• Spencer is a geneticist. He directs the Genographic Project, which studies prehistoric migration patterns of human populations. Following the clues in our genes, he has traced “humankind’s family tree” millions of years back to when the first humans left Africa.


    Spencer says he always had a “zeal for history and biology,” and that his interest in genetics came much later.

    One experience that made an impression on Spencer was when he and his family went to see the massiveKing Tut” exhibit as it toured the United States in the late 1970s. Spencer lived in Lubbock, Texas, and his family traveled to New Orleans, Louisiana, to see the exhibit. Once they got there, the line was so long, and the exhibit so popular, they had to wait 12 hours in the pouring rain to get in.

    “It was worth it, though,” says Spencer. “It just blew me away. The artifacts were about 3,500 years old, but they looked so new.”

    Spencer’s interest in biology was encouraged by his mother, who earned her PhD in the subject when Spencer was a boy. “It meant I got to hang out in the lab,” he remembers.

    Spencer enrolled at the University of Texas at Austin when he was just 16 years old, and earned a degree in biology there. He later earned his PhD in biology from Harvard University in Cambridge, Massachusetts. At Harvard, he began using genetics to trace the migration of humans as they left Africa around 50,000 years ago.


    “Getting to experience such diversity in the human experience, from Peru to Papua New Guinea.”


    “Making sense of the data” can be an exhausting and time-consuming process, Spencer says.


    “Understanding the world we live in, and who we are as a species.”


    Spencer and other geneticists study “human populations.” To a geneticist, a human population is a “coherent group of people,” he says. “They can share the same language, culture, or physical closeness. They are also able to interbreed, which is important for my work! That allows us to track genetic lineage and migration patterns.”

    One of the most surprising migration patterns that Spencer discovered was the first migration pattern. “The thing that still amazes me is how recently we left Africa. It happened only 50,000 years ago—that’s only 2,000 generations.”

    Spencer says tracing the routes of prehistoric human migration is important because it “lets us know where we come from.”

    It also shows us familiar patterns. Even thousands of years ago, people migrated for the same reasons they migrate today. “They’re either forced to migrate [by politics or conflict], they’re seeking better opportunities, or the climate has changed.”

    The data from the Genographic Project has also helped debunk what Spencer calls “inherent racism” in the genetic studies of just a generation ago. As late as the 1970s, scientists were studying human populations and attributing abilities and characteristics to their race.

    The Genographic Project and other genetic studies have shown that race is not a genetic marker at all. As fellow Explorer-in-Residence Wade Davis says, “Race is a fiction.”


    Spencer encourages students to study computer science and math.

    He points to Moore's Law, used to describe the speed at which computer technology advances. Moore’s Law says that that number of transistors that can be placed on a microchip doubles every two years.

    “In genetics,” Spencer says, the speed at which data accumulates is “five times faster every year.”


    Spencer encourages families to understand their own genetic journey—how their ancestors migrated, from where, and when.

    Geneticist: Dr. Spencer Wells
    Spencer Wells is a geneticist.
  • Term Part of Speech Definition Encyclopedic Entry
    accumulate Verb

    to gather or collect.

    ancestor Noun

    organism from whom one is descended.

    artifact Noun

    material remains of a culture, such as tools, clothing, or food.

    Encyclopedic Entry: Artifact
    biology Noun

    study of living things.

    characteristic Noun

    physical, cultural, or psychological feature of an organism, place, or object.

    climate Noun

    all weather conditions for a given location over a period of time.

    Encyclopedic Entry: climate
    coherent Adjective

    logically connected.

    computer science Noun

    study of the design and operation of computer hardware and software, and the applications of computer technology.

    conflict Noun

    a disagreement or fight, usually over ideas or procedures.

    culture Noun

    learned behavior of people, including their languages, belief systems, social structures, institutions, and material goods.

    data Plural Noun

    (singular: datum) information collected during a scientific study.

    debunk Verb

    to prove false or wrong.

    diversity Noun


    exhausting Adjective


    exhibit Noun

    display, often in a museum.

    Explorer-in-Residence Noun

    pre-eminent explorers and scientists collaborating with the National Geographic Society to make groundbreaking discoveries that generate critical scientific information, conservation-related initiatives and compelling stories.

    gene Noun

    part of DNA that is the basic unit of heredity.

    generation Noun

    time between an organism's birth and the time it reproduces.

    geneticist Noun

    scientist who studies the chemistry, behavior, and purposes of DNA, genes, and chromosomes.

    genetic marker Noun

    gene that is located on a specific place on a chromosome.

    genetics Noun

    the study of heredity, or how characteristics are passed down from one generation to the next.

    Genographic Project Noun

    National Geographic project that uses genealogy to trace the migratory history of the human species.

    history Noun

    study of the past.

    interbreed Verb

    to reproduce with members of a closed population (where genetic material from outside groups is excluded.) Or, to breed with members of another breed or group.

    King Tut Noun

    (1341-1323 BCE) nickname of Egyptian pharaoh Tutankhamun.

    Encyclopedic Entry: King Tut
    lab Noun

    (laboratory) place where scientific experiments are performed.

    language Noun

    set of sounds, gestures, or symbols that allows people to communicate.

    lineage Noun

    line of descendants of a particular ancestor.

    massive Adjective

    very large or heavy.

    math Noun

    (mathematics) study of the relationship and measurements of quantities using numbers and symbols.

    microchip Noun

    small semiconductor with electrical circuits that carry information.

    migration Noun

    movement of a group of people or animals from one place to another.

    migration pattern Noun

    predictable movements, in time and space, of a group of animals or people.

    Moore's law Noun

    observation that the number of transistors placed on a microchip can double every 18-24 months.

    PhD Noun

    (doctor of philosophy) highest degree offered by most graduate schools.

    politics Noun

    art and science of public policy.

    population Noun

    total number of people or organisms in a particular area.

    prehistoric Adjective

    period of time that occurred before the invention of written records.

    race Noun

    arbitrary grouping of people based on genetics and physical characteristics.

    racism Noun

    governmental or social systems based on the belief that one race or ethnic group is superior to others.

    route Noun

    path or way.

    species Noun

    group of similar organisms that can reproduce with each other.

    technology Noun

    the science of using tools and complex machines to make human life easier or more profitable.

    time-consuming Adjective

    taking a long time to finish.

    transistor Noun

    semiconductor that controls the flow of an electric current.

    Wade Davis Noun

    (1953-present) Canadian anthropologist and National Geographic Explorer-in-Residence.

    zeal Noun

    enthusiasm or passion.