When I was a kid 60 + years ago the teachers told us that winged dynosaurs couldn't fly because they were too heavy and had no feathers. They weren't thinking that the atmospheric pressure was around 100 pounds per square inch--five to ten times what it is today. During ancient times you would have had to saw 3/4 of the wings off your plane to fly 60 miles per hour. Our teachers didn't have any idea why dynosaurs grew to such gigantic size. Recent experiments in Japan with hyperbaric plant growth shed some light on the subject. We now know that Earth has lost 99% of its original atmosphere. This is the last gasp for any intelligent life on the planet.
I had several thousand people read the following two articles which explain a great deal how bilogical structures evolved.
HOW NONCYCLIC PHOTOSYNTHESIS JUMPSTARTED LIFE, HILLARY CLINTON AND EVERYTHING THAT FILLS A NICH.
True plants use carbon dioxide and water (along with nitrogen and phosphorus from the soil) to make organic compounds and produce oxygen as a waste product. When the plant needs to use any of the energy it stored, it uses oxygen to “burn” its fuel, generating water and carbon dioxide as byproducts of that process.
To take advantage of the energy stored in the plants, animals eat the plants directly or eat other animals that do. Like the plants, they use oxygen during metabolism and produce waste water and carbon dioxide. Both plants and animals need additional water for a variety of functions: For example, the transport of nutrients up from the roots is powered by the evaporation of water from the leaves and animals use water to regulate temperature through evaporative cooling and to dispose waste products. A small fraction of the earth’s living things are anaerobic or harvest inorganic chemical energy, and so do not fit into this cycle.
ENERGY CYCLE IN PLANTS
The photon energy: “sunlight” activates electrons, which are removed from the chlorophyll before they can reemit that energy. These “excited” electrons are used to charge a membrane battery, which is used to make the energy transfer compound, adenosine triphosphate (ATP). In the process the energized electrons, having been activated days or even years earlier, lose their energy and are discarded in energy poor carbon dioxide. The ATP is used as a carrier for the electron energy. Every organism faced nutrient poor conditions and so for every 99.9 percent of new life forms that evolved only one-tenth of one percent survived while all the rest are now extinct. --James L. Gould, Carol Grant Gould
It was the unique property of water with two hydrogen atoms each with a positive charge and one oxygen atom with a negative charge referred to as nonpolar molecules that allow weak electro static associations (hydrogen bonds). Their unique geometry allowed the self-repairing, bilayer membrane of the living cell. Modern cells protect themselves from the environment with bilayer membranes to which specific chemical doors and pumps have been added to help control molecular in-and-out traffic.
Hydrogen Cyanide, for example, is readily formed from ammonia and methane and then converted into the nucleotide adenine, which is also the backbone of ATP. –Chemical Evolution and the Origin of Life, By Richard E. Di ckerson; Scientific American, September, 1978
Many meteorites and comets contain abundant inorganically formed organic compounds. Natural selection must have been at work from the very onset, favoring liposomes with the most useful chemistry favoring those with the most useful building blocks and excluding those that might be toxic. At this point in time most organisms were autotrophs—that is, creatures that took energy or energy-rich materials from the nonliving world around them—as apposed to heterotrophs, which eat other organisms (you).
The next step in the evolution of living organisms was the development of cyclic photosynthesis—cyclic because the electron energized by an incoming photon from the sun is quickly returned to the chlorophyll molecule from which it came. Chlorophyll is embedded in a membrane along with the enzymes that steal the activated electron and harvest its energy; that energy is used to charge the membrane, and the electrostatic potential created is later employed to make ATP.
It takes about two photons to charge the membrane; enough to make one ATP, and since photons are free, life must suddenly have been released from dependence on inorganic nutrients synthesis: with photosynthesis! Suddenly there was enough ATP to generate nutrients from simple chemicals like carbon dioxide and ammonia!!! There are still bacteria that employ only cyclic photosynthesis.
There still wasn’t enough ATP available to store large supplies of sugars and starches to give evolution a much needed boost so nature invented the noncyclic process which created eight times more ATP than the cyclic process. In that process the electron energy is boosted in two steps, and so much extra charging and other work is wrung from its energy that eight ATP’s can be made from two activated electrons because the electron is not returned to the chlorophyll but is handed to an energy-storage molecule instead; the missing electron is obtained by splitting water, which generates oxygen as a waste product.
