What event might have changed the ecosystem very quickly?

What time does normal church end on Sunday? What goes putt putt putt putt putt? How many farts in a day the world record? How To Lose Weight? What does it mean when you dream of your child getting shot? Is there such thing as a god cousin? What Bible verses begin with the letter F? How long does it take mail to come from California to Alabama? What walks on four legs in the morning two legs in the afternoon and three legs at night? What is nine months before May? If you have a choice of what you are going to hit in a crash hit the object? Which of these items did the unites states export in the late 19th century? What is the difference between a Southern Baptist and a Missionary Baptist? Where is telephone country code 79? Where is telephone country code 44 7700? How many times do you have to walk around a 5 acre perimeter to walk 1 mile? What would a 100 pound person weigh on Halley's Comet? How many times has mothers day fallen on May 10th since 1955? How many loaves of garlic bread does it take to serve 100 people? What tobacco products does dollar general sell?

What event might have changed the ecosystem very quickly?