Lab 8: Darwin's Dilemma

The Burgess Shale is a fossil bed in the Canadian Rockies which contains one of the largest collection of fossils in the world, is known for having numerous soft-body fossils, and is one of the oldest at 505 million years old. This fossil collection gave science an unprecedented look into life in the Cambrian era, where macro-organisms first became prevalent on Earth and set the stage for later evolution into the creatures we know today.

The Cambrian Period is where large animals first took over the Earth, and it was an explosion of new types of life that had never before been seen. Where Pre-Cambrian biota was largely bacteria and some smaller hard-shelled creatures, the Cambrian was lush with many different types of creatures that we today would consider beyond bizarre.

Hallucigenia: A creature so strange it was first reconstructed upside down. There really is no modern analog to this strange Cambrian creature.

Charles Darwin studied the Cambrian Era as an undergrad at Cambridge in Whales, where the first Cambrian fossils were excavated. Throughout the crafting of his Theory of Evolution, Darwin acknowledged that the Cambrian Era posed particular challenges that had to be explained for this Theory to work properly. At the beginning of the Cambrian, there was an explosion of new life in a relatively short period, one that seems to be too short for evolution to work, and the extreme diversity of life cannot currently be accounted for using the Theory of Evolution. According to Darwin, life starts with a small number of phyla, and then diversifies over millions of years. But, in the Cambrian Explosion, the Earth went from a few crab-like creatures and bacteria to having an extremely diverse range of creatures with no real obvious explanation.  In the Prologue of Origin of the Species, Darwin admits that if there were to be a new discovery in paleontology to dispute his theory it would be from the Cambrian period, and that the diversity of life in the Cambrian would be a valid rebuttal of his ideas.

The Burgess Shale continues to pour a wealth of information into the scientific community, forcing us to constantly look and adjust our worldview about the origins of life on Earth and how we came to be.