Finding Human Identity Through Genomics - Identity Week


By Lisa Autz

Photo courtesy of D. Finnin/AMNH

Setting out to create your own family tree can be daunting, but how about creating a family tree for the entire living, human population? Given the fact that written acrophonic documentation only began about 3,000 years ago and some populations even lack such testimonies–you may ask, is that even possible?

Well, modern day geneticists claim that the true written documents of human history actually lie within us–in our DNA. The genetic codes in each of us contain thousands of identification markers that can trace humanity to one single ancestor.

The Genographic Project is a global initiative–gathering and analyzing the world’s largest collection of human DNA samples to understand human history like never before. Dr. Spencer Wells, a population geneticist and director of The Genographic Project at National Geographic, launched the mission in 2005 and has since had 630,000 participants from 130 countries.

The idea is to capture large samples of DNA by opening the project to the general public to participate. With the purchase of a $200 Geno 2.0 kit, participants swab their cheeks and are given raw gene data that can be traced on a computerized map of human migration patterns.

The scientific probability genetic testing provides has put into question many widely held beliefs in population migration. But for those rusty on their molecular genetics, you may wonder how exactly genes are so helpful at deciphering deep-rooted ancestral heritage?

The process is quite complicated, but a simple anecdote Wells delivers in this video boils it down succinctly. Suppose you are writing a thousand copies of Tolstoy’s War and Peace in eight hours (the time it takes for one of your cells to copy the genome). Just like there is good chance you will be making a typo every so often, our DNA makes low, measurable rates of about 100 mutations per generation. These typos or mutations then get passed down through the maternal, or mitochondria DNA, and paternal, or y-chromosome, to provide a sample of an individuals mutational gene heritage.

There are 150,000 of these identification markers that can be determined by the kits–identifiers that trace all of humanity back 2,000 generations to a small family from sub-Saharan Africa.

Dr. Michael Hickerson, assistant professor of biology at City College of New York, was so inspired by the Cornell Ancestry Project and his own ancestral exploration that he decided to have his undergraduate students involved in the global project.

In 2013, Hickerson developed the New York City Student Ancestry Project, an educational pursuit to convene 200 undergraduate students from eight different colleges in New York with the help of a 5-year career grant by the National Science Foundation.

The grant helped fund the Geno 2.0 kits bought for Hickerson’s Anthropological Genomics class. They kicked off the project in February with a swabbing event at the Museum of Natural History, just steps away from the Hall of Human Origins.

Hickerson spoke with BTR about how he thinks the project gives students an incentive to learn more about analyzing genetic information.

“One of the things I wanted to do here, in the course specifically, is have people learn how to interpret and analyze genetic data in general,” says Hickerson. “And what a better way to do that then actually have their own data from their own genome for an experiential approach?”

Hickerson’s personal research focuses on the genealogical history of organisms at a community level rather than human data. He explains to BTR the complexity and caution necessary when analyzing human genomes.

“Part of the process is just to understand how much of a dicey operation it is and how complex underlying records of genetic data can and cannot reflect your ancestry,” says Hickerson. “In my own family, I looked my dad’s gene up and he had this huge chunk of Native American [genomes]… it’s not in mine though… if I didn’t get my dad’s genome I never would have known about it.”

The explanation here is that each person inherits half of the genetic material from each parent, giving a slice of ancestral history, but not a complete one. The genetic footprints of our ancestral past, however, can make inferences on a much larger scale of humanity on the planet.

Diego Alvarado-Serrano, a postdoctoral researcher at Hickerson’s lab at CCNY, uses the raw DNA samplings and considers the spatial-geographic distribution of people in light of genealogical migration patterns.

Migration patterns are assimilated on computer programs that plot genomic data all over the globe. Alvarado-Serrano tells BTR about how the process is not necessarily a platform for discovery but rather gives greater probability to past assumptions.

“We are assessing the confidence we can have in what we already know,” says Alvarado-Serrano. “We can have a particular history seem even more likely.”

An example is the assimilation of the most recent Pleistocene glacial age that took place about 2.6 million to 11,700 years ago. Alvarado-Serrano uses the raw data and mimics probable migration that occurred from the north to the south of Europe when the northern region was covered in sheets of ice.

Climate shifts are a key motivator in human migration patterns and is currently a “hot topic” in the genetics field. Learning about the past and predicting future migration patterns due to climate change are particularly important in the current state of global warming.

Alexander Xue, a graduate student at the Hickerson Lab at CCNY, uses methods to make demographic inferences on the expansions of communities in response to climate change. On April 23rd, Xue will be giving a presentation at the American Museum of Natural History on for the project’s revealing event of the genomic analysis. Using data from 20 of the students, Xue uses a program method to cluster the student data into groups of genetic similarity and dissimilarity.

“I analyze the data using Principal Component Analysis,” Xue tells BTR of his work. “The data is collapsed into two axes of variations to recover overall patterns of geographic global genetic variations.”

Presented like a plotted map, this method can be seen in a similarly research done on a large group of Europeans method illustrates the degree of variance between the genetic data. A phylogenetic, or evolutionary tree, of the data is also made to infer evolutionary relationships between the genes.

The event will showcase the findings and analysis of the ancestry project along with panel discussions by geneticist and other scientists in the field. The American Museum of Natural History has agreed to facilitate the event as a public outreach to inform people on genetic examination from a purely ancestral perspective.

Robert DeSalle, curator in the Division of Invertebrate Zoology at the American Museum of Natural History spoke with BTR on how the museum is an appropriate place to host the project.

“Not a lot of people realize it but the museum is not just exhibits, it’s a full-fledged research institution,” says DeSalle. “New York City is such a diverse place and will be a good example of how people come together in one place and how our genomes get mixed up. It should be really interesting to see what these students learn about themselves.”