Saturday, October 10, 2015

Paul B. Wignall's "The Worst of Times"

Paul B. Wignall is professor of palaeoenvironments at the University of Leeds. He has been investigating mass extinctions for more than twenty-five years, a scientific quest that has taken him to dozens of countries around the world. The coauthor of Mass Extinctions and Their Aftermath, he lives in Leeds.

Wignall applied the “Page 99 Test” to his latest book, The Worst of Times: How Life on Earth Survived Eighty Million Years of Extinctions, and reported the following:
The Worst of Times is all about a series of mass extinctions that began to afflict Earth around 260 million years ago, and the book draws on the latest scientific ideas about these disasters. Amongst these natural catastrophes there was the end-Permian mass extinction, the greatest mass dying of all time, and page 99 finds me discussing what happened immediately afterwards. For a long time this interval puzzled geologists because, rather than recover from the extinction, life on Earth took a long time to get back on its feet, many millions of years in fact. In the past few years new evidence has emerged to explain this. It appears that the world was incredibly hot at this time.

Global warming features in all the crises discussed in The Worst of Times and after the end-Permian crisis the temperature rise continued to unheard of extremes. The consequences for life were dire: the tropics became virtually devoid of plants and animals. So, on page 99 I relate how a Chinese research student of mine first discovered evidence of this and how we came to interpret it:
Sun Yadong was the first to notice that something was amiss with fish….. While picking conodonts for his temperature study, he noticed that there were no fish bones and teeth….. Searching the published literature on Early Triassic fish, we found that although they were abundant in high latitudes, very few were found in the tropics. We surmised that the tropics were simply too hot at this time for fish to survive. In contrast, at higher latitudes, where temperatures were cooler everything was fine….
This was a time when the higher latitudes were havens of diversity whilst in the equatorial regions it was like a furnace – the phrase out of the frying pan and into the fire comes to mind. Very gradually things cooled down and life migrated back to lower latitudes and all was well for millions of years. But then, the next crisis struck, and temperatures once again began to climb.

Global warming and mass death sound like rather disturbing themes, given modern day climate trends, but by the end of the book I provide a reassuring note: we’re not living in the worst of all possible worlds like the poor old Triassic fish, if anything our modern, resilient planet is one of the best of worlds.
Learn more about The Worst of Times at the Princeton University Press website.

--Marshal Zeringue