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 period, part of the Paleozoic era, produced the most intense burst of evolution ever known. The Cambrian Explosion saw an incredible diversity of life emerge, including many major animal groups alive today.he Cambrian period, part of the Paleozoic era, produced the most intense burst of evolution ever known. The Cambrian Explosion saw an incredible diversity of life emerge, including many major animal groups alive today.