By Isaac Kalembe Akiiki
Introduction: This is a review of Dr Henry Gee’s new book entitled, The Decline and Fall if The Human Empire*.
The review, which was undertaken by GrrlScientist’s Senior Contributor on May 11, 2025, is an entertaining and thought-provoking overview of the rise and fall of the human population – as our species declines towards extinction.
The review: Most people hold the romantic notion that the human species will go on forever and ever, amen, that we’ll conquer our horrible self-destructiveness along with myriad terrifying diseases as we pursue our rightful *Star Trek* lives exploring the cosmos.
It’s an appealing fantasy but we don’t have to look far to see how silly this notion is in reality.
Not only have all our closest evolutionary cousins gone extinct, but so has a significant portion of the planet’s biodiversity, from the smallest to the biggest of beings.
How soon? How long? In his latest book, Dr Henry Gee, writes: “Homo sapiens will disappear from the Earth within the next 10,000 years.”
In my opinion, Dr Gee is an optimist. Personally, I think humanity will go extinct within 1,000 years or, considering our self-destructiveness, sooner.
Not only is Dr Gee a prolific writer, but he is a scientist, so he builds his argument using the tools he knows best: science.
Structure: In the first part of the book, entitled *Rise*, Dr Gee sets the stage for his argument by sharing the latest information known about our evolutionary origins that began when the first bipedal apes popped up in Africa and moved out into the larger world about two million years ago, evolving new species along the way.
Despite our extremely patchy fossil record, we know that Homo sapiens are just one of many distinct hominin species that appeared during the last 315,000 years.
Probably the best known members of this group include the *Neanderthals* in Europe, the Denisovans in Tibet and the endearingly nicknamed “hobbits” in Indonesia – all now extinct.
Limited interbreeding: Thinly distributed across the globe, there were few opportunities for humans to interbreed with these other hominin species, so as a result, the modern human gene pool is very small.
Genetic variation: Making matters worse, humans went through several population bottlenecks, which further decreased their genetic diversity so there’s more genetic variation in just one small population of wild chimpanzees than in the global population of Homo sapiens, asserts Dr Gee.
Our lack of genetic diversity translates into an unfortunate future for us because it makes us susceptible to a variety of scary diseases and other issues that could quickly wipe us all out.
As Dr Gee notes: “As a species, humans are remarkably pox-ridden, worm-eaten and lousy.”
Homomins species: Although humans are the sole surviving Homo species, we weren’t the only inbred hominins on the planet.
Dr Gee writes that our close evolutionary cousins, the Neanderthals, possessed even less genetic diversity than we do, and that legacy put them at an even greater evolutionary disadvantage when competing with us for precious resources.
This forced them to either mate with us, their competitors, or go extinct.
Fossils – both fossil bones as well as fossil DNA – reveal that Neanderthals did both.
The Fall: In the second part of his book, entitled *Fall*, Dr Gee examines aspects of our more recent history that threaten our long-term future, particularly intensive agriculture.
Limited food variety: Modern agriculture has supported our explosive population growth but also makes us highly dependent on an extremely narrow range of foods.
Although seemingly miraculous, it’s no secret that modern agriculture provides us with a less than ideal diet and lifestyle.
However, one could argue that agriculture supports science and human ingenuity, both of which allow us to live longer and healthier lives than we ever did as hunter-gatherers.
Declining fertility rate: But our innovations have not necessarily served us well: Recent studies have found that humans are experiencing a sharp drop in fertility rates.
This is partially due to increasing levels of education for women, who discover meaning in their lives by pursuing activities other than motherhood, and also due to dramatically falling sperm counts – why?
No one knows. Tellingly, our once-runaway population growth is now slowing.
Need for action: According to Dr Gee, if we do nothing to address these issues: “The human population will sink to a level that is ultimately unsustainable, and extinction will beckon.”
A glimmer of hope: But in the third part of this book, entitled *Escape*, Dr Gee proposes a rather bizarre solution to our impending demise: establish colonies in space.
Space colonies: The spatial isolation of these colonies would aid humanity’s survival, argues Dr Gee, by allowing genetically distinct human communities to develop that could interbreed with people still living on Earth or elsewhere in space to produce offspring with the best qualities of both groups.
Really possible? But that said, this argument is undermined by the problematic reality confronting conservation biologists (and monarchists): small, isolated gene pools rarely recover their former diversity.
Further, human members of those communities often are hostile towards outsiders and become violent, even murderous, when newcomers arrive.
Inbreeding defects: These inbred communities will instead concentrate their genetic defects that increase their vulnerability to diseases, natural disasters and other mass casualty events – just what befell the Neanderthals.
In fact, intense inbreeding can explain nearly all the health problems faced by Europe’s royal families.
Limited lifespan: On one hand, building space colonies is advice that multi-billionaire robber baron, Elon Musk, would heartily approve of, but Dr Gee’s recommendation feels more like a stopgap measure to me. (Sorry, Henry.)
For example, it’s long been documented that all species have a limited life span, just as all individual creatures do: they are born, they mature, reproduce (maybe), grow old and die.
Historical evidence: In fact, Earth is littered with the fossilised remains of millions of foregone species, and despite being relative newcomers to the planet, there are more dead humans than living ones.
Even planets die.
Sourgraping? After reading this review, you may conclude that I disliked this book, but you’d be wrong. I enjoyed tremendously. It surprised me.
It made me rethink my ideas about the world and what its future may hold – and isn’t that one of the main reasons we read?
It’s like reliving one of those long arguments I’ve enjoyed in a pub, matching wits and arguments with my friends and acquaintances into the wee hours.
Conclusion: As an added bonus, Dr Gee’s writing includes, as always, some very evocative wording that is a pure pleasure to read.
This provocative and wonderfully well-written book will educate as well as stimulate many thoughtful discussions amongst people from all walks of life, and for this reason, it would be a fabulous read for both curious minds and for book clubs.
Highly recommended. About the author: Dr Henry Green is a British paleontologist and evolutionary biologist.
He is senior editor of *Nature*, a top-notch scientific journal.
The Decline and Fall of the Human Empire* (Pan Macmillan/St Martin’s Press, 2025) is his newest book.
About the reviewer: GrrlScientist writes about evolution, ecology, human behaviour and health. © Copyright by GrrlScientist | hosted by Forbes | LinkTr.ee (For comments on this story, get back to us on 0705579994 [WhatsApp line], 0779411734 & 041 4674611 or email us at mulengeranews@gmail.com).
