Did you ever read the Andromeda Strain by Michael Crichton (not to be confused with A for Andromeda by Fred Hoyle and John Elliot, which was also a classic in its own right)? This 1969 techno-thriller has long been a favorite of mine, closely followed by The Terminal Man, which was published in 1972.

The idea behind the Andromeda Strain is that a military satellite returns to Earth carrying an extraterrestrial contaminant that kills everyone who comes into contact with it (apart from two inexplicable cases, which are — eventually — explicated). Toward the end of the book, the contaminant mutates into a new form that digests plastics, which leaves us on a bit of a cliff-hanger.

The reason I mention this here is that I just started reading The Andromeda Evolution by Michael Crichton and Daniel H Wilson (Daniel also wrote the thought-provoking Robopocalypse). I have to take my hat off to Michael for still publishing books more than ten years after he passed away in 2008, but such are the wonders of the modern world.

It doesn’t take long in the Andromeda Evolution before we discover that the Andromeda Strain is actually a bioweapon created by an alien intelligence, at which point things really start to go pear-shaped.

But that’s not what I wanted to talk to you about…

Early on in the book, there’s a paragraph that really grabbed my attention:

In the grand scheme of things, all human beings are part of the same family, regardless of origin.* The divisions we have built between ourselves along the lines of race and geography are illusions. If our species is ultimately able to see past these biases, it will be our shared genetic stamp of humanness that will outlive the cultural contrivances that distract us in our day-to-day lives.

There’s also an associated footnote that says: “*Based on modern genetic variance, it is estimated that an ancient and catastrophic near extinction event reduced the human population to a mere six hundred individuals. This tiny group of shared ancestors went on to give rise to all of us in our billions.”

Now, it’s not that I haven’t heard this before, but the way it was presented here really gave me pause for thought. I was also a little puzzled by the 600 number. I was sure that I’d previously seen a value of 10,000 or so. In fact, both of these numbers appear to be true, but at different times.

In his book Alone in the Universe, John Gribbin walks us through the past 600 million years detailing the unique series of events that were responsible for us being here. These include the Ordovician mass extinction that took place about 440 million years ago and wiped out 85% of all living species, the Devonian mass extinction that occurred about 373 million years ago and eliminated about 80% of life as we know it, the Permian mass extinction that knocked on our door about 250 million years ago taking out an estimated 96% of all living species, the Triassic-Jurassic mass extinction that took place around 200 million years ago eliminating around 50% of all living species, and the K-T mass extinction that took place 65 million years ago dispatching about 75% of all living species.

It is now widely accepted that a species of archaic humans called Homo erectus (meaning “upright man”) originated in Africa around two million years ago and later expanded out into Eurasia around one million years ago. It is also widely accepted that anatomically modern humans in the form of Homo sapiens (meaning “wise man”) evolved in Africa somewhere around 300,000 years ago, and that there were several “Out-of-Africa (OOA)” dispersals or migrations of modern humans across Eurasia, the most significant recent “wave” taking place around 70,000 to 50,000 years ago.

In A Brief History of Everyone Who Ever Lived, Adam Rutherford taught me more about DNA and genetics than I ever expected (or wanted) to know. Having said this, I must admit that I was interested to learn that I can trace my lineage back to Charlemagne (I was less enthused to discover that this is true of everyone today who is of even vaguely European extraction).

The point is that, via modern genome sequencing, we now know that there have been three close calls when humanity barely escaped extinction. The first occurred 1.2 million years ago when Homo erectus and related species were reduced to a worldwide breeding population of about 18,000.

Next, it was the turn of Homo sapiens, Homo neanderthalensis (Neanderthals), and Denisova hominins (the Denisovans). Sometime around 195,000 BC the world started to get a lot cooler resulting in much of the Earth being covered by desert or ice. By about 150,000 BC, it’s estimated that the human breeding population had been reduced to only around 600 individuals.

It appears that we were gamely fighting our way back when the Toba super-eruption took place about 70,000 years ago. To provide a sense of scale, the eruption of Mt. Saint Helens in 1980 ejected about one cubic kilometer of material into the atmosphere, while the eruption of Vesuvius in 79 AD ejected about three cubic kilometers of material. By comparison, the Toba super-eruption ejected about 2,800 cubic kilometers of material, which would have dimmed the sun for half a decade or more. It didn’t help that we were in the middle of another ice age at the time. The result was to reduce the worldwide human population to anywhere between 1,000 and 10,000 individuals.

As an aside, in Caesar’s Last Breath, Sam Kean explains how, with each breath we take, sextillions of molecules enter our lungs, some of which may have come from Caesar when he took his final gasp, others may bear traces of Cleopatra’s perfumes, and still others may have been exhaled by dinosaurs. But we digress…

I fear we are in danger of wandering off into the weeds. Let’s return to the point at hand, which is that — at one time in the history of our evolution — humanity was reduced to around only 600 individuals. Now, let’s pause for a moment to reflect on the fact that all of the ~7.8 billion people on the Earth today are evolved from those 600 remnants.

What this means is that it doesn’t matter what the color of your skin is or where you were born or what language you speak, and it doesn’t matter from which county or country you hail (although I think it goes without saying that Yorkshire, England is best). When push comes to shove, all humans are family and deserving of our respect (even the French). If we could remember this instead of focusing on our petty squabbles, and if we were more prepared to extend a helping hand rather than a clenched fist, I think we would all be a lot happier and the world would be a much better place. What say you?