Extinction domino effect that could annihilate all life on earth

The extinction of plant or animal species due to extreme environmental changes increases the risk of an "extinction domino effect" that could annihilate all life on earth, a new study published Tuesday has found.

The worst-case scenario of "co-extinctions," where an organism dies out because it depends on another doomed species, was based on a study of more than 2,000 virtual earths subjected to a series of catastrophic incidents, including global warming or an asteroid impact.

The study, published Tuesday in Scientific Reports, found such environmental changes could ultimately end all life on earth.

For example, a plant pollinated by a species of bee will eventually die if the bee goes extinct. 

"Or, a cheetah focussing on particular antelope species, or say, koalas that only eat certain types of Eucalyptus [leaves]," the study's co-author, Corey Bradshaw, a professor at Flinders University in South Australia, told dpa. 

Italian researcher Giovanni Strona, the study's lead author, said because all species are connected in a web of life, "even the most tolerant species ultimately succumb to extinction when the less-tolerant species on which they depend disappear." 

The researchers found that in the case of global warming, the combination of intolerance to heat combined with co-extinctions mean that increase of 5 to 6 degrees globally would wipe out most life on the planet. 

"Not taking into account this domino effect gives an unrealistic and exceedingly optimistic perspective about the impact of future climate change," Bradshaw said.