There’s a book review in the Guardian that gives a spotlight to a fascinating idea – shadow ecology, a stealth biosphere based on an alternative organic chemistry, undetected, right here on Earth, not even imagined until now.
This idea is perfectly congruent with natural selection. At the point when life was formed on Earth there was a lot of biochemistry, energy and time. Most of the history of life on Earth is dominated by single-cell life. By many measures bacteria are still the dominant mode of existence. Multi-cellular life is the comparative exception. There would be no currently available niches for multi-cellular shadow life.
Our conception of life has expanded. Life has been discovered at the bottom of the ocean living in endothermic ecosystems, in extremely acidic or saline conditions, under ice sheets and in deserts. But this life uses the same basic chemistry as our own. If a shadow biosphere exists why have we failed to find it after a more century of biological science? It might be because scientists have been suffering from a lethal theoretical conceit but it might be because it’s not there.
Our conception of life has expanded. Life has been discovered at the bottom of the ocean living in endothermic ecosystems, in extremely acidic or saline conditions, under ice sheets and in deserts. But this life uses the same basic chemistry as our own. If a shadow biosphere exists why have we failed to find it after a more century of biological science? It might be because scientists have been suffering from a lethal theoretical conceit but it might be because it’s not there.
The link between theory and reality is investigation, and there are some tests being proposed to test for possible shadow-life. An example, life as we know it uses the left half of DNA strands as code. “Right-handed” organisms in a culture should respond to right-handed amino acids. Finding creatures using entirely different replicating molecule would be even more exciting.