The breakup of supercontinents over the last 443 million years is responsible for the richness of global marine life, researchers show in a new study. In fact, a "significant component" of marine animal diversity is due to the creation and then separation of just one supercontinent – Pangaea - more than 175 million years ago.
What it tells us: Biologists have wondered for decades why the animal world is so diverse across the planet. They began to hypothesize in the 1970s that plate tectonics causing shifts in the continental crust were probably responsible for the global dispersal of species. But, at the time, they had no way to prove that biodiversity grew when supercontinents split apart.
How they cracked the case: Researchers used global marine fossil data and matched it up against continental configurations and reconstructed paleographic records. As supercontinents split apart, the fossil record shows a much greater richness among various forms of marine life.
- Marine life = bivalves like clams, trilobites — some of the earliest animals with an exoskeleton, extinct marine mollusks known as ammonoids, primitive nautilus and other invertebrate animals
How it works: Animals evolve under pressure, especially from their environment. When a supercontinent breaks up, marine animals connected to each land mass are carried to other parts of the world like passengers on a ship. Species adapt in a multitude of ways to their new environment, contributing to diversity.