To put it another way, the electron end up in a multipurpose energy compound that can be used directly to power carbon fixation to charge the membrane for subsequent ATP production. The missing electron in the first chlorophyll is replaced with one obtained by splitting water, a process that liberates oxygen.
Most photoautotrophs (all true plants) use the more efficient noncyclic process with the eight-fold increase in energy production.
Because eight times more ATP was being produced by all the plants they were able to create more energy storage in the form of carbon-based, starches and sugars. The noncyclic process not only created more free oxygen it also allowed millions of other life forms to evolve to feed on the extra, eight-fold energy created by this process. This is why we have coal, oil and limestone on Earth plus myriads of other oxygen-breathing animals like Hillary Clinton.
--The Assembly of Cell Membranes by Mark S. Bretscher; Scientific American, October 1985
--The Photosynthetic Membrane by By Kenneth R. Miller Scientific American, October 1979
--Molecular Mechanisms of Photosynthesis by Douglas C Youvan and Barry L. Marrs; Scientific American, June 1984
--Cytochrome C and the Evolution of Energy Metabolism, by Richard E. Dickerson, Scientific American, March 1980 Offprint 146
Me: Captain Hank Kroll, navigator http://www.alaskapublishing.com
WHEN DID EARTH GET A 20.8% OXYGEN-RICH ATMOSPHERE?
It is generally believed that life on Earth probably wouldn’t have developed if the early atmosphere had been oxygen rich. Photosynthesis bacteria were surely not the first living organisms, but the history of life in the period that preceded their appearance is still obscure. What little information can be inferred about early earth is consistent with the idea that the environment was then largely anoxic (without oxygen). One tentative line of evidence rests on the assumption that among organisms living today those that are simplest in structure and in biochemistry are probably the most closely related to the earliest forms of life. Those simplest organisms are bacteria of the clostridal and methanogenic type, and they are all obligate anaerobes.
Somewhat later such bacteria gave rise to the first organisms capable of aerobic photosynthesis, the precursors of modern cynaobacteria. For the anaerobic photosynthetic bacteria the molecular oxygen released by this mutant strain was a toxin, and as a result the aerobic photosynthesizers were able to supplant the anaerobic one in the upper portions of the mat communities. The anerobic species became adapted to the lower parts of the mat, where there is less light but also a lower concentration of oxygen.
The anaerobic nature of bacterial photosynthesis seems to present a paradox: photosynthetic organisms thrive where light is abundant, but such environments are also generally ones having a high concentration of oxygen, which poisons bacterial photosynthesis. These contradictory needs can be explained if it is assumed that anaerobic photosynthesis evolved among primitive bacteria early in the Precambrian, when the atmosphere was essentially anoxic. The photosynthesizers could thus have lived in mat-like communities in shallow water and in full sunlight.
The several groups of photosynthetic bacteria differ from one another in their pigmentation, but they are alike in one important respect: unlike the photosynthesis of cyanobacteria and eukaryotes, all bacterial photosynthesis is a totally anaerobic process. Oxygen is not given off as a byproduct of the reaction, and the photosynthesis cannot proceed in the presence of oxygen. Whereas oxygen appears to be a requirement of green plants for the synthesis of chlorophyll, oxygen inhibits the synthesis of bacteriochlorophylls.
It is argued that oxygen must have been freely available by the time the first eukaryotic cells appeared, probably 1,400 to 1,500 million years ago. Hence, the proliferation of cyanobacteria that released the oxygen must have take place earlier in the Precambrian. How much earlier remains a question. The best available evidence bearing on this issue comes from the study of sedimentary minerals, some of which may have been influenced by the concentration of free oxygen at the time they were deposited. In recent years a number of workers have investigated this possibility, most notably Preston E. Cloud, Jr., of the University of California at Santa Barbara and the U. S. Geologic Survey.
One mineral of significance in this argument is uraninite (UO2), which is found in several deposits that were laid down in Precambrian streambeds. In the presence of oxygen, grains of uraninite are readily oxidized to U3O8 and are thereby dissolved. David E. Grandstaff of Temple University has shown that streambed deposits of the mineral probably could not have accumulated if the concentration of oxygen was greater than about 1 percent. Uraninite-bearing deposits of this type are found in deposits older than about two billion years but not in younger strata, suggesting that the transition in oxygen concentration may have come at about that time.
