Professor of Palaeobiology, Department of Earth Sciences.

What is your research area?
My main interest is the history of life in deep time – three-and-a-half billion years ago, right at the beginning of the fossil record.

You’ve been working in the Scottish Highlands - what’s so special about them?
When you go to the northwest corner of Scotland, you enter a very ancient landscape. Many of the mountains on the far west are at least a thousand million years old. A waxy, quite hard material called calcium phosphate, like in your teeth, formed on the lake floor and, like amber, it entombed all the organisms that were inside it.

What did you find there?
When we sectioned the phosphate and looked at it under our clever modern microscopes, we saw all sorts of things that had very complicated outer sculptures. This really grabbed the news. Only algae and higher plants have these complicated outer walls. Bacteria, the most primitive and simple things around, do not and we’re now trying to work out how the bacteria evolved into much more complicated things like the algae, leading to the fungi, and also to the animals. The fossils we found show that this transition from very simple cells to algal cells had taken place at least a billion years ago and they were already successfully colonising the land, so the land surface would have been going a bit green-like, like you see on a tombstone or a college wall these days.

Was this a lot earlier than previously thought?
Yes, it’s as much as 500 million years earlier than any previous evidence. It was a classic example - and I’m embarrassed about this - of a mofaotyof fossil. Everybody in my field is after a mofaotyof, which stands for “my oldest fossils are older than your oldest fossils”. I’ve always been interested in old things – I’m ageist if you like – but that’s what the newspapers publish.

Palaeontology is an old discipline – is it still important?
Palaeontology has the best questions. It’s all about perspective. How did life begin? What does the future hold? Palaeontology shows us how tenuously beautiful our existence is. Most of what I have to say is relevant to looking for life on other planets, so I’d really call myself an astrobiologist, looking at life in the universe from a very large perspective. When our lives are so short, it’s quite nice to have this vicarious experience of the hugeness of the system.