What Comes After Homo Sapiens?
by Don Simborg
We’re all here right now, living on this planet. But who’s up next?
What comes after Homo sapiens?
That simple question naturally leads to several more. First, how will we know when Homo sapiens (Latin for “wise man”) has evolved into some other species (let’s call that Homo nouveau)? Further, when will that happen, and what will that new species be like?
And, since none of us may be around when this new species arrives, why should it matter to any of us?
As you’ll see as we move through the discussion in this book, it will matter a great deal. Further, it may be unlike any shift in species that came before it.
Let’s start by looking at an evolutionary image—one I’m certain you’ve seen in some form—that shows the progression of humans from apelike creatures to our current state (see figure below).
This book will attempt to fill in the partially obscured figure at the end of this progression—the one just to the right of the Homo sapiens.
The Homo sapiens that looks just like every one of us.
Why should we take an interest in this? For one thing, we’re the only species in the 3.8-billion-year history of life on earth that is even capable of doing that! We alone are equipped to ask those kinds of questions, let alone suggest possible answers. After all, the very concept of species didn’t exist until Homo sapiens defined it.
We’re also the only ones who have the tools necessary to effectively address those kinds of questions. No other species understands evolution, genetics and the mechanisms of speciation, among other concepts.
Perhaps most exciting of all, if and when Homo nouveau emerges, we will be the first species ever to be able to recognize that we have evolved into another one. That will be a singular event in the vast continuum of evolution.
But this also raises many puzzling questions:
- Who precisely will discover this? How will it occur? Will it be a sudden insight by some future taxonomist or will it come through careful study of fossil and genomic records?
- Will Homo sapiens still, in fact, exist when this recognition occurs? Will there be two Homo species coexisting? (If so, it won’t be for the first time.)
- Just who will do the recognizing: Homo sapiens or Homo nouveau?
- How will we get along? Will we get along?
Tack on some pertinent questions of your own and you can start to see what a significant and provocative topic we’re about to explore.
The Coming and Going of Species
It’s helpful to back up at this point a bit and review some facts for greater perspective. We know that more than 99 percent of all species that once existed no longer do. Species come and go—a seriously inconvenient truth. Additionally, their arrival and departure aren’t necessarily uniformly spaced. For instance, there have been relatively short periods when new species appeared in great numbers, like the Cambrian period 540 million years ago. In this case, “short” is still measured in millions of years.
Likewise, there have been relatively “short” periods of mass extinctions, defined as the loss of at least 50 percent of the species. There have been five such mass extinctions, the most recent one being 66 million years ago, which wiped out the dinosaurs and most other species. In fact, we may be undergoing a sixth mass extinction as we speak, which may be relevant to discussion later in this book. On the other hand, we believe some species like some cyanobacteria—bacteria that live through photosynthesis—have been on earth for billions of years and have survived these massive changes relatively intact.
Most species, however, came into being gradually over millions of years. Most have subsequently died out gradually over a similar amount of time through the process we call evolution.
So where do we—the species Homo sapiens—fit in? For one thing, we’ve only been around in our current form for about 200,000 years—a mere sliver of the time there has been life on earth. To illustrate this, stretch out your arms wide in each direction. The distance from the tip of your right middle finger to the tip of your left middle finger represents the total time of life on earth. If you trim either fingernail, you cut off the total time that Homo sapiens has been around—not very long! Further, chances are we won’t be around very much longer, evolutionarily speaking.
The Face of Evolution
Since we’re discussing the evolution of our species, let’s get a handle on what that involves.
Evolution occurs by random genetic change interacting with the environment. We’ll get into that in more detail later. But that broad statement leads to other more specific and compelling questions:
- Does it take just one genetic alteration to change a species—or thousands?
- How do we draw the line from one species to the next? Where’s the exact point where one species changes into another?
- Does species change happen over a small number of generations or are there increments of species change over many generations on some kind of continuum?
- If things aren’t so consistent, does that mean that it’s somewhat arbitrary when species change actually occurs?
Of course, there’s always the possibility that nature will toss aside some of the rules that governed evolution to this point. Maybe the transition from Homo sapiens to Homo nouveau will occur in a completely different manner. Maybe it will happen faster than it has in the past.
It’s also possible that completely new forces will play a role in this evolutionary change. Will Homo nouveau be induced by genetic engineering? By computers? By other technology? By a global catastrophe? Lastly, give some thought to the most remarkable possibility of all—will we ourselves be the ones who create this new species? In effect, will Homo sapiens create Homo nouveau?
Those are all powerful questions. The objective of this book is to address them as comprehensively as possible.
That said, a great deal of science and technology will be discussed. But you won’t need to be a scientist or particularly technologically savvy to understand and enjoy it.
