, which tells us that the universe has not always existed, and that the universe suddenly began about 13 billion years ago in a state of unimaginable heat and density which would have destroyed any life. Even those cosmologists who believe (with no real justification) that the Big Bang was a Big Bounce (from a previous cycle of the universe) believe that the early universe must have been so fantastically dense and hot that no life could have persisted through the Big Bang. The claim that life has always existed is therefore a credibility issue for the theory of Cosmic Ancestry.
The theory of Cosmic Ancestry seems like one of the less persuasive versions of panspermia. A rather more viable panspermia theory would be a theory that imagined the intervention of visiting intelligent extraterrestrials. You can always explain more by imagining some kind of intelligent agency than by imagining blind natural processes. But even that type of theory (what is called a directed panspermia theory) would have its shortfalls. You can imagine a million and one visitations by ancient astronauts, but that doesn't explain how a newly fertilized egg is able to grow from a mere speck to become a full-sized human. Since there are no genetic programs that explain such a thing, the fact of morphogenesis and embryogenesis is the most gigantic shortfall both for orthodox biology and the theory of Cosmic Ancestry. Then there is the reality that the main capabilities and phenomena of the human mind and human memory are not explained by anything in the human brain, contrary to the boasts of today's biologists. You cannot get around such a shortfall by any theory of "stuff from space." When it comes to explaining consciousness, comprehension and enormously organized systems of coordinated complexity, comets don't cut it.
"Starting in the 1970s, British astronomers Fred Hoyle and Chandra Wickramasinghe rekindled interest in panspermia. By careful spectroscopic observation and analysis of light from distant stars they found new evidence, traces of life, in the intervening dust. They also proposed that comets, which are largely made of water-ice, carry bacterial life across galaxies and protect it from radiation damage along the way. One aspect of this research program, that interstellar dust and comets contain organic compounds, has been pursued by others as well. It is now widely accepted that space contains the 'ingredients' of life."
It is not at all true that Hoyle and Wickramasinghe found "traces of life" in outer space. Although astronomers such as Carl Sagan kept telling us that "the stuff of life is everywhere," there was no sound basis for such claims. There are virtually no signs of building blocks of life in outer space. The building blocks of life are proteins, which have never been discovered in outer space. The building blocks of proteins (what can be called building blocks of the building blocks of life) are twenty types of amino acids used by living things. None of the twenty amino acids used by living things has been discovered in space, other than the simplest amino acid, glycine (which was not found in space while Sagan lived). None of the nucleosides or nucleotides that make up DNA or RNA has ever been found in space.
If life came here from outer space, how did it get here? On the page "Comets: The Delivery System," the Cosmic Ancestry site offers an answer of comets. This is not a terribly plausible theory, given that any life existing in a comet would be likely to be destroyed by the incredible violence of the comet striking the Earth, an event with almost as much kinetic energy as an asteroid collision. The site seems unwilling to endorse any theory of intelligent visitors from another planet deliberately setting up life or new species here on our planet. Such a theory (called directed panspermia) would seem to be a more promising approach. But the Cosmic Ancestry site does not seem interested in such an idea. If genetic information had come to our planet from comets, it is hard to think of any credible path by which such information could have ended up in the genomes of earthly organisms. If an animal drinks a little water coming from comet, that wouldn't cause some gene from the comet to end up in the animal's DNA.
On the question of how life first orginated, the Cosmic Ancestry offers the strange answer that life has always existed. The site states the following:
"Cosmic Ancestry implies, we find, that life can only descend from ancestors at least as highly evolved as itself. And it means, we believe, that there can be no origin of life from nonbiological matter. Without supernatural intervention, therefore, we conclude that life must have always existed."
Such claims are very inconsistent with modern cosmology, which tells us that the universe has not always existed, and that the universe suddenly began about 13 billion years ago in a state of unimaginable heat and density which would have destroyed any life. Even those cosmologists who believe (with no real justification) that the Big Bang was a Big Bounce (from a previous cycle of the universe) believe that the early universe must have been so fantastically dense and hot that no life could have persisted through the Big Bang. The claim that life has always existed is therefore a credibility issue for the theory of Cosmic Ancestry.
The theory of Cosmic Ancestry seems like one of the less persuasive versions of panspermia. A rather more viable panspermia theory would be a theory that imagined the intervention of visiting intelligent extraterrestrials. You can always explain more by imagining some kind of intelligent agency than by imagining blind natural processes. But even that type of theory (what is called a directed panspermia theory) would have its shortfalls. You can imagine a million and one visitations by ancient astronauts, but that doesn't explain how a newly fertilized egg is able to grow from a mere speck to become a full-sized human. Since there are no genetic programs that explain such a thing, the fact of morphogenesis and embryogenesis is the most gigantic shortfall both for orthodox biology and the theory of Cosmic Ancestry. Then there is the reality that the main capabilities and phenomena of the human mind and human memory are not explained by anything in the human brain, contrary to the boasts of today's biologists. You cannot get around such a shortfall by any theory of "stuff from space." When it comes to explaining consciousness, comprehension and enormously organized systems of coordinated complexity, comets don't cut it.
Systems this complex are all over the place in biology
Doesn't the theory of directed panspermia just push the question back, after all if aliens created us how were they created.
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