The most intriguing mineral evidence for the date of the oxygen transition comes from another kind of iron-rich deposit; the banded iron formation. These deposits include some tens of billions of tons of iron in the form of oxides embedded in a silica-rich matrix; they are the world’s chief economic reserves of iron. A major fraction of them was deposited within a comparatively brief period of a few hundred-million years beginning some what earlier than two billion years ago. That would have been a time when the earth was cooling after the planet building phase.
A transition in oxygen concentration could explain the major episode of iron sedimentation through the following hypothetical sequence of events. In a primitive, anoxic ocean, iron existed in the ferrous state (that is, with a valence of +2) and in that form was soluble in seawater. With the development of aerobic photosynthesis small concentrations of oxygen began diffusing into the upper portions of the ocean, where it reacted with the dissolved iron. The iron was thereby converted to the ferric form (with a valence of +3) and as a result hydrous ferric oxides were precipitated and accumulated with silica to form rusty layers on the ocean floor. As the process continued virtually al the dissolved iron in the ocean basins was precipitated: in a matter of a few hundred million years as the world’s oceans rusted. Could this have been a time when our solar system entered an area of space with a salt cloud? Does the Oort cloud and Kippier belt of the Sirius system contain salt?
In my book, Cosmological Ice Ages I propose that our solar system was captured by Sirius binary system at about that time 700-million years ago thereby imparting additional ultraviolet light to earth which would release more oxygen into the atmosphere with increased photosynthesis. It would have taken the power of a White Dwarf star to break through early earth’s thousand-pound per square inch-thick atmosphere to get oxygen producing plants to grow. During the Precambrian the sun didn’t burn nearly as hot as it does today. Any suggestion that our sun is solely responsible for all the biological-deposited layers on earth isn’t taking into consideration the higher atmospheric pressures and the fact that Earth had previously been in an Ice Age for over one billion years.
Fossil stromatolites first became abundant in sediments deposited about 2,300 million years ago, shortly before the major episode of iron-ore deposition. It is therefore possible that the first widespread appearance of stromatolites might mark the origin and the earliest diversification of oxygen-producing cyanobacteria. Even at that early date the cynaobacteria would probably have released oxygen at a high rate, but for several hundred million years the iron dissolved in the oceans would have served as a buffer for the oxygen concentration of the atmosphere, reacting with the gas and precipitating it as ferric oxides almost as quickly as it was generated.
One thing the scientist may have missed here is the fact that iron and dust from space during the Precambrian planet-building phase near our sun’s birthplace in Orion may account for some of the dissolved iron in the oceans. After our sun was captured by the Sirius trinary (multiple star-system) it passed through several oort clouds that may have imparted additional iron and salt to fertilize Earth’s oceans. The salt would have sped up the oxidation of the iron. Scientist aren’t sure where all the salt came from on earth and our capture by the Sirius and Procyon multiple star cluster would explain it.
Sirius B was a six-solar-mass star before it shrunk down into a white dwarf of 1.5 solar masses. That means there was 4.5 solar masses of iron and other material injected into the surrounding oort cloud of Sirius A. In addition Procyon B, currently 10.4 light years away also injected considerable iron into the neighborhood. Of course none of these stellar explosions could have happened while our sun was in the neighborhood otherwise we wouldn’t be here.
Only when our solar system traveled away from its birthplace in Orion and the oceans had been swept free of unoxidized iron and similar material would the concentration of oxygen in the atmosphere have begun to rise toward modern levels.
Much still remains uncertain regarding the evidence from the fossil record. Modern biochemistry from geology and mineralogy make possible a tentative outline for the history of Precambrian life.
Much is also uncertain about the fossil record of human evolution as well. After the mapping of the human genome scientists noticed large segments of human DNA that seemed totally unrelated to the development of a human—that is, until they started to compare these segments with other animals. They experienced the most astounding thing—the shock of a lifetime. Segments of the so-called “junk DNA” were identical to pig, cow, horse and even bacterial DNA. Humans obviously evolved on this planet and are related to most every other animal on the planet including bacteria. Without bacteria we couldn’t digest our food. We carry around billions of bacteria in order to live. We share a symbiotic relationship with most everything on Earth—especially the diatoms which at the major producer of free oxygen.