Your (Ultimate) Origin Story

Thinking about: Your ancestry

As we have seen, genetic ancestry tests are misleading. When they trace your ancestry back to a region, what they are really telling you is that at a particular time in the past, many—or maybe even all—of your direct ancestors lived there. The period chosen, however, is arbitrary. In my case, go back two generations, and my direct ancestors all lived in America, but go back five, and they lived in Western Europe. So which should I regard as my ancestral origin, America or Western Europe?

Suppose we come up with compelling evidence that five hundred years ago, every one of our direct ancestors lived in Gwynedd, a county in northwest Wales. If we are a Feeler, we might be happy to wrap up our ancestral research and conclude that our ancestors were of Welsh descent—indeed, maybe even that they inhabited Wales since time immemorial. If we are a Thinker, however, we will be reluctant to do this. We will instead ask a question that is simultaneously obvious and easy to overlook: “Yeah, but where did those ancestors come from?” Thinkers, as we shall see, are inclined to ask “yeah-but” questions, often to the discomfort of those on the receiving end of them.

A Thinker will probably accept the conclusion, drawn by scientists, that humans have (continuously) inhabited Wales only since the last Ice Age ended, about 12,000 years ago. Likewise, they will accept the scientific consensus that if those Welsh ancestors traced their ancestry, it would ultimately lead them to Africa. As I have explained, if you are a human, you are ultimately of 100% African ancestry.

In theory, the person with the uniformly Welsh ancestry could extend their family tree back from Wales, all the way to their African ancestors—and beyond. After all, each person on their tree had two parents, who had two parents, and so on. As a practical matter, however, constructing such a tree would be an impossible undertaking.

In place of tracing the direct ancestors of the individual humans on their family tree, they could trace the evolutionary ancestors of their species. They will discover that Homo sapiens evolved from a species, which in turn evolved from a species, and so on, back through time. Here are some of the ancestral species they would encounter.

• Hominins (apes): ~7–5 million years ago (mya)

• Primates (shrew-like mammals): ~65 mya

• Mammals: ~210 mya

• Synapsids (mammal-like reptiles): ~305 mya

• Tetrapods (amphibian-like land-walkers): ~375 mya

• Fish: ~530 mya

• Worms: ~600 mya

• Multicellular organisms: ~800 mya

• Single-celled organisms: ~3.8 billion years ago

This, by the way, was not long (in geological terms) after the formation of the Earth, approximately 4.5 billion years ago.

At this point, it might feel like we have gotten to the bottom of things, but a Thinker will likely respond to our progress by asking another yeah-but question. “Okay, we can trace our ancestry back to very primitive single-celled organisms, but where did those first living things come from?” Here are three rival theories:

• Divine creation: God created life on Earth. This is at odds with what science tells us, but even if we accept that God played this role, we are faced with new questions. How and why did God do this, and more significantly, who or what created God?

• Extraterrestrial creation: The first living things on Earth came from another planet. They might simply have drifted here; they might have been planted here by aliens who visited early Earth; and not to be forgotten, aliens might have unintentionally introduced life to Earth, the way a careless lab technician might accidentally contaminate a petri dish. If we propose such a theory to a Thinker, they will likely respond with a yeah-but question: “Okay, aliens might have come from another planet, but how did life arise on their planet?”

• There was a series of fortuitous chemical mashups. This last theory—formally known as abiogenesis—is the scientific consensus. Over an extended period of time, molecules combined into complex organic compounds, which in turn interacted to give rise to self-replicating molecules. At that point, the evolutionary process took over, with the molecules most capable of self-replication becoming more numerous, at the same time as they were becoming more complex.

That such a series of events would take place seems like an extreme long shot, but realize that it could have taken place in any of the (literally) quintillions of planets in our universe, and that our universe has been around for nearly 14 billion years.

Even if life arising on Earth is a one in a quadrillion long shot, it is almost a sure thing that it would happen sometime, somewhere. We just happen to be the place—more likely, one of the places—where it happened. Lucky us!

Need more food for thought? Click here for my past essays, listed by title. Want to listen to rather than read my essays? Click here for narrations of my essays on becoming a Thinker, and click here for narrations of my essays on “applied thinking.” Narrations of my essays on becoming a Thinker are also available on your favorite podcast app. To play them, open that app and search for “Thinking More and Better,” and add episodes to your playlist.