Sorry, Doomsday Forecasters, Earth’s Mas…

Sorry, Doomsday Forecasters, Earth’s Mass Extinctions Occur At Random

“Unfortunately, it’s human nature to seek patterns wherever things occur, but in this case, the evidence is far too weak to bet against randomness in any way. It’s important to remember that just because we don’t see evidence for periodic events doesn’t mean they don’t occur, but it’s important to not go chasing after a phenomenon that doesn’t have the evidence supporting its reality. Asteroid and comet strikes may have increased likelihoods at certain times, and there may be a periodic effect for CO2 levels and the carbon crustal cycle, but neither one has any evidence linking them to mass extinctions. When it comes to catastrophic events for the planet, and the species that inhabit it, randomness is as good as it gets.”

We’ve all wondered, at some point, if the asteroid that wiped out the dinosaurs isn’t a phenomenon that might not have been completely at random, but rather caused by a periodic, cosmic occurrence. Could our motion through the galaxy cause asteroidal or cometary impacts to occur more frequently at certain times? Would those times be periodic? And if so, could it make a mass extinction event more likely at certain times? This doesn’t need to be restricted to asteroids, but could be related to periodic geological or climatic changes as well. Fortunately, we know how to analyze this type of data, and to look for patterns in whether these extinction events appear at random or at uniform spacings. In 2013, the best analysis ever of this was undertaken by Fabo Feng and Coryn Bailer-Jones. As they conclude, in their own words: “…the time distribution of mass extinction events is consistent with being randomly distributed in time. There is no need to resort to anything more exotic.”

If you wanted to forecast our natural doomsday, the Universe isn’t going to help you out. Earth’s mass extinctions occur at random, and we’ve got the scientific evidence to back it up!