Historically, Poland has been part of the barrier against the steppe invassions, first the Mongols, then the Russians themselves. From that point of view, it would be central Europe, as the steppe peoples would be eastern Europe. Poles often lived within the HRE, which would place them squarely in the Mittel-europa.
The Cambrian Explosion refers to the metaphorical explosion of life that began 542 million years ago and lasted for roughly 40 million years. This lesson will cover the events that occurred during this time period.
The Cambrian Explosion and the Fifth Day of Creation. The relationship between the Great Unconformity and the Cambrian explosion also explains why God waited until the fifth creation day, after the emergence of the continents (day three), to create animals in the seas. Complex, advanced animal life in the sea could not exist until continents formed.