Scientists have long known that extremely low levels of free-oxygen [< 10-5] atmosphere on early Earth are critical for any viable origin of life model of evolution.
The controversy surrounding the atmospheric concentration of oxygen in the origin of life stems from the laws of organic chemistry.
The autonomous assembly of complex organic molecules has only been observed in an oxygen-free atmosphere.
However, the evidence for an oxygen-free Earth atmosphere has a checkered history.
History of Oxygen-Free Early Earth Theory
Russian biochemist Aleksandr Oparin early in the twentieth century, proposed that early Earth was composed of a reducing stellar atmosphere—an oxygen-free atmosphere. British geneticist John B. S. Haldane expanded on Oparin’s early Earth oxygen-free theory, coining the term “ Primordial soup.”
Riding the then-popular wave, in the 1950s, physical chemist Harold C. Urey promoted the “cosmochemistry” theory—life on Earth arose from stellar gases in an oxygen-free atmosphere. , Urey’s graduate student, performed in the laboratory the infamous Miller-Urey experiment producing amino acids capable of forming proteins in an oxygen-free atmosphere in 1953. Urey’s cosmochemistry theory is more popularly known as abiogenesis – life arising from simple organic molecules.
An oxygen-free atmosphere is a reducing atmosphere. By contrast, a free-oxygen atmosphere produces an oxidizing atmosphere. An oxidizing atmosphere prevents the assembling of organic molecules from stellar reducing gases consisting primarily of methane (CH4) and ammonia (NH3).
To account for rising in free-oxygen concentration on the Earth, the evolution industry developed the Great Oxygen Event (GOE) theory which has also been variably called the Oxygen Catastrophe, or the Oxygen Crisis. Free oxygen, according to this theory, entered the atmosphere after the spontaneous generation of cyanobacteria on Earth.
In the words of the British Broadcasting Company (BBC), “Cyanobacteria, which appeared about 200 million years (sic) before the GOE, began producing oxygen by photosynthesis. Before the GOE, any free oxygen they produced was chemically captured by dissolved iron or organic matter… After the GOE, the excess free oxygen started to accumulate in the atmosphere.”
Problems with Oxygen-Free Early Earth Theory
Scientists, however, have not reached a consensus on the GOE. “The question of when oxygenic photosynthesis evolved,” according to WIKIPEDIA, “continues to engender debate and research.”
Little wonder that GOE theory engenders debate. One reason is that the spontaneous generation of cyanobacteria (abiogenesis) from chemicals contradicts the Omne vivum ex vivo (all life from life) natural law founded by the “father of microbiology,” Louis Pasteur.
The importance of Pasteur’s findings is even recognized by the ever-colorful atheist evolution advocate, Richard Dawkins. In the book The Greatest Show on Earth, Dawkins writes: “Never will the doctrine of spontaneous generation recover from the mortal blow struck by this [Pasteur’s] simple experiment.”
The spontaneous origin of complex photosynthetic reactions violates the second law of thermodynamics is another reason. The complex photosynthetic reaction is continuous and organized in which atmospheric free-oxygen is produced from oxygen in the form of water (H2O) and carbon dioxide (CO2). Carbon dioxide is now infamously known as the “greenhouse gas.” Photosynthesis has never been experimentally produced de novo−from the beginning.
A third reason stems from the discovery that the cyanobacterium is a cytochrome C oxidase-dependent microbe. The purpose of Cytochrome C is to convert free oxygen (O2) into water (H20). Unless biological evolution was somehow armed with a purposeful foreknowledge that a free-oxygen atmosphere would develop in the future, the presence of an enzyme to metabolize oxygen undermines any recognized theory of natural selection.
History of Early Earth Oxygen-Free Theory
One of the first to throw the wrench into the GOE theory was geologist Harrison Brown of the University of Chicago in the 1960s, noting that stellar atmosphere vanished or never existed on Earth.
By the 1970s, Philip Abelson of the Carnegie Institution gave a simple Q&A –
“What is the evidence for a primitive methane-ammonia atmosphere on Earth? The answer is that there is no evidence for it, but much against it.”
