New research is shedding light on a little understood time in our planet’s history. More than 250 million years ago, when Earth was predominantly one land mass surrounded by water, nearly all life on the planet was killed off. This mass extinction, the most dramatic die-off of animal life to date, marked the transition between two periods on Earth’s geological timeline -- the end of the Permian and the beginning of the Triassic.

The dawn of the Permian period brought with it the advent of the Triassic period, what we know as the beginning of the age of dinosaurs. Scientists have speculated what exactly caused the mass extinction at the end of the Permian period 250 million years ago, but evidence of its origin has eluded them. According to Business Standard, the dominant theory is that a series of volcanic eruptions in present-day Siberia spewed huge volumes of gases into the air that resulted in a global ozone collapse.

According to Nature World News, researchers led by Benjamin Black of the Massachusetts Institute of Technology wanted to test that theory. Using advanced 3-D modeling technology, they predicted the impact that gases released from the Siberian volcanoes, known as the Siberian Traps, would have had on the prehistoric environment.

Their results, published in the journal Geology, show that the effects of these eruptions on Earth’s atmosphere would have been devastating. Researchers noted that the amount of carbon dioxide and sulfur dioxide emitted by the volcanoes could have created very acidic rain. Acid rain would have leached the soil and damaged plants and other vulnerable organisms.

This, combined with drastic changes in ultraviolet radiation and a rise in global temperatures from the release of greenhouse gases, would have been enough to almost completely wipe out life on Earth. According to United Press International, the mass extinction of life at the end of the Permian period, known as the Great Dying, resulted in the death of roughly 90 percent of all marine species and 70 percent of all terrestrial species.

While volcanoes and even rotting vegetation still contribute to acidic precipitation, human activity causes most of today’s acid rain, National Geographic reported. The burning of fossil fuels, mainly coal, and automobiles, are the main factors contributing to acid rain.

Its greatest impact today is on lakes, streams and rivers. Acid rain causes bodies of water to become more acidic, making them toxic to marine life. In an ecosystem where everything is connected, an effect on one system is essentially an effect on all of them.