On the other hand, I don’t want to exclude scientists and technologists. Through this book, I hope to generate discussion on this website. Hopefully, the scientists and technologists whose work I have covered will comment on my conclusions and provide their own.
Since the overall scope of this topic is so enormous, I have by necessity summarized and synthesized much of the research I cite. To some scientists and technologists in those fields covered, this may seem superficial, incomplete and even misleading and incorrect. I welcome such feedback here. My intent is to write not a science fiction story but rather a new story based on science.
The Greatest Challenge of All
Another interesting element to this project is that there are really no experts on this particular subject. That is because it is not a single field of study, but rather many. In that respect, there’s really no one who’s “qualified” to write about this topic, at least by the traditional definition.
That’s made this project an enormous challenge. But it’s what has also made this project so exciting—an excitement I’m certain you’ll come to share.
In his heavily researched book Cosmosapiens: Human Evolution from the Origin of the Universe, John Hands nicely summarizes the core challenge that this book addresses:
“To be a successful scientist today means spending a career on colloid chemistry or palaeoarchaeology or studying chimpanzees, or some equally if not more specialized field. This narrowness of inquiry has produced a depth of knowledge but has also carved out canyons of expertise from which its practitioners find it difficult to engage in meaningful dialogue with other specialists except where canyons intersect in a cross-disciplinary study of the same narrow subject.
“Few scientists transcend their specialist field to address fundamental questions of human existence such as what are we? The few who do rarely engage in open-minded debate. Too often they are unable to see the bigger picture and from their canyons they tend to fire a fusillade of views derived from the training, focus, and culture of the narrow academic discipline in which they have spent their professional lives.
Think about that for a moment. Eminent scientists, researchers and others possess extraordinary levels of knowledge and insight, yet rarely piece that together with other knowledge to address even greater questions. In a sense, the specific focus of their impressive credentials effectively creates a barrier that cripples their ability to gain greater perspective.
So, who then can see what these accomplished scholars often cannot?
You and me, for starters. Let’s attempt to cross those canyons.
My Preparation for Writing this Book
With regard to myself, my background in medicine and scientific research has prepared me well to undertake a project like this. I’ve published more than 100 peer-reviewed articles and have served on the faculty in the schools of medicine at Johns Hopkins and the University of California, San Francisco. My training and practice were in internal medicine, and my specialty is medical informatics—using computers for electronic medical records, diagnosis and other purposes. I founded and led two companies focused on clinical decision support and electronic medical records.
Although I have a strong background in medicine and scientific research, I'm not an expert in any of the fields this book touches on (evolutionary biology, genomics, paleontology, speciation, artificial intelligence, neuroscience and many more). This has allowed me to analyze the pertinent data without any sort of biased or filtered eye.
That, I suspect, is the same sort of perspective you as the reader will also bring to this book—a fresh, untouched viewpoint that will make our shared process of investigation and discovery all the more compelling.
Because I took on this project with an unbiased perspective, this book was a true investigation on my part—a pure learning experience. This was not an attempt to justify some preconceived theory on my part. Each avenue I explored seemed plausible at first. Some paths led to likely threats to our very existence, like artificial intelligence, which I now believe to be our greatest existential threat (a surprise to me.) On the other hand, nanotechnology, the branch of technology focusing on dimensions of less than the width of a human hair, could be either an existential threat or the savior of humankind.
There were a great many more surprises and unexpected paths to follow. Here are a few:
- I learned how brilliant and correct Darwin was for all the right reasons.
- I also learned how correct Jean-Baptiste Lamarck, the famous French biologist, was for all the wrong reasons.
- Gregor Mendel led us to an understanding of genetics that is dramatically oversimplified; his work was possibly falsified, yet Mendelian genetics is still foundational.
- Ray Kurzweil is predicting “the singularity is near.” Bill Joy is the cofounder of Sun Microsystems. They have opposite views of our future, but both are equally frightening.
- The genome—the genetic material of an organism—is so magnificent and complicated that it may take centuries for us to fully understand it.
- We have about the same number of genes as a mouse, but it is the epigenome—the part of the genome that regulates our genes—that really makes us human.
- I had never heard of the “species problem” before my research. I still don’t understand it.
- We don’t know for sure how and when Homo sapiens got here, but Svante Pääbo and his team are revolutionizing our understanding of human evolution.
- Our main differentiator is our brain, not our upright posture. We still don’t know why the latter evolved.
- Our tools to study the brain are brilliant examples of the epitome of evolution, but our understanding of how the brain works is still in the future.
- CRISPR will take us closer to the Methuselarity. You will soon learn about both.
I’ll save the discussion of these and other surprises for later in the book. The overriding point is that, unlike many scientists and researchers, my perspective was in no way limited by what I already knew or, perhaps all the more important, what I expected to find.
That’s an advantage you enjoy as well. So, let’s begin our journey.