Question Your World: Where Exactly Did We Come From?
They say “home is where the heart is,” or “you can never go home,” or “ET Phone home.” There are so many commonly used home-related phrases out there. Clearly we care a lot about what is home to us. Well, it just so happens that a team of researchers has recently used genetics, climate history, and contemporary indigenous tribes to try to answer that question. These researchers just announced that they have identified the region from which all of our modern human ancestors arose. Where exactly did we come from?
Everything has to start somewhere, sometime, right? For our human family, one of the oldest questions has been exactly where did we come from? Over the years, we’ve seen research putting the spotlight on discoveries that show us our earliest tools, art, and beyond. But the big question remains - where exactly did humanity come from? Well, lucky for us a team of researchers just announced they have located what could be our species’ ancestral home! Obviously, previous findings over the centuries have narrowed down our origins to Africa, but where exactly?
To find the answers, scientists took samples from members of a few indigenous populations and looked into the region’s genetic and climate history. Mitochondrial DNA was a very important part of this research because it’s passed down from moms to their children. Certain parts of it never change and continue to get passed on through the generations. Other aspects do change over time as we mate and mix and mutate - and our genetic information disperses over time. The never-changing parts make our mitochondrial DNA kind of like a time capsule letting scientists rewind the clock on human genetic history.
These scientists took this indigenous population and looked at their common genetic similarities in mitochondrial DNA, mainly what the oldest common mitochondrial DNA was. Since mitochondrial information allows scientists to peer back in time, they were able to see that this region’s genetic similarities trace back 200,000 years. Also, after studying over 1,200 blood samples from contemporary indigenous South African residents, researchers were able to pinpoint our genetic lineage to one specific sub-region.
This study pointed them to an area near Botswana, south of the Zambezi River. Using climate models and existing geologic evidence, the scientists were able to conclude that this region once hosted a vast lake and lush vegetation that sustained our earliest ancestors for 70,000 years! This oasis was surrounded by harsh desert until about 130,000 years ago when the Earth’s natural tilt, wobble, and varying shape of orbit turned much of that harsh desert into lush corridors, giving our earliest ancestors an opportunity to go wander, our first time truly leaving home.
This finding further ties human evolution to climate changes and has both climate scientists and geneticists excited about this discovery. After all you know what they say…there’s no place like home.
More on Human History
Human evolution is certainly a fascinating study and has driven curious scientific minds for quite some time now. The story of our human family involves harsh periods of survival, gathering in groups, inventing ways to survive, spreading across the planet, the evolution of domestic dogs, the development of cities, the invention of agriculture, and beyond. We love digging into human evolution and this new discovery about mitochondrial DNA helps us put another piece of the human history puzzle together.
Some of our favorite stories regarding human history have been turned into blogs and videos for you to explore. For example, who was the first toolmaker? Tools have certainly helped humanity do things, from staying warm on cold nights to landing people on the moon. Our innovative thinking and ability to make tools has given us a huge advantage over the animal kingdom and has opened up opportunities for us to live in otherwise unimaginable conditions (like onboard the International Space Station, for example!). Scientists have traced our early toolmaking past to an ancient relative of ours, homo habilis, who was making tools around 2.6 million years ago. However, another discovery is pushing toolmaking back to almost 3.3 million years and this predates the oldest fossils of our relatives, like Lucy the Australopithecine from 3.2 million years back. Who was this mysterious toolmaker? That question will require more research and study!
The study of human history also involves researching what came before humans! Our ability to walk upright is unique to our species. The human stride and gait has been very influential in shaping our family story. But which one of our ancestors began this bipedal tradition, paving the way for us to walk around one day? Previous findings have tied our upright lineage to an old relative. Dating back 3.5 million years, the Australopithecus fossil of Lucy being the most commonly known evidence of a bipedal fossil. However, a team of researchers did find something quite remarkable that is challenging where bipedalism may have come from. Lucy was discovered in Africa, but a fossilized set of footprints in Greece has the science community questioning where the first upright walking may have taken place in our family tree.
Stay tuned for more on human history as scientists around the world continue to work on completing the puzzle that is our past. Plus, it's always good to know more about our own fam, right?