At the beginning of the Neoproterozoic Era-around one billion years ago-there was no trace of life as we know it on Earth. By the end of the period, however, the first forms of life, such has microbes and cyanobacteria, had begun to crop up in the oceans. And exactly what sparked this important development has kept scientists busy for decades. Indeed, there are various theories about what happened during the Neoproterozoic Era to sow the seeds of complex life forms, and one of them involves glaciers.
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