Textbooks frequently make statements like “several billion years ago the primitive earth had a reducing atmosphere.” What does that mean? Instead of containing large amounts of free oxygen as our present atmosphere does, it supposedly contained large amounts of hydrogen, methane, ammonia and other gases. This type of atmosphere would kill most everything that lives today.
What is the basis for such statements in the books? The idea first caught on not because of observation, but because it was essential in the evolution model. If non-living chemicals eventually get together to form living cells by chance naturalistic processes, an oxygen-free environment would be necessary since the very first steps of this process could not take place with free oxygen in the atmosphere. Thus, scientists who had already rejected a supernatural explanation of the origin of life and were firmly convinced that life evolved accidentally were forced to believe that the early earth had an entirely different type of atmosphere than today. So the idea of a reducing atmosphere started as an assumption based on the assumption of evolution.
Is there evidence to substantiate this belief? It seemed like it when a graduate student discovered a layer of alternating red and black bands of iron. The red bands of iron had evidently been formed in an environment containing free oxygen and the black bands formed without it (under the so-called “reducing atmosphere”). Here was “proof” at least for the time period when the earth began to have a change in its atmosphere. Biologists were enthusiastic about the discovery, and the statement became even more entrenched as fact.
Unfortunately for evolutionary biologists, below this banded iron formation was another massive layer of rock which was rich in red (oxidized) iron. This shows conclusively that the atmosphere had contained much free oxygen prior to the deposition of the banded beds. Subsequently, other arguments were suggested to substantiate the claim that the “primitive” earth atmosphere had little or no free oxygen. These arguments are carefully evaluated and exploded by two very respected geologists, Clemmey and Badham, in an article appearing in the March 1982 issue of Geology entitle “Oxygen in the Precambrian Atmosphere: An Evaluation of the Geological Evidence.” After much detailed research, they concluded that from the time of the earliest dated rocks, the earth had an atmosphere with plenty of breathable oxygen. Evolutionists must look for other ways to explain how life originated, and indeed many are desperately looking to do just that.