Origin of Life

Kolmogorov Complexity, String Information, Panspermia and the Fermi Paradox

Bit strings rather than byte files can be a mode of transmission both for intelligent signals and for travels of extraterrestrial life. Kolmogorov complexity, i.e. the minimal length of a binary coded string completely defining a system, can then, due to its universality, become a key concept in the strategy of the search of extraterrestrials. Evaluating, for illustration, the Kolmogorov complexity of the human genome, one comes to an unexpected conclusion that a low complexity compressed string - analog of Noah's ark - will enable the recovery of the totality of terrestrial life. The recognit…

Critique on Vindication of Panspermia

In January 2001, air samples were collected from Earth's stratosphere. From these air samples, cultures of three microorganisms were obtained. It was reasoned that these microorganisms are of cometary origin and thereby cometary panspermia stood vindicated. The fact that these microorganisms had essentially the same characteristics as terrestrial microorganisms was explained using cometary panspermia. Here, the findings are reinterpreted in the light of niche ecology and adaptations. It is asserted that the microorganisms captured from the stratosphere cannot be of cometary origin as they are …

Cosmic Biology in Perspective

A series of astronomical observations obtained over the period 1986 to 2018 supports the idea that life is a cosmic rather than a purely terrestrial or planetary phenomenon. These include (1) the detection of biologically relevant molecules in interstellar clouds and in comets, (2) mid-infrared spectra of interstellar grains and the dust from comets, (3) a diverse set of data from comets including the Rosetta mission showing consistency with biology and (4) the frequency of Earth-like or habitable planets in the Galaxy. We argue that the conjunction of all the available data suggests the opera…

地球的自然外星生命传播：太阳系和恒外来源的运输、防护和生存极限

Natural Lithopanspermia to Earth: Transport, Shielding, and Survival Limits for Solar-System and Extrasolar Donor Classes

研究探讨了非地球来源生命在经历运输、防护和生存限制后是否能竞争地球起源，提出太阳系内早期火星可能提供一种硬 panspermia 途径，而其他外星来源则不具竞争力，同时指出软 panspermia 更可能促进地球早期生物起源的化学富集。

Life Before Earth

An extrapolation of the genetic complexity of organisms to earlier times suggests that life began before the Earth was formed. Life may have started from systems with single heritable elements that are functionally equivalent to a nucleotide. The genetic complexity, roughly measured by the number of non-redundant functional nucleotides, is expected to have grown exponentially due to several positive feedback factors: gene cooperation, duplication of genes with their subsequent specialization, and emergence of novel functional niches associated with existing genes. Linear regression of genetic …

The Origin of Life in the Universe

Terrestrial and extraterrestrial theories of the origin of life are discussed in the light of latest observations. The available data suggest a dual mode of origin, some of the ingredients, including possibly sugars, were brought to earth from outer space, which combined with other ingredients, such as proteins, already available on the earth leading to the formation of life.