Having back-up plans and built-in redundancy features can save lives, whether it's emergency flares in the trunk of the car or warning lights and alarms in the cockpit of an airplane. For Earth, failures in redundancy can lead to catastrophe.
In nature, multiple species compete for the same resources, something called ecological redundancy. For example, several species of sharks may feed on the same prey fish. If one species disappeared, the other sharks would take up the slack on chowing down on the extra fish – keeping the system in balance. But if multiple species of shark go extinct, a situation that is currently playing out, the system can veer toward collapse.
For the first time researchers have made a direct connection between loss of redundancy and ecosystem collapse. Their work, published recently in the journal Geology, shows that during extinction events in the Permian and Triassic periods, the Earth's ancient oceans lost critical back-up species.
The research holds a dire warning about humans activities in the oceans and points out the importance of preserving whole ecosystems, not just individual species.