‘Darwin’s Dilemma’ May Finally Have Been Solved
Though the theory of evolution has long been accepted as scientific fact, scientists have always had trouble reconciling Darwin’s notion of gradual evolution by natural selection with a sudden explosion of new species around 530 million years ago.
Now a University of Texas geologist believes he may finally have an explanation for what some refer to as “Darwin’s dilemma”: a major shift in the continents, which created ideal conditions for complex new life forms to evolve.
“At the boundary between the Precambrian and Cambrian periods, something big happened tectonically that triggered the spreading of shallow ocean water across the continents, which is clearly tied in time and space to the sudden explosion of multicellular, hard-shelled life on the planet,” Dr. Ian Dalziel, a research professor at the university’s Institute for Geophysics and a professor in the department of geological sciences, said in a written statement.
The tectonic shift likely opened up a gateway between the ancient continents of Laurentia (modern-day North America) and Gondwanaland (see image below), according to Dalziel. Water displaced by the shift flooded land areas, creating an ideal environment for new species to flourish. The shift also would have dredged —> Read More Here