Podcast: Play in new window
BOB HIRSHON (host):
Cambrian carnivores. I’m Bob Hirshon and this is Science Update.
When you think of marine carnivores, killer whales and sharks probably spring to mind. But they didn’t exist 500 million years ago during the Cambrian period. Instead, tiny carnivorous worms began to rule the oceans, bolstered by rising oxygen levels. This according to Erik Sperling of Harvard and Lisa Levin of the Scripps Institution of Oceanography. Their research team found that areas of the ocean with low oxygen levels support few of these marine predators.
LISA LEVIN (Scripps Institution of Oceanography):
Because carnivory requires a lot of oxygen. The carnivore has move quickly to catch its prey and also because digesting protein seems to take a lot of oxygen.
The researchers think the rise of carnivores drove the evolution of a dazzling array of predator-foiling adaptations in prey species, during the Cambrian explosion. And these innovations are still reflected in the diversity of animal life we see today. I’m Bob Hirshon, for AAAS, the science society.