If humans disappeared from the face of the Earth, letting evolution run its course, what would animals look like in 50 million years? That was the premise of the book After Man: A Zoology of the Future, published in 1981 by paleontologist Dougal Dixon. Last month, Breakdown Press published a new edition of the book.

The mythological-looking creatures illustrated in the book seem to come out of a Tim Burton movie. There’s the rabbuck, a rabbit-like animal that has grown the size of a deer because it lives where there are no predators. Then, there’s the reedstilt — also called Harundopes virgatus — with a long, beaky snout and razor thin legs to snatch fish out of the water. And mountainous regions will be inhabited by the groath — also called Hebecephalus montanus — whose females have a pyramid-shaped horn on their heads to defend their young. Dixon clearly let his imagination ran wild, but also took the rules of evolution and adaptation into consideration when envisioning these new species.

When it came out, After Man was often portrayed in the media as a book about the extinction of humanity, Dixon writes in the new introduction. But that was a faulty interpretation, he says. The disappearance of people was just an excuse to talk about evolution: let nature go wild without humans meddling with it, and see what happens. “It’s not about the extinction of man, it’s not a doom-laden thing,” Dixon tells The Verge. “It’s showing that life goes on and it doesn’t matter how much damage we do. The Earth will survive and will be repopulated. It’s a note of positivity rather than a note of gloom.”

No matter how it was received, After Man inspired the field of so-called speculative biology, where the principles of evolution fuel the creation of imaginary creatures and monsters. With the new edition out, The Verge spoke with Dixon about where he got the idea for After Man, how he created the animals in it, and whether the book would look any different if he wrote it today.

The interview has been lightly edited for brevity and clarity.

How did you get the idea for After Man?

It’s been something that had been brewing in my head for a long, long time. It’s going back to the 1960s. I was watching a television program with my father. That’s when the conservationists’ cry was “Save the Tiger!” My father said, “Why the save the tiger? If the tiger becomes extinct, something will evolve to take its place. That’s how evolution works.” And I thought at the time, that’s a very unconstructive attitude. As time went, studying biology, I realized that was actually the case. Things become extinct, other things evolve to take their place. So I used to think about what animal life might be like in the future. As a child, I was doing comic strips of strange beasts and so on. But then it died away for a bit.

It wasn’t until the mid 1970s that I met up with a friend of mine that I hadn’t seen for a long time and he was wearing a “Save the Whale” button. That sparked it all over again. Save the Whale? Why save the whale? If the whale becomes extinct, what could evolve to take its place? I thought, I can make a book about this. This is something we can use to talk about other natural processes of evolution in a totally novel way. There were plenty of popular level books on evolution going around at the time, but they were mostly books that looked toward the past — the dinosaurs, the development of the horse, and all that. It seemed to suggest that evolution is something that happened in the past and then stopped. That’s not the case. This way, by postulating theoretical things in the future, we can show evolution as a process that is ongoing.

How did you create all those creatures in the book? What was the process?

It was a matter of looking at the various natural environments and looking at what adapts particular animals for living in those environment. And if those particular animals died out, then whatever takes their place would have the same adaptations. Like, something living on a grassy plain. Nowadays, what do you get living on a grassy plain? You get antelopes, you get horses, things with long legs running away from enemies, and long necks so they can reach the grass, and very powerful chewing mechanisms so they can eat the grass, and usually long faces, so as they’re down eating the grass, their eyes are still quite high up and could look up for danger. So if antelopes and horses die out, whatever would evolve to take their place would have these same characteristics. That’s the sort of procedure that I used when trying to work out what was coming in the future.

What has changed in our understanding of evolution since the book was published?

The basic principles are still there, but we have access to a lot more details, especially at the cellular level, looking at DNA. That’s something I had no access to 30 years ago when I was putting all of this together. And of course, new fossil discoveries, new discoveries of animals that were living at the moment that were not known about at the time. Lots of [our understanding of] dinosaurs has changed. And that was the subject of my follow-up book, The New Dinosaurs. The speculation there was, if 65 million years ago, the meteorite had missed and the dinosaurs had continued to live and continued to evolve, what would they be like today? There I was talking about the concept of zoogeography: what animals live in what areas and what parts of the world, and why are they different from one another? It was like After Man. It was using fictitious examples to explain factual processes.

In the introduction to the new edition, you say that when you wrote After Man, you decided to ignore climate change as one of the drivers of evolution. Why is that?

I was presenting some very strange animals that looked very off and the reader might be a little bit put off by the sheer strangeness, but so I thought I could keep the background recognizable. So it was something to anchor it all. That’s a totally different approach from the one that we did with The Future is Wild. It was a television series about 10 years ago and I was involved in that as a consultant. It was the same sort of thing, looking at what animals might evolve in the future. But in The Future is Wild, the background was constantly changing all the time with new ice ages and new climate zones that don’t exist at the moment. It was quite a different approach.

In the introduction, you also say that “man, with his big feet and his big hands, has too much of an influence, twisting the course of nature away from anything that can be predicted.” How has humanity’s role changed in the past 30 plus years?

It’s an even more extreme version of what I was touching on there. But other aspects of it that I hadn’t appreciated at the time was the spread of mankind over continents has diminished our biodiversity a great deal. By taking rats on ships to various islands, the rats then devastate the ecology of those islands. In the 1980s, there were bigger issues, things like deforestation and monocultures, overfishing and overhunting. Those were the big obvious things that I was concentrating on at the time.

If you wrote this book today, would it look any different?

Probably not, because that’s all in there anyway. The big thing at the moment was getting rid of human beings so that the natural processes can get back to work and repair all the damage that’s been done and that’s still valid.

What do you hope readers get out of this book?

An actual appreciation of the wonders of evolution and of life in general. It is a book about life, about the wonders of life on Earth and how it’s a continuous process and not just something that has developed in the past to get us to where we are today.