Centre-stage at Roy Thomson Hall, a large projection screen implored the audience to “Get Social!” Listed underneath were a handful of Facebook and Twitter feeds for National Geographic, the event sponsor for last Monday night’s lecture on our genetic origins. The crowd was sizable, but perhaps not social-media savvy; most looked like someone’s ancestor already.
Still, they received Spencer Wells’ 90-minute talk enthusiastically. Boyish and sandy haired, Wells is a population geneticist and director of National Geographic’s Genographic Project, which is trying to piece together exactly how humans left Africa and ended up where they are today. “Essentially, we want to build a family tree,” Wells said. “So am I related to this guy?” A photo of a crumbling skull flashed onto the screen. “Or this guy?” Up popped a less dusty skeleton. “What about this guy?” Charlie Sheen’s mug shot. Everyone guffawed.
Since 2005, the project has collected over 500,000 DNA samples across 130 countries. Each sample contains genetic mutations, or markers—share a marker with someone, and you share an ancestor. If you follow markers like breadcrumbs, you can trace our earliest ancestors’ global migrations. Already, Wells’ team has determined that this trail began 70,000 years ago along a southern path through Arabia, and not, as previously suspected, a northern route through Egypt.
These days, Wells is interested in Chad, where a seven-million-year-old skull was recently found. “He’s called Toumai,” Wells said, “and he is your oldest ancestor.” In the audience, Shelby Steward, 22, whispered to her sister, “Grandpa?”
After the lecture, Shelby and Hayley, 26, were asked which Steward best resembled Grandpa Toumai. Hayley beat her sister to the punchline. “It’s Shelby,” she said. “The forehead is a dead giveaway.”