Later in the 1970s, Canadian geologists Erich Dimroth and Michael Kimberly issued the following finding –
“In general, we find no evidence in the sedimentary distributions of carbon, sulfur, uranium, or iron that an oxygen-free atmosphere has existed at any time during the span of geological history recorded in well-preserved sedimentary rocks.”
Belgium Biochemist, Marcel Florkin, joined Dimroth and Kimberly in 1975, noting that “the concept of a reducing primitive atmosphere has been abandoned,” and the Miller–Urey experiment is “not now considered geologically adequate.”
Even molecular biologists Sidney Fox and Klaus Dose, joined the discussion in 1977, declaring –
“The inference that Miller’s synthesis does not have a geological relevance has become increasingly widespread.”
In 1982, British geologists Harry Clemmey and Nick Badham, after examining the evidence from the rocks, noted –
“From the time of the earliest dated rocks at 3.7 billion years, Earth had an oxygenic atmosphere.”
By 1995, Jon Cohen, senior editor for Science, the flagship journal of the American Association for the Advancement of Science (AAAS) explains –
“The early atmosphere looked nothing like the Miller–Urey simulation.”
Oxygen-free atmosphere represents a philosophy, not scientific evidence. With the evidence too big to ignore, in 1998, Richard Monastersky, writing for National Geographic, finally broadcast –
“Many scientists now suspect that the early atmosphere was very different from what Miller first supposed.”
Scientific Evidence for Early Earth Free-Oxygen Theory
An international research team led by Sean Crowe, of the University of Southern Denmark, in September published in the journal Nature a paper re-establishing the presence of oxygen in the atmosphere on early Earth. According to the team representing the nations of Denmark, South Africa, and Germany, early Earth’s oxygen exceeded 30 times beyond the critical concentration of < 10-5. Earth was far from an oxygen-free atmosphere.
The researchers studied the ratios of different types, or isotopes, of chromium atoms that were present in the rock drilled from 1,000 meters underground in South Africa.
Biogeologist Roger Buick of the University of Washington in Seattle in an interview with The Scientist noted that the new evidence –
“adds greater complexity to our picture of how and when the Earth got its oxygen. It suggests that oxygenic photosynthesis, the ultimate source of most oxygen (sic), evolved long before the Great Oxidation Event.”
The study tips the evidence against the once popular GOE theory along with the hope of a cohesive abiogenesis theory for the origin of life on Earth. Evolutionary scientists are now shifting the focus for the origin of life exploration to the cosmos.
As the staff reporter for Nature World News dismissively sneers –
“We might have to take a second look at the evolution of life on earth.”
Since Charles Darwin’s publication of The Origin of Species, the emerging scientific evidence has undermined Darwin’s theory (Darwinism), the more popular neo-Darwinism theory, and now the Great Oxygen Event theory.
Genesis
The Genesis account written by Moses, however, continues to be compatible with scientific evidence. The Nobel Prize-winning discover of the DNA molecule, Francis Crick, in the book Life Itself, conceded –
“An honest man, armed with all the knowledge available to us now; could only state that in some sense, the origin of life appears at the moment to be almost a miracle,”
Evidence from the origin of life research to validate the theory of evolution scientifically still remains speculative.
Click to study further evolutionary perspectives on the origin of life and other crucial Evolution and Science categories.
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Links
- Glossary defines terms associated with explaining the theory of biological evolution.
- Understanding Evolution is a journey that showcases how different investigative approaches play a pivotal role in enriching our understanding of the process, leading to diverse conclusions.
- Studying Evolution delves into the terms species and natural selection and how they have changed since The Origin of Species was published in 1859.
- What is Science investigates Charles Darwin’s approach to science and how the principles of modern science are used for different investigative purposes.
- The Evolution and Science category features articles studying how the intersection of evolution and science influences the current understanding of evolution.
- The Theory and Consensus category features articles examining how scientific findings are influencing the scientific consensus on the essential tenets of evolution, including Natural Selection.
