Encoded Universe

April 23, 2011

The study of origin of life (pg. 4) on Earth is still a perplexing subject for academia because its unlikely scientists will never definitely be able to confirm or deny any theories about our origin simply because we have no evidence to support or refute any claims. While there can never be an answer to any of these questions about where we came from, theories, speculations, and wild guesses abound from scientists who study the matter. Ever if we do manage to one day build life from scratch, we will never be able to prove that life on Earth was formed in the same process as a manufactured cell. Most scientists agree that life arose from the chemical evolution of organic molecules and that a primitive selection process favored self-replicating organic systems that could reproduce themselves more efficiently. We’ll highlight a few of the most interesting theories and compare the merits of these ideas. Eventually these processes would lead to something we would consider to be alive; something that can no longer be considered solely a chemical reaction, but start to resemble a biological system.

A researcher from the University of Glasgow advanced a kaolin-clay hypothesis for primitive life. His theory goes that the earliest forms of life were made from self-replicating silicate crystals; not truly alive, but showing a remarkable level of organization. These clay crystals could have been the precursor to all organisms and could have shown a rudimentary form of metabolism and self-replication. Kaolin clay forms in a specific lattice arrangement that is preserved even as these minerals grow and the right minerals dissolved in solution speed up the rate at which these crystals form in the presence of water. This diet of dissolved minerals in water could be thought as analogous to metabolism in a living creature. The increasing complexity of the structures of these crystals served as the mold for increasingly complex organic compounds. Further research revealed that when a certain crystal is sliced in half and dipped in an aqueous solution, the mineral is that regrows to complete the rest of the crystal and will copy the same imperfections of the parent crystal, while forming new imperfections along the way. This could suggest a weak form of natural selection and a primitive form of heredity; because imperfections in the crystal get carried with each copy to the next, there is said to be some form of inheritance of characteristics. And because some crystals would grow faster than others based on the mineral water available to them and the robustness of their crystal lattice, more stable minerals in favorable environments would grow faster than those in poor environments, and dominate the environment.

Some researchers have posited that the origin of life suggests that a primitive cell membrane appeared first and engulfed the cellular machinery that developed later. Others suggest that the cellular mechanisms had to have come first and that their vessel was created later one. Scientists studying the origin of life are loosely divided into two camps; those who believe metabolism occurred first, or those who believe genetics were developed first. So the research in this field focuses on two different approaches (pg. 2) to this problem; some start from scratch and try to build a self-replicating entity while others take a top-down approach and strip a living cell of all but the most necessary machinery in an attempt to figure out what mechanisms working within the cell are the most fundamental and hence the most primeval.

Researchers looking at Stanley Miller’s research into the origin of life have wondered if the prebiotic environment interacted with the geology of the early Earth. After researching common minerals, they found that the mineral borax can stabilize the ribose sugar in RNA, allowing significant quantities of RNA accumulate in the environment in levels useful to biology. As the authors suggest, this could alter our understanding of the origin of life because borax doesn’t appear in a warm little pond like Darwin suggested, or even in a hydrothermal vent like some modern researchers posit; it places our origin in the arid environment because borax is a salt found in deserts. In Peter Ward’s book Life As We Do Not Know It, Ward cites speculation by some researchers who believe the ingredients for life or even life itself may have come from the drier planet Mars, which would have mirrored Earth in some ways around the time that life was forming on our planet. If the chemical ingredients for life or even a partially-assembled cell arrived on Earth from Mars via a comet impact, it could have a profound impact on our understanding of life; if we can partially trace our origins back to Mars, does that make us Martians?

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