Scientific "Beginning" of Life
28 Apr '07 05:293 editsThis may have been posted some time ago, but I thought I might share it nonetheless...I only learned about this recently, so if it is considered common knowledge, ignore me... 😛
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http://www.tufts.edu/as/wright_center/cosmic_evolution/docs/text/text_chem_5.html
"Appreciating contemporary life is one thing, but understanding how it might have arisen from nonliving matter billons of years ago is quite another. Can we be sure that the basic ingredients for life were present, or would have naturally emerged, on primordial Earth? Furthermore, is it likely that those nonliving building blocks could have fashioned a simple living cell given the harsh conditions on our planet billions of years ago? These questions can best be studied in the laboratory, for the atmosphere and surface of today’s Earth differ greatly from those of the early Earth. Results of modern chemical experiments that mimic the geophysical environment on our young planet imply affirmative answers to these questions.
First, imagine again the setting on primeval Earth nearly 4 billion years ago. Physics had done its job to form the planet, and chemistry was in high gear, but biology had yet to begin. As noted in the previous PLANETARY EPOCH, terrestrial gases interacted with one another, as well as with energy, thereby synthesizing bigger molecules. Nothing magical attends this rise in complexity, provided the environmental conditions weren’t overly adverse and the strength of energy reasonable. Chemistry in action can naturally yield the building blocks of life.
With a test-tube-like contraption capable of holding water and some gase ... laboratory gear can be built to simulate Earth’s early ocean and atmosphere. The gases—usually a mixture of ammonia (NH3), methane (CH4), hydrogen (H), and sometimes carbon dioxide (CO2)—are meant to match the composition of the secondary atmosphere. Though toxic to present-day life, some blend of this gas was apparently just right for the origin of life.
After several days of energizing the gases, a thick, reddish-brown, soupy material collects in the trap at the bottom of the apparatus. Chemical analyses show this slimy product—called “gunk” by some, “pond scum” by others—to contain molecules indeed more complex than the initial reactants at the start of the test. Be assured, no worms or maggots crawl out of this primordial soup—not yet anyway. Nor has a simple cell, or even a single strand of DNA, been made under test-tube conditions. But many of the molecular products that are made are among the known precursors of life. They include several of the amino acids and nucleotide bases comprising the building blocks of all modern life. Chemicals such as formaldehyde (H2CO) are also produced, as well as other molecules (e.g., hydrogen cyanide, HCN, and formic acid, H2CO2) that are known to be among the basic ingredients of life as we know it."
So, what do you think?
Edit -- The title of this thread was probably misleading...from what I am describing above, you probably know I meant the beginning of the organic molecules on which life begins...
__________________________________________________________________
http://www.tufts.edu/as/wright_center/cosmic_evolution/docs/text/text_chem_5.html
"Appreciating contemporary life is one thing, but understanding how it might have arisen from nonliving matter billons of years ago is quite another. Can we be sure that the basic ingredients for life were present, or would have naturally emerged, on primordial Earth? Furthermore, is it likely that those nonliving building blocks could have fashioned a simple living cell given the harsh conditions on our planet billions of years ago? These questions can best be studied in the laboratory, for the atmosphere and surface of today’s Earth differ greatly from those of the early Earth. Results of modern chemical experiments that mimic the geophysical environment on our young planet imply affirmative answers to these questions.
First, imagine again the setting on primeval Earth nearly 4 billion years ago. Physics had done its job to form the planet, and chemistry was in high gear, but biology had yet to begin. As noted in the previous PLANETARY EPOCH, terrestrial gases interacted with one another, as well as with energy, thereby synthesizing bigger molecules. Nothing magical attends this rise in complexity, provided the environmental conditions weren’t overly adverse and the strength of energy reasonable. Chemistry in action can naturally yield the building blocks of life.
With a test-tube-like contraption capable of holding water and some gase ... laboratory gear can be built to simulate Earth’s early ocean and atmosphere. The gases—usually a mixture of ammonia (NH3), methane (CH4), hydrogen (H), and sometimes carbon dioxide (CO2)—are meant to match the composition of the secondary atmosphere. Though toxic to present-day life, some blend of this gas was apparently just right for the origin of life.
After several days of energizing the gases, a thick, reddish-brown, soupy material collects in the trap at the bottom of the apparatus. Chemical analyses show this slimy product—called “gunk” by some, “pond scum” by others—to contain molecules indeed more complex than the initial reactants at the start of the test. Be assured, no worms or maggots crawl out of this primordial soup—not yet anyway. Nor has a simple cell, or even a single strand of DNA, been made under test-tube conditions. But many of the molecular products that are made are among the known precursors of life. They include several of the amino acids and nucleotide bases comprising the building blocks of all modern life. Chemicals such as formaldehyde (H2CO) are also produced, as well as other molecules (e.g., hydrogen cyanide, HCN, and formic acid, H2CO2) that are known to be among the basic ingredients of life as we know it."
So, what do you think?
Edit -- The title of this thread was probably misleading...from what I am describing above, you probably know I meant the beginning of the organic molecules on which life begins...
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