An interview with Paul Wignall: How life on earth survived mass extinctions

Wignall jacketAs scientists ponder NASA’s recent announcement about the likelihood of water and the possibility of life, or extinct life on Mars, Paul Wignall, professor of palaeoenvironments at the University of Leeds, explores a calamitous period of environmental crisis in Earth’s own history. Wignall 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. Recently he took the time to answer some questions about his new book, The Worst of Times: How Life on Earth Survived Eighty Million Years of Extinctions.

So why was this the worst of times and what died?

PW: For 80 million years, there was a whole series of mass extinctions; it was the most intense period of catastrophes the world has ever known. These extinctions included the end-Permian mass extinction, the worst disaster of all time. All life on earth was affected, from plankton in the oceans to forests on land. Coral reefs were repeatedly decimated, and land animals, dominated by primitive reptiles and amphibians, lost huge numbers of species.

What was responsible for all of these catastrophes?

PW: There is a giant smoking gun for every one of these mass extinctions: vast fields of lava called flood basalts. The problem is how to link their eruption to extinction. The key is understanding the role of volcanic gas emissions. Some of these gases, such as carbon dioxide, are very familiar to us today, and their climatic effects, especially global warming, seem to have been severe.

Why did these catastrophes stop happening?

PW: This is the $64,000 dollar question at the core of The Worst of Times. It seems to be because of a supercontinent. For 80 million years, all continents were united into a single entity called Pangea. This world was extremely bad at coping with rapid global warming because the usual feedbacks involved in removing gases from the atmosphere were not functioning very well. Since then, Pangea has broken up into the familiar multi-continent world of today, and flood basalt eruptions have not triggered any more mass extinctions.

What were the survivors like?

PW: Very tough and often very successful. It takes a lot to survive the world’s worst disasters, and many of the common plants and animals of today can trace their origin back to this time. For example, mollusks such as clams and snails were around before this worst of times, and their survival marks the start of their dominance in today’s oceans.

Are there any lessons we can apply to modern day environmental worries?

PW: Yes and no. Rapid global warming features in all of the mass extinctions of the past, which should obviously give us cause for concern. On the plus side, we no longer live in a supercontinent world. Flood basalt eruptions of the recent geological past have triggered short-lived phases of warming, but they have not tipped the world over the brink.

Paul Wignall at Otto Fiord at Cape St Andrew.

Paul Wignall conducting field research at Otto Fiord at Cape St Andrew.

Does this have anything to do with the dinosaurs?

PW: Sort of. Dinosaurs first appear towards the end of this series of calamities and to a great extent they owed their success to the elimination of their competitors, which allowed them to flourish and dominate the land for 140 million years. As we know, their reign was brought to an abrupt halt by a giant meteorite strike – a very different catastrophe to the earlier ones.

What would you say to those who want to know how you can claim knowledge of what happened so long ago?

PW: Geologists have a lot of ways to interpret past worlds. The clues lie in rocks, so mass extinction research first requires finding rocks of the right age. Then, once samples have been collected, analysis of fossils tells us the level where the extinctions happened. This level can then be analyzed to find out what the conditions were like. It’s like taking a sample of mud from the bottom of the ocean and then using it reconstruct environmental conditions. However, not everything gets “fossilized” in ocean sediments. For example, it is very hard to work out what past temperatures were like, and ocean acidity levels are even harder to determine. This leaves plenty of scope for debate, and The Worst of Times looks at some of these on-going scientific clashes.

Read chapter 1 here.

Does De-extinction Bring us Closer to a Real Jurassic World? Beth Shapiro Sounds Off

How to Clone a Mammoth, by Beth ShapiroAs we all await the release of Jurassic World this week, (catch the trailer here), the owner of Russia’s vast nature reserve, Pleistocene Park, is awaiting the arrival of an actual woolly mammoth. Pleistocene Park is a major initiative in northern Siberia that includes an attempt to restore the mammoth steppe ecosystem of the late Pleistocene period. The park has been in existence since the 1970s, but given the progress scientists have made this year in sequencing the mammoth genome, one can’t help but wonder if a real life Jurassic World in Siberia is now close at hand. Alex Hannaford reports for The Telegraph, and the takeaway is we shouldn’t get too excited about going on a T-Rex safari anytime soon:

For the last 20 years at least, most scientists have poured scorn on the idea that dinosaurs could be cloned using the method popularised in the first Jurassic Park film — extracting DNA from an insect entombed in resin. A few years ago scientists studying fossils in New Zealand revealed that the bonds that form the backbone of DNA would be entirely degraded — useless — after 6.8 million years. And seeing as dinosaurs last roamed the Earth 65 million years ago, that ruled out any realistic chance of sequencing their genome.

