Looking to the Past to see the Future
By Kenneth Carpenter
“Those who cannot remember the past are condemned to repeat it.” — George Santayana (1905)
As
I write this, the world is struggling with the COVID-19 pandemic and it will remain a major event in our lives for many years. But in a few decades it will become history and be largely forgotten just like previous pandemics: Plague of Galen, 165–180 AD, ~5 million dead; Plague of Justinian, 541–542 AD, ~25 million dead; Black Death, 1346–1353, 75–200 million dead; cholera pandemic 1852– 1860, 1 million dead; influenza pandemic of 1889–1890, 1 million dead. As bad as these human pandemics are, some have been worse among animals. The fungal disease chytridiomycosis, has globally caused mass die-offs of frogs, toads, and salamanders over the past 50 years. Although not yet a pandemic, another fungal disease called white-nose syndrome has killed millions of bats in the North America since its discovery in 2006, but for unknown reasons is not fatal for bats in Europe and Asia. Even insects are not immune. Foulbrood is a lethal disease that has decimated honeybees around the world. Not surprisingly, disease has been suggested as a cause for extinctions in the geological past, including the dinosaurs 66 million years ago and ice-age mammals 13,000 years ago. But the evidence for extinctionby-disease is very weak, not least of which because there are no mass death sites representing the last individuals (the bones at Dinosaur National Monument were deposited 84 million years before the extinction of all dinosaurs). So if not disease, then what killed the dinosaurs and what is that to us?
58
UTAHSTATE I FALL 2020
Extinction events viewed through the coarse filter of geologic time give the false impression that one day everything was normal and the next day it wasn’t. The extinction of the dinosaurs is commonly portrayed as everything suddenly changing when an asteroid crashed into the Earth 66 million years ago. Talk about having a bad day! The reality is that some dinosaur species are absent in strata representing tens of thousands to hundreds of thousands of years before the impact. Yet for the convenience of discussion the dinosaur extinction is portrayed as occurring all at once. Extinctions taking thousands of years suggest to me environmental change, and the great driver of that is climatic change. There is much talk these days about global warming and the catastrophic effect this will have on the Earth. As a paleontologist, I am not stressed about this change because the Earth has frequently been much warmer than today. Around 56 million years ago during what is called the Eocene, global temperatures were on average 40+ degrees Fahrenheit warmer than today, with palm trees and crocodiles living north of the Arctic Circle indicating that there was no ice at either pole (sorry Virginia, there was no Santa Claus). Granted,
Paleontologist Kenneth Carpenter’s career centers on examining the past for clues about life. Photo by John DeVilbiss.
