What is shown and what not is shown reveals alot about the bias in geologic studies. The start of the earth is depicted in a dusty solar system with the next two billion years are skipped over. There is no depictions of the Earth cooling down or formation of terra firma or the oceans. Instead life is shown starting in a pre-existent sea. This "out of choas" resembles the biblical Judeo-Christian understanding of the early cosmos. Land is not shown on the time spiral until the Cambrian Period, the time period when the first basic microbes began living on dry land. A second major bias demonstrates how geology has abandoned the oceans except for paleogeology. The further the time scale goes the smaller the ocean gets. Also, the time scale does not show when the great marine animals like giant whales and large sharks evolved.
While not a bad learning tool, the geologic time spiral does demonstrate biases in geology.