What Was It Like When Oxygen Appeared And Almost Murdered All Life On Earth?
“This might be a simple biological scenario, but its results are nearly universal. In the presence of virtually no competitors or predators, and given practically unlimited resources, a living population will grow at an exponential rate. It will consume the available resources, produce whatever metabolism products it produces, and then reproduce in greater-than-replacement-level numbers.
The next generation will then consume more, produce more of its metabolites, and reproduce even greater numbers. So long as resources are freely available, this process will continue. Until, that it, the metabolic processes it has been undergoing build up to a critical level where it poisons its environment. If this sounds like what the yeast did — or what modern humans are doing with CO2 — you’ve put the pieces together correctly. Organisms, if left unchecked, will poison their habitat with the waste products of their own success.”
Approximately 2.5 billion years ago (but maybe more), a key development occurred in life on Earth: some unicellular creatures that were capable of photosynthesis began producing oxygen as an end-product of their metabolic processes. For hundreds of millions of years, these early cyanobacteria succeeded tremendously, but their success had a by-product: the oxygen poisoned the other organisms around them, as well as the environment as a whole. In short order, Earth was transformed into a giant snowball, leading to perhaps the greatest mass extinction in history: the Huronian Glaciation.