title: Theoretical hypotheses for the origin of life in protoplanetary disks
title: Theoretical basis hypotheses for the origin of life in protoplanetary disks
titleType: AlternativeTitle
Creators: name: LI, XIAOMING
Publisher: name: Zenodo
Year: 2024
Subjects: the origin of life
protoplanetary disk
biological evolution
the universe

description: The primary purpose of this review is to present hypotheses. In this theoretical study exploring the origin of life, the main argument is that life on Earth may not have originated on Earth but rather in the protoplanetary disk at the time of the solar system's formation. This hypothesis focuses on the discoveries and problems encountered by scientists in the limited field of origin of life research and proposes possible solutions. These discussions include characteristics of protoplanetary disks and their complex systems that appear more conducive to life's origin. The water paradox for the origin of life on Earth may be resolved on protoplanetary disks; the chiral preference for amino acids on Earth may have originated on protoplanetary disks. The molecular composition of protoplanetary disks may be more conducive to explaining the origin of life; the large number of organic molecules observed in cosmic dust may have originated on protoplanetary disks. The ultraviolet resistance of life on Earth may have originated in the protoplanetary disk. Life may have originated on protoplanetary disks through archaeological analysis of the Morrison and other meteorites. Analyze literature on the last universal common ancestor to explore the possibility that life originated on protoplanetary disks. Finally, model the possible origin of life on protoplanetary disks and explain the potential origin of life on protoplanetary disks. Discussions of the theoretical basis for the origin of life on protoplanetary disks are limited to theoretical hypotheses. Hopefully, these theoretical discussions will provide scientists engaged in the origin of life research with a new vision of the origin of life research. These discussions will contribute to the future development of the origin of life research.
description: The primary purpose of this review is to present hypotheses. In this theoretical study exploring the origin of life, the main argument is that life on Earth may not have originated on Earth but rather in the protoplanetary disk at the time of the solar system's formation. This hypothesis focuses on the discoveries and problems encountered by scientists in the limited field of origin of life research and proposes possible solutions. These discussions include characteristics of protoplanetary disks and their complex systems that appear more conducive to life's origin. The water paradox for the origin of life on Earth may be resolved on protoplanetary disks; the chiral preference for amino acids on Earth may have originated on protoplanetary disks. The molecular composition of protoplanetary disks may be more conducive to explaining the origin of life; the large number of organic molecules observed in cosmic dust may have originated on protoplanetary disks. The ultraviolet resistance of life on Earth may have originated in the protoplanetary disk. Life may have originated on protoplanetary disks through archaeological analysis of the Morrison and other meteorites. Analyze literature on the last universal common ancestor to explore the possibility that life originated on protoplanetary disks. Finally, model the possible origin of life on protoplanetary disks and explain the potential origin of life on protoplanetary disks. Discussions of the theoretical basis for the origin of life on protoplanetary disks are limited to theoretical hypotheses. Hopefully, these theoretical discussions will provide scientists engaged in the origin of life research with a new vision of the origin of life research. These discussions will contribute to the future development of the origin of life research.
description: A.      Modeling the possible origin of life on protoplanetary disks

 

 It is crucial to develop a model for the possible origin of life on a protoplanetary disk. It is believed to present here my preliminary ideas. The protoplanetary disk contains a large number of CHNOPS elements, which are the main components of living matter and is rich in various "metals" including, but not limited to, alkali metals (Na, K), alkaline-earth metals (Mg, Ca), transition metals, post-transition metals (Zn, Al), and lanthanides (La-Lu), etc. The protoplanetary disk has many CHNOPS elements, which are the main components of living matter. The protoplanetary disk also contains many substances that protocells, such as hydrogen, helium, water, methane, ammonia, carbon dioxide and carbon monoxide, can metabolize. Probably, the temperature was also relatively high. On the dusty surface of the protoplanetary disk, due to the possible favourable physical and chemical conditions, the synthesis of the most basic organic molecules began and was followed by the synthesis of amino acids, nucleotides, fatty acids, phospholipids, cholesterol, sugars, and glycolipids. After the generation of these substances on the dusty surface of the protoplanetary disk, the dust particles, which could generate life molecules on these surfaces, began accumulating due to physical effects. The result is a carbonaceous nephrite that is relatively isolated from the outside world but can exchange gases and other substances containing water, does not deposit water, is half-wet and half-dry, and contains microscopic pores inside, large or small.

