Mankind has excavated almost every crevice of the earth; there is not one valley left unchartered, one land mass undiscovered or one mountain that has yet to be summited. For Dr. Spencer Wells, however, the question of how man came to inhabit the entire globe remains.Motivated to find answers to this and other enigmatic questions, Wells has made it his mission to trace human ancestry using genetic sampling.

Last April, 100 Brandeis students and faculty members participated in Wells' Brandeis Explores the Journey of Humankind program, which afforded them the opportunity to trace their ancestry and contribute to the expanding database of the world's migration patterns.

Wells, 38, is the director of the the Genographic Project, a five-year research partnership between IBM and National Geographic. The project charts humans' historical migratory patterns by analyzing the DNA samples of people from all around the world.

Wells discussed the Brandeis Explores the Journey of Humankind program and his overall research on human genetics in an Oct. 14 public presentation entitled "Deep Ancestry: Inside The Genographic Project."

The process of DNA testing in Brandeis Explores the Journey of Humankind was relatively simple for the students and faculty involved. Participants used cheek swabs to take DNA samples that they then submitted to a Genographic Project lab for testing free of charge.

Jeremy Wells '09 was a student in Prof. Peter Conrad's (SOC) class "Nature, Nurture and Public Policy," last semester when he heard about the project at Brandeis.

He agreed to participate in the project because he was curious to see what the tests would uncover about his genetic background.

"When you get the results you get to see all the genetic results going back to Africa," he says.

Prof. Sarita Bhalotra (HELLER) said she participated primarily to help expand the DNA pool available to the overall Genographic Project.

"My major interest was to be one more person to add to the database," she says. "Once more and more people do it, we can get to the point where we can look at more recent immigrations patterns."

Bhalotra marveled at the fact that scientists could pinpoint her ancestors' migratory patterns simply by examining her DNA.

"When [they] traced my DNA, they had no idea who I was," she says. "But for them to have been able to identify my direct maternal ancestry to the Indus valley, which is where my family originated from, is valuable information."

Although Dr. Wells aims to collect DNA samples from different populations across the world, he explained that he is particularly interested in the DNA of indigenous people. Indigenous societies' genetic lineage is better preserved because of their geographic isolation, which has not occurred for people whose families emigrated from their homelands.

In order to obtain the DNA of isolated populations, Wells and his team of researchers traveled to Chad. Wells said ongoing civil war has isolated Chadian citizens and has therefore prevented their DNA from combining with other populations' DNA.

"Some of the most fascinating places were isolated due to civil wars," Wells said.

Wells managed to get past Chad's tightly controlled borders and enter into the Tibesti mountains of northern Chad. Working in the Tibesti mountains, he collected DNA samples from tribal elders, who Wells said serve as a "link to history's oldest enigmas."

In the past, questions about human ancestry have been restricted to paleontologists who have attempted to trace human migratory history by studying fossil records, Wells said. Fossil records may provide clues about human migratory history, but Wells said they are too incomplete to providing a definite answer about human history.

"[Fossil evidence] gives fascinating possibilities but not probabilities," Wells said. He said that paleontologists eventually "reach a brick wall, as we call [it] in the genealogy community."

Wells said the genetic code embedded in the DNA samples he collected enables scientists to go beyond the brick wall and trace human origins all the way back to the earliest ancestors.

Wells explained that although most DNA is recombined when passed down from parents to offspring, some components of genetic inheritance remain stable: Mitochondrial DNA, which is inherited from the mother, gives scientists the ability to trace the maternal line to the oldest ancestor. Researchers can do the same using the Y chromosome.

Over the course of his research, Wells found that the "deepest split in the family tree is found in African lineages, which means they've been accumulating changes for long [periods of time]," he said. According to Wells, this split in African lineages proves that we all originated in Africa.

"We're all members of a small African family," Wells said.

Wells hopes that publicizing the concept of man's shared African ancestry will lead people to "rethink their view of race" and "get over their old-fashioned view of racism which has been perpetuated by racists."

Humans have 99.9 percent of their DNA in common, which is a "remarkably low level of variation compared to other species," Wells said.

"We're all effectively cousins, no more than 2,000 generations removed," Wells said.

Conrad noted that Wells' work conjoins many different fields of study in a unique scientific endeavor.

"It is so rare that you see a scientist that brings together science, history, anthropology and can communicate in a way that's accessible," he said. "It is an unusual opportunity to bridge issues."

Bhalotra agreed that Wells' work will make a social impact.

"[Wells'] work has real implications for helping people think about race," she said. "It has huge cultural, social and even political implications, some that we might perhaps not know.