But the wooly mammoth died out far more recently, which makes it quite another story, according to Beth Shapiro, author of How to Clone a Mammoth. She talks to The Telegraph about the more plausible uses of de-extinction technology:

De-extinction, this process of swapping out genomes in existing animals for traits that their ancestors had, but which they could benefit from today, could have other uses, Shapiro says. “Let’s say all of the natural habitat for elephants disappeared. If we could swap those cold-surviving genes [of the mammoth] into elephants, so that we could stick elephants into wild places in Europe or Siberia where elephants used to live, we could use this technology — not to bring mammoths back but to save elephants.”

Shapiro tusk photo

Regardless, de-extinction remains highly controversial, and Shapiro has become a go-to expert on the matter. Carl Zimmer writes in Wall Street Journal, “For anyone who wants a thorough understanding of the technical issues involved in de-extinction, How to Clone a Mammoth should satisfy your curiosity.” During Shapiro’s European tour, she was interviewed about her book for BBC World Service, The Forum and the interview is now available online. Beth was also interviewed for BBC Radio Wales Science Café, as part of a program featuring scientists speaking at Hay Festival. Voice of America aired their interview with Beth recently as well, as did CBC Radio’s national science program Quirks & Quarks.

Shapiro and Kendall

Beth Shapiro and The Forum’s presenter, Bridget Kendall

If you’re looking for eerie similarities between life and art in this case, rest assured they do exist. According to Shapiro, as in real life, “Jurassic Park scientists were only able to recover parts of the dinosaur genome—in the case of the movie, from the mosquito blood that was preserved in amber.” Prospect Magazine’s website has just run an abridged extract from How to Clone a Mammoth where Shapiro elaborates on the real (and not so real) science of Jurassic World. You can also check out the series of original videos by Shapiro on the real life science of de-extinction here.


Mark Witton explains exactly what is in his new book, Pterosaurs

Pterosaurs is meant to provide an interesting read for researchers and diehard enthusiasts, while still being approachable for those who are yet to really acquaint themselves with flying reptiles. If you’re familiar with the Unwin and Wellnhofer books, you know the tone I’ve aimed for. (Those interested in reading a sample of the text will want to download the first chapter from Princeton University Press, and check out an early draft [essentially unchanged in the published text] of Chapter 17.) Pterosaurs is, of course, more up to date than either of these books. Only seven years passing between this book and the last, but the differences are quite pronounced. Despite both Unwin’s and Wellnhofer’s books dating very well, whole groups of pterosaurs have been discovered since their publications (e.g. ‘boreopterids’, chaoyangopterids, wukongopterids, and many more in the case of Wellnhofer’s tome) and ideas of pterosaur lifestyles and habits have changed considerably. It’s of small significance in this field of three modern pterosaur books but, by default, Pterosaurs is the most up to date synthesis on these animals currently available.

Thalassodromeus sethi, a pterosaur with a most unfortunate name, showing a baby Brazilian spinosaur that the food chain works both ways. One of my favourite paintings from Witton (2013).

Pterosaurs is meant to combine the best aspects of preceding pterosaur books into one package, putting Unwin’s terrific introduction to the group together with Wellnhofer’s coverage of all pterosaur species and important fossils. This results in nine chapters covering the broad-strokes of pterosaur research: the history of their discovery, evolutionary origins, osteology, soft-tissues, locomotion (flight and terrestrial locomotion are discussed separately), palaeoecology and extinction. The other 16 chapters focus on specific pterosaur groups, each featuring a history of discovery, distribution maps, overviews of anatomy (including soft-tissues, where known) and discussions of palaeoecology. These latter chapters broadly follow the phylogenetic scheme of Lü et al. (2010) but, because that will not please everyone, alternative taxonomic proposals are mentioned and discussed where relevant (though hopefully not at expense of readability!). Attempts to present different sides to contentious issues are continual throughout the book. As readers will discover, there is still a lot to learn about these animals and it would be foolish to present only a single view as ‘right’ when pterosaur science continues to evolve and change. The drive to give everyone fair hearing resulted in a reference list of over 500 works and, hopefully, this will make the book a useful starting point for students new to pterosaurs and wanting to hit the primary literature. (Incidentally, Lü Junchang needs to take a bow as probably the most prolific modern pterosaur worker, his portion of the citation list dwarfing virtually everyone else’s despite only beginning in the mid-nineties. Way to go, JC!)


Read the complete post over at Mark’s blog:




Natural History, Evolution, Anatomy
Mark P. Witton