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If the deep marine hydrothermal setting was the site for the origin of life, then abiogenesis could have happened as early as 4.0-4.2 Gya. If life evolved in the ocean at depths of more than ten meters, it would have been shielded both from impacts and the then high levels of ultraviolet radiation from the sun.
The Origin and Nature of Life on Earth: The Emergence of the Fourth Geosphere (2016) is a book by Eric Smith and biophysicist Harold J. Morowitz which provides an introduction to origins of life research via a review of perspectives from a variety of fields active in this research area, including geochemistry, biochemistry, ecology, and microbiology.
Antonie van Leeuwenhoek. Traditional religion attributed the origin of life to deities who created the natural world. Spontaneous generation, the first naturalistic theory of abiogenesis, goes back to Aristotle and ancient Greek philosophy, and continued to have support in Western scholarship until the 19th century. [15]
The average life expectancy at birth rises gradually until it exceeds 50 years. It is during this stage that fertility becomes the crucial factor in population growth. In 1998 Barrett et al. [ 7 ] proposed two additional phases in which cardiovascular diseases diminish as a cause of mortality due to changes in culture, lifestyle and diet, and ...
A scenario is a set of related concepts pertinent to the origin of life (abiogenesis), such as the iron-sulfur world. Many alternative abiogenesis scenarios have been proposed by scientists in a variety of fields from the 1950s onwards in an attempt to explain how the complex mechanisms of life could have come into existence. These include ...
Haldane's article on abiogenesis in 1929 introduced the "primordial soup theory", which became the foundation for the concept of the chemical origin of life. He established human gene maps for haemophilia and colour blindness on the X chromosome , and codified Haldane's rule on sterility in the heterogametic sex of hybrids in species .
Human life expectancy is a statistical measure of the estimate of the average remaining years of life at a given age. The most commonly used measure is life expectancy at birth (LEB, or in demographic notation e 0, where e x denotes the average life remaining at age x). This can be defined in two ways.
The origin of life from non-living chemistry and geology, or abiogenesis, is a major topic in astrobiology. Even though it is fundamentally an earth-bound concern, and therefore of great geobiological interest, getting at the origin of life necessitates considering what life requires, what, if anything, is special about Earth, what might have ...