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The environment
Published in Francesco E. Marino, Human Fatigue, 2019
Regardless of the terminology used, a greater understanding of this particular problem requires consideration of how life on Earth began. Although there is no particular consensus about how life took hold, there is general consensus that early life was subjected to a hot environment (Van Kranendonk et al. 2018). In the 1920s, Oparin and Haldane (Miller et al. 1997) independently postulated that life on Earth began in a primordial soup. They suggested that the Earth’s atmosphere was composed of certain elements, such as nitrogen, ammonia, methane and hydrogen. The addition of heat produced chemical reactions which eventually gave rise to molecules making their way to a water environment and creating a primordial soup largely composed of amino acids as the building blocks of life (Miller 1953). The key ingredient was heat, which assisted in the establishment of those building blocks. A reasonable conclusion would also be that primitive organisms would have a need to control their internal temperature since chemical reactions are necessary for metabolic function. If we also accept that organisms, regardless of how primitive they might be, were able to perform metabolic functions, they would also then be able to reproduce and move to accommodate their needs. A fundamental point in the evolution of organismic function is the ability to graduate from unicellular to multicellular organisms (Schopf 1978).
Origins of Life
Published in Jim Lynch, What Is Life and How Might It Be Sustained?, 2023
Most texts on the origin of life have discussed the Miller-Urey experiments with the same conclusions. One such text published in 2005 by Robert Hazen Genesis. The Scientific Quest for Life’s Origin approaches gives his perspective as a geophysicist and astrobiologist at the Carnegie Institute in Washington, DC. He rejects the ‘primordial soup’ concept in the Miller-Urey experiments as irrelevant because the soup was too dilute and had too many molecular species which could not contribute to life. He points out that a mixture of elements is found near deep-ocean vents at crushing pressures and high temperatures. Life might have started in such a place, nourished by the mineralised organics, and energised by the geochemical forces on the surface of the earth, ocean waves, and lapping rocky shores. He discusses the relevance of laboratory and field observations but indicates that natural processes exist beyond what we now know or what we can comprehend. The central theme is emergence – processes by which more complex systems arise from simpler systems, often unpredictably. This is the opposite of reductionism where any phenomenon can be explained by understanding the parts of that system. For example, orderly arrangement of molecules can appear simultaneously. Such emergent phenomena are common in everyday experience and sometimes require an energy input. Life on earth arose 46 million years ago. The question is posed of where organic compounds came from to start life and why is life chiral (handed) where mixtures of molecules rotate to the left or right. Even though God said (Genesis 1:20), ‘Let the waters bring forth swarms of living creatures’, such processes in life must be subject to the laws of chemistry and physics. Life may be organised as a chemical consequence given the appropriate environment and time, ideas which should be able to be tested by experiment. One of the consequences of interaction among carbon-based molecules is to assemble life’s membranes, proteins, and genetic molecules on rocks and minerals. Many of Hazen’s ideas are stimulated by discussion with Gunter Wachtershauser who was a chemist and patent lawyer and a friend of the philosopher Karl Popper who said that theories to be theories at all in the scientific sense must make testable predictions that have the potential to be proved false by empirical test. If predictions are precise, the more believable they are to scrutiny. If the ‘primordial soup’ concept of life is rejected, there are three other plausible assumptions: The first life form made its own molecules as autotrophs, building its own molecular building blocks from scratch.The first life form relied on the chemical energy of minerals, not the sun, and these are relatively simple like modern cellular processes.Metabolism came first. This does not require encapsulation and membranes and excludes life beginning with a self-replicating model like RNA.
A New Field in Mind: A History of Interdisciplinarity in the Early Brain Sciences
Published in Journal of the History of the Neurosciences, 2023
Stahnisch takes us on a journey beginning in the vaunted university and extra-university clinics and houses where the primordial soup of brain science formed into many major neurologic and neuroscientific discoveries (many of which are eponymous) of the late-nineteenth and early-twentieth centuries. He takes us to the battlefield hospitals of World War I, to the competing Kaiser Wilhelm Institutes for brain research in Berlin and Munich, to Breslau and Vienna, and then to North America. He provides insight on the links between Europe and the Montreal Neurological Institute and Nova Scotia, to Columbia and other institutes in the United States. He wants us to accept the idea that neuroscience started in Central Europe and was transferred to North America through immigrants or through American or Canadian neuroscientists who visited Europe especially in the Weimar German period, and he makes a strong case for this motif throughout the book. At some points, one wonders if there is too much analysis of the tragic fates and tribulations of neuroscientist immigrants that is not directly linked to the foundation of neuroscience.