The Origin of Life
“A functioning cell must be entirely correct at once, in all its complexity.” ~ German chemist Wilhelm Huck
▫ Bombardment from space seeded the ingredients for life on Earth. Meteorites commonly contain water, amino acids, and nucleobases.
▫ More than organic ingredients may have rained down. Life on Earth might have traveled from Mars. Alternately, life could have even come in from outside the solar system, traveling millions of years before finding a home.
▫ However mathematically improbable, life originated on Earth as soon as environmental conditions permitted.
The complex combination of manifestations and properties so characteristic of life must have arisen in the process of the evolution of matter. ~ Alexander Oparin
▫ If life originated domestically, it probably began on or in the warm ocean bed, most likely the ancestor to archaea, with bacteria arising shortly thereafter. Archaea are archaic – a likely direct descendant of the earliest life.
▫ The force of coherence that composes Nature was crucial in begetting life, notably in the sophistication required for coordinated cellular organization, metabolic processes, and replication.
Life requires chemistry, but the properties of the living state emerge from the dynamical properties of that chemistry, including the temporal and spatial organization of molecular networks and their information management. Life uses information to construct itself. The development of networks over time may be more important than the specific chemical nature of their molecular components. A concept of information relevant to biological organization may be essential to identifying these networked processes. ~ English chemist Leroy Cronin & Sara Imari Walker
▫ Archaea and bacteria are primitive prokaryotes that both use DNA, but have distinctive differences indicating independent origination.
▫ By infecting primitive life with DNA, viruses created what appears as a universal common ancestor. This homogenization of life at the cellular level created the platform for the intimate interrelations among various life forms that defines Earth’s biosphere.
“We have no evidence whatsoever for any life beyond Earth.” ~ Paul Davies
▫ With many trillions of planets in the universe, the probability of Earth being the only planet with life is negligible. Life exists elsewhere. (This conclusion is supported by the probability that life on Earth independently arose innumerable times in a variety of habitats.)
▫ Given that organic molecules are naturally occurring in space, and reflect energy economics prescribed by physics and chemistry, life elsewhere likely follows Earth’s gyre.
▫ The most intriguing questions about extraterrestrial life go to early evolution. Do viruses universally evolve to nudge homogeneity as they did on Earth? If not, do fundamentally incompatible life forms evolve, creating an entirely different biospheric dynamic than on Earth? That would happen if gene sharing was not as ubiquitous among organisms as it has been on Earth.