Adam Maloof on Earth History

Tell me about your work and how it connects to the environment.

I study Earth history. For example, the Neoproterozoic-Cambrian Era (900-490 million years ago) is a particularly important interval in Earth history because, at the same time that Earth endured radical drift of the continents and a glaciation that sealed the global ocean in ice for millions of years, animals first evolved and quickly became large and diverse. I choose precipitated sedimentary rocks such as limestone as my history books because a single outcrop of limestone may contain physical evidence for the energetics of winds, waves and currents, biological imprints of ecology and evolution, chemical records of the climate system, and magnetic evidence of latitude and geography.

My study group conducts extended field campaigns to map these physical and chemical records into a three-dimensional landscape of ancient environments. My goal is to tell rich stories of Earth history that shed light on the origin of animals and the evolution of Earth’s climate.

I would say that these days climate is front and centre in many academic departments. To date, the emphasis really has been on trying to predict future climate change. However, even as models get more and more sophisticated, model predictions remain highly uncertain. Some of this uncertainty comes from not knowing how sensitive our climate is to various events known by scientists as climate forcings. I think the most valuable piece of information missing in studies of the modern climate system is a deep understanding of Earth’s past to shed light on how Earth has responded to similar forces in the distant past. 

You can make the connection to any field. No one would ever study modern political science without a basic understanding of human history and civilisation, and no one would ever study a modern animal without a basic understanding of evolution. Well, it is the same with the climate and Earth history; the only problem is that you have to study nature and not books to understand Earth history.

Tell me about your first book, The Sheltering Desert by Henno Martin.

Henno Martin is a geologist who before World War II was famous for finding and supplying water to farms in Namibia. During the war he spent a two-year exile in the Namib Desert to avoid being interned by the South Africans for being German. So in 1940 he set out with a pistol, air rifle, two cars and his partner Hermann Korn. What kept them sane during those two years of survival in the desert was curiosity and mental exercise – whether they were making geological maps or discussing Darwinian evolution. The Sheltering Desert is a book about his experiences in the desert.

For me the book demonstrates their deep respect and understanding of nature. When you live outside, you obtain a completely different understanding of what is around you. You observe the sun, moon and stars. You look at animal behaviour and end up seeing them as human. And when you think about humans, you see some characteristics and behaviours that would not be out of place in the wild.

In the book there is a lot of discussion about evolution. Henno is constantly considering how important learning from experience during a single lifetime is compared to Darwin’s chance mutations. I can imagine how steep the learning curve would have been, surviving in the desert for two years, and I can see how Henno would have realised how much knowledge he was obtaining through daily experience and how he would wonder if this knowledge would be passed on to the next generation as a form of evolution. Reading this book made me want to read Darwin’s The Origin of Species.

Martin wrote, ‘For me the most important gain of our life in the Namibia was the experience that the human mind can rise above even the most savage conditions’, which really inspired me.

It is not that what we do out in the field is that adventurous, but sometimes things happen. I have been in a helicopter crash, I have been on a cliff for 24 hours with a bear waiting below me, and when these things happen you slowly realise that it is remarkable how resilient a person can be if you keep your wits about you. That is what Henno and Hermann were going through but in a much more extreme fashion.

I was inspired by seeing how they coped and how they used scientific discussion to get through their experience. I still remember when our helicopter crashed in the Mackenzie Mountains of the Canadian Arctic, we jumped out of the chopper and ran for cover, and the first thing Paul Hoffman, my adviser at the time, did was start discussing the nearest rock outcrop. It was scary and comical at the time, but it was also coping, and it is amazing what you can endure when your mind is preoccupied with curiosity and a yearning to understand the natural world. In the Namib Desert, Henno’s and Hermann’s minds never stopped being active. When they felt dehydrated and weak they still carried on studying their environment, whether it was finding a new way to hunt, observing animal behaviour, or mapping where they were.

You say that reading The Sheltering Desert prompted you to read your next choice, The Origin of Species by Charles Darwin.

Yes. For me (and many others) this book forms the foundation for modern biology. It is all about humans’ concept of themselves. And, considering how long ago it was written, it is surprisingly readable.

Specifically, what Darwin has in mind is a biological analogue of uniformitarianism, which is a theory developed through a combination of James Hutton, John Playfair and Charles Lyell. Charles Lyell was really the one who popularised the idea, and did it in book form. But Hutton, who was a gentleman farmer, made a great observation – he saw that each year part of his farm would erode away. The dirt would be carried by rivers and rain water to the sea. We call it run-off today. Hutton realised that if he went down to the beach he would see sediments that had accumulated as layers and he could measure their thickness. 

And then he had this eureka moment and he realised that when you go to a mountain by the sea there are all these layered rocks that are probably analogous to the layers of sediment he saw forming today. He also realised that the layers probably accumulated at the same rate in the past that they do now, so that when you count these thousands of layers of rock you would realise that Earth is very very old. This idea, that the same processes occurring slowly and steadily today also have been active throughout Earth history, slowly but steadily shaping the landscape, is known as uniformitarianism.

And Darwin used the same principles to describe evolution. In Darwin’s voyage on the Beagle, he observed speciation occurring today –  birds isolated on different islands adapting to their environment and developing new characteristics. So he deduced that slow and steady (uniformitarian) development throughout Earth history (ie, evolution) could explain the myriad animal and plant forms preserved in the fossil record.

A school of thought developed in reaction to uniformitarianism called catastrophism, where people realised that there are occasionally very large events such as a meteorite hitting Earth. In the case of evolution, punctuated equilibrium describes rapid evolutionary development, sometimes in response to sudden environmental change. To me this uniformitarian-catastrophist debate was fascinating, and I sought to observe evidence for both in the geological record. But in my first read of Darwin, one quote in particular stunned me, and continues to inspire much of my work today:

I cannot doubt that all the Silurian trilobites have descended from some one crustacean, which must have lived long before the Silurian age... Consequently, if my theory be true, it is indisputable that before the lowest Silurian strata was deposited, long periods elapsed, as long as, or probably longer than, the whole interval from Silurian to the present day... The case must at present remain inexplicable; and may be truly urged as a valid argument against the views here entertained.

What is so interesting about this quotation is that he recognised that despite all of his work defining and documenting gradual animal evolution, the first animals themselves seem to have appeared very suddenly and with a remarkable degree of initial complexity. You have four billion years of our history without the slightest inkling of an animal and then suddenly nearly all the animal body plans that exist today appear, and gradually evolve. So Darwin asked why did they suddenly appear? What is missing? Is the fossil record incomplete, or is there something very fundamental about evolution that we do not understand?

How does this help you with what you do?

Well his work really inspired me to study the Cambrian era (which he referred to as Silurian).  I can’t help constantly wondering what kind of impact of climate change would have had on animal development and, vice versa, what kind of impact on the environment did early animals have – just like today, with humans having a major impact on the environment.