        As the temperature of the protoplanetary disk decreases, this facilitates the self-assembly and self-organization of organic molecules to form more complex molecules. Different amino acids spontaneously combine, extend, and fold to form proteins. The phosphodiester bonds between nucleotides are condensed and dehydrated to form DNA or RNA. At the same time, the membrane structure of the protocells is also formed in these microscopic pores, and the protocell membranes co-evolved with proteins DNA and RNA. The protoplasts contain DNA, RNA, proteins, and proteases for metabolism. The required nutrients are water, hydrogen, methane, carbon monoxide, etc., all available in the protoplanetary disk. Snowlines, changes in C/O ratio, chemical gradients, and redox chemistry in the protoplanetary disk are all relevant to cellular metabolism. Protocells in protoplanetary disks continue to evolve in response to changes in the environment of the protoplanetary disk.

        There may be two ways in which cells in protoplanetary disks splash down to Earth with meteorites. First, the protocells enter the Earth directly with the meteorite and continue replicating and evolving. The second, protocells in carbonaceous chondrites of the protoplanetary disk, froze in the protoplanetary disk as the temperature decreased. Later, as the meteorite splashed to Earth and reached the hydrothermal vents on the seafloor, the proto-cells in the meteorite recovered and continued to replicate and evolve. This process is very much like freezing cells with liquid nitrogen in a laboratory, where the cooling of the cells is a gradual process. The liquid nitrogen temperature is generally quite a bit higher than the absolute zero of the Universe, but the principle is the same. Resuscitating cells, on the other hand, is a rapid process. Like a meteorite splashed down on the Earth, the temperature inside the meteorite from absolute zero to the hydrothermal vents on the planet, the rapid warming to maintain the recovery of cells inside the meteorite.
description: This paper briefly summarizes the results of the origin of life experiments conducted by scientists in different fields through different perspectives. As examined, evaluated and interpreted the results of scientific experiments on the origin of life undertaken by previous generations of scientists from various perspectives. Based on the findings of the scientific experiments conducted by earlier scientists, It presents and analyzes different theories of the origin of life on Earth. It argues that the trustworthy source of life on Earth may not have originated on Earth, but that life on Earth may have originated on the protoplanetary disk. In other words, the roots of what Darwin called the tree of life on Earth did not originate on Earth but may have originated in the protoplanetary disk. The protocells of life on Earth may also have originated in the protoplanetary disk. The Earth may not have been the source of life, and life on Earth could only have been copied, reproduced, and evolved. This description is a narrow concept of the origin of life.

This concept can also be generalized to other planets in the solar system because all planets in the solar system were born in the same protoplanetary disk. It is just that different planets have different positions in the protoplanetary disk and various distances from the Sun. The Earth is probably in the best habitable zone. If life is found on other planets in our solar system, the primary life forms should be roughly the same as on Earth. For example, the chirality of amino acids should be predominantly left-handed (L). The coding rules for protein translation should also be the same on other planets in the solar system as on Earth (if there is living matter or life on other planets in the solar system)

The broad concept of the origin of life can be extended to the origin of life throughout the Universe. Its main principle is an extension of the protoplanetary disk theory of the birth of life, i.e., that all cosmic life (if it can be found) or cosmic organic compounds came from the cloud disk at the birth of this star and from the protoplanetary disks that may have been born subsequently. It is the reason for the origin of the cosmic organic molecules we observe. The production of these organics is physically, chemically and biochemically consistent with the origin of life in the Earth's protoplanetary disk. The difference, however, is that the direction of rotation of the protostellar cloud disks of other stars may produce different life-giving materials depending on their celestial conditions. The Earth is in the galaxy's habitable zone, and life has undergone a series of inevitable and accidental factors running through it from its origin to its present evolution into humans.