After Man: A Zoology of the Future by Dougal Dixon is a fictional non-fiction book proposing possible evolutionary tracks for the species that remain 50 million years after the Age of Man. As a fan of sci-fi and evolution, I couldn’t resist asking Dr. Ofria if I could borrow it when I spotted After Man on his shelf. As with most popular audience books, After Man doesn’t do a perfect job describing evolutionary events, but it is highly entertaining to read through. I also suspect that a very fun unit could be created around After Man for a high school or intro biology course.
After Man is split into three main sections: introductory material explaining basic biology and evolution, the main text describing animals as they may exist 50 million years in the future, and a final section wrapping things up and discussing the even farther future of Earth and its occupants.
I found the crash course introduction to evolution and basic biological functions to be quite effective if a bit dense. After Man tackles:
- basic cell genetics all the way from the basics up with no assumptions of previous knowledge
- natural selection rather briefly in this evolutionist’s opinion
- animal behavior and its genetic origins
- form and development including convergent evolution
- a rather simplistic view of food chains
- the potential origins of life
- the organisms that existed for the rise of humans
- the evolution of humans
Because each of these topics is given one to two pages (in a book with admittedly large pages), not much in-depth discussion is possible and mostly just the basic facts known in 1998 are presented. However, After Man has wonderful illustrations and figures for every topic and I found it more informative than some textbooks in that way.
Life After Man
After Man then jumps into the fictional but logical realm of the zoology of the future. It is clear that the author is quite comfortable with plate tectonics and its consequences since he carefully considers how the continents are likely to move over the next 50 million years and this features heavily in his analysis.
He progresses through each habitat of Earth, giving about a page to each “group” of animals such as large herbivores or small insectivores of that habitat. The habitats covered include:
- Temperate Woodlands and Grasslands
- Coniferous Forests
- Tundra and the Polar Regions
- Deserts: The Arid Lands
- Tropical Grasslands
- Tropical Forests
- Islands and Island Continents
Each page of text is accompanied with gorgeous full color illustrations of each of the animals mentioned, along with “handwritten” notes to further describe the animals. While these notes were quite a cute touch, they were a bit of a bear to read and I wish they were printed a bit larger.
The real draw of After Man, however, are of course the creatures that Dixon has dreamed up. Some of these animals, I found to be quite logical descendants from what will survive humankind’s destruction. Examples include:
- Rabbucks: The first animal of the future that we are introduced to is a descendant of the rabbit that has proliferated and evolved to fill a number of niches left by larger grazers. It made quite a lot of sense to me that an animal that is thriving in human-created environments would survive our extinction and be able to adapt to take over empty niches.
- Predator rats: Again, it makes quite a bit of sense that rats would outlast us and evolve to take advantage of resources left underutilized once we took out so many of the medium-sized predators. I also like that again there are many variations of predator rats (and they keep appearing in other parts of After Man) to the point that it could be termed Age of the Rats.
- Flightless auks: While quite similar to penguins in appearance, the auks live in the northern hemisphere so are unlikely to actually be descended from penguins. However, I’m mentioning them because Dixon takes the opportunity to introduce the idea of ring species because the auks surround the large polar ocean and speciated by the time their populations reconnected on the other side of the ocean.
- Pelagornids: Speaking of penguins, After Man proposes that they could evolve to release their egg later and later in life until they no longer needed to spend any time on land and evolved basically live birth in the ocean. This adaption would then free them to evolve much more efficient body structures for swimming and fishing with no need for those clumsy flat feet.
- Mud-gulper: After Man has a lot of examples of convergent evolution and the mud-gulper is a great one. While it looks like a hippo at first, After Man suggests that it could be a water-dwelling rodent that filled the niche left by the hippo and other large semi-aquatic grazers.
I have to say though, that I was skeptical about a number of the animals featured as possible future paths in After Man. Some of my favorite head scratchers were:
- Modern beaver: The beaver has adapted to have its back legs fused completely with its tail, to the point where its tail starts, and then it has some back feet sticking out of it before it continues to a typical beaver tail that we are familiar with. While the text claims this set-up doesn’t impede the beaver’s movement on land, I just don’t believe that from the illustrations. It just looks so darn awkward!
- Parashrew: This is an apparent descendant of the shrew that has grown a tail with a parachute made of hair. The young apparently use it to disperse on the wind and then lose the parachute when they first molt. I’m still trying to work out the physics on that.
- Swimming Ant-Eater: This ant-eater actually makes plenty of sense if you accept the premise of water ants. That is about where I get lost though. Apparently these ants evolved to make their nests floating in the water to avoid land-dwelling predators. Can they actually swim though?
- Slobber: I’m still not convinced that this animal wasn’t put in as a joke, just based on that name. They have apparently lost their eyesight entirely and rely on the smell of flowers from their tree and their excellent hearing to aim mucus strands at incoming insects and slurps them up. You really have to see the illustration to get the full effect though ;-).
- Nightglider: The nightglider is not actually descended from bats but looks very much like one (convergent evolution!) with the exception of the erectile spines completely covering its belly. It uses these spines to stab its prey as it crashes down on them. I’m just not sure how it then actually eats the poor creature given its head position and limbs.
After Man then spends a few pages discussing the even farer-flung future of Earth, including its eventual destruction by the Sun. I especially appreciated Dixon’s ideas for how major adaptations in plants generally then lead to major changes in herbivores, such as the emergence of flowering plants and seeds. He hypothesizes that plants could adapt to no longer drop their seeds and instead grow children attached to them (like some do already I suppose) and only root when an animal transports the seedling to a new location. This is a connection I hadn’t thought about before and is quite intriguing to add to my understanding of the evolution of life on Earth.
Potential Classroom Tool
While After Man is an entertaining afternoon read for biology buffs who also like science fiction, I see real potential in it being used as a supplement to a classroom unit on evolution. After Man does a wonderful job of showing how life on Earth is not fixed and things will continue to change long after we are gone.
However, After Man doesn’t have room to really dig into which current animals its proposed descendants could come from nor what specific adaptive pressures could lead to the proposed changes. There were a number of creatures that I was at first quite skeptical about and then realized they made a fair amount of sense once I thought through potential pressures and intermediate forms.
I could see an exercise using After Man proceed as follows:
- Everyone reads the book, obviously.
- Each student or team picks out a future animal that they would like to focus on.
- They use the suggested ancestor or (if none is suggested) try to determine their own from the Age of Man.
- They consider what adaptive pressures could have been in place immediately after the fall of man through to 50 million years to lead to the changes seen. This could include what niche opened up due to extinction, new niches created on that landmass due to continental drift, or biotic factors due to coevolution.
- Something I think wasn’t emphasized enough in After Man was the importance of the benefits or neutrality of intermediate forms. It would be important for students to consider how incremental changes could have been beneficial (or at least not detrimental) to allow the new traits to evolve. Of course some hitch-hiking could occur to explain a few traits, but hopefully not all!
- Perhaps the students can also discuss what limitations the ancestor has imposed on the evolution of the descendant.
I really love how After Man focuses on evolution moving forward, since so often we teach and discuss evolution as something that has occurred in the past. It seems like a valuable perspective to help students realize the fundamental mechanisms of evolution. Of course, if After Man were used in the classroom, I would recommend a strong caveat that evolution doesn’t actually proceed towards a goal as the language of After Man sometimes implies!
Have you heard of After Man? Do you think this could be a useful classroom tool? Do you have any recommendations to add to this very rough lesson plan?