Epidemiology is the study of diseases and other health problems in human populations, particularly contagious diseases. Epidemiologists attempt to figure out when and where a disease first enters a human population, how it spreads, and how to prevent further transmission or incidence of the disease. They also study noninfectious diseases such as diabetes that can be related to the diet or behaviors of a population. Epidemiology involves a lot of detective work as well as statistical analysis. Epidemiologists can find work in government agencies such as the Centers for Disease Control and Prevention, public health research institutions, hospitals, pharmaceutical companies, universities, and more. An epidemiologist has a Master of Public Health (MPH), an M.D., or a Ph.D. degree.

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Epidemiologist in Action


Dr. Ben Muneta

Title: Medical Epidemiologist, Indian

Health Service

Education: M.D., Stanford University

In 1993 a mystery disease began to kill people in the southwestern United States. One of the experts that the Centers for Disease Control (CDC) consulted was Dr. Ben Muneta. Dr. Muneta is an epidemiologist, a scientist who studies the causes, transmission, and control of diseases within a population. He works at the Indian Health Service National Epidemiology Program in Albuquerque, New Mexico.

Dr. Muneta consulted a traditional Navajo healer. From him, Dr. Muneta learned that the disease was associated with extra rainfall, which had caused the pion trees to produce more nuts than usual. This in turn had led to a population explosion among mice that feed on these nuts.

Using this lead, CDC researchers determined that the disease was caused by hantavirus, a virus spread through the droppings of deer mice. With further research, Dr. Muneta confirmed that some Navajo healers had even predicted the 1993 outbreak.


An oceanographer studies the physical processes that occur in the sea. Oceanography includes marine chemistry, marine geology, physics, and biology. Physical oceanography is the study of the sea’s interactions with the atmosphere and Earth, including tides, weather, and climate. Chemical oceanography is the study of the chemical composition of ocean water and sediments, and the effects of pollution. Geological oceanography is the study of the sea floor both past and present, including its mountains, volcanoes, canyons, vents, and deposits of natural resources such as natural gas and oil. To work as an oceanographer, you will need a Master’s or Ph.D. in one of these subject areas. You can get started by earning a Bachelor’s degree in a physical or biological science.

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Oceanographer in Action


Ruth Curry

Title: Oceanographer, Woods Hole Oceanographic Institution

Education: B.S., Geology, Brown University

For Ruth Curry, spending time on the ocean waves has nothing to do with surfing or vacationing. She spends her time studying the ocean currents that affect our lives each day. Ruth Curry is an oceanographer at the Woods Hole Oceanographic Institute, an organization of scientists who research and study how the ocean affects the global environment.

Curry’s research focuses on the North Atlantic circulation and the currents that carry warm waters from tropical regions northward. As these warm waters reach higher latitudes, they release heat that warms the air above them and warms the climate of western Europe. As warm water cools, its density increases and it sinks to the bottom of the ocean. There it begins a southward journey back to the tropics. This conveyor belt of water plays an important role in maintaining Earth’s climate. Normally, the salinity, or saltiness, of ocean water stays about the same. But changes in global temperatures are melting large sheets of ice in Greenland, which is introducing large amounts of fresh water into the ocean. This fresh water is diluting the ocean water, making it less salty. A decrease in salinity makes ocean waters less dense and prevents them from sinking to the bottom of the ocean. Eventually, the melting of ice sheets in Greenland could cause the North Atlantic currents to slow and eventually stop, leading to dramatic changes in the Northern Hemisphere’s climate.

Evolutionary Biologist

An evolutionary biologist studies the origins and evolution of life and the relationships among Earth’s diverse organisms. Because evolution and evolutionary theory affects every aspect of biology, evolutionary biologists can focus their research on subjects as diverse as living bacteria, extinct marine arthropods, coral reef fishes, comparative anatomy, biodiversity of insects, and even human history. You do not necessarily need to major in biology to get started in a career in evolutionary biology, but you will eventually need a Master’s or Ph.D. in a physical or natural science, as well as a strong understanding of evolution, to work as a researcher or professor.

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Evolutionary Biologist in Action


Dr. Richard Lenski

Title: Professor, Microbial Ecology, Michigan State University

Education: Ph.D., Zoology, University of North Carolina, Chapel Hill

If you want to observe evolution in action, you must find populations that reproduce quickly. Dr. Richard Lenski, a professor at Michigan State University, has done just that. Dr. Lenski studies populations of E. coli bacteria, which he grows in flasks filled with a sugary broth. These bacteria produce about seven generations each day. Dr. Lenski has now observed more than 30,000 generations of E. coli.

The rapid rate of E. coli reproduction allows Dr. Lenski to watch evolution take place. Dr. Lenski can subject each generation of bacteria to the same environmental stresses, such as food shortages or antibiotics. He can then compare individuals from more recent generations with their ancestors, which he keeps in his laboratory freezer. By comparing generations in this way, Dr. Lenski can study how the population has evolved.

When Dr. Lenski began his research in 1988, watching evolution in action was still new. Now, many evolutionary biologists are following in his footsteps.

Conservation Biologist

A conservation biologist focuses on sustaining populations and protecting natural habitats, with the overall goal of preserving Earth’s biodiversity. Conservation biologists can work in all fields of biology, specializing in subjects as diverse as coral reefs, cheetahs of the African savannah, fish of the Amazon River, and the effects of climate change on polar bears. Because conservation work can involve economic issues and trade policies, many conservation biologists develop expertise in these areas. It’s also wise to have a lot of fieldwork under your belt. Some schools offer specific degrees in conservation biology, but many conservation biologists’ degrees are in broader fields such as ecology, genetics, or wildlife management.

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Conservation Biologist in Action


Angel Montoya

Title: Senior Field Biologist, The Peregrine Fund

Education M.S., Wildlife Science, New Mexico State University

In 1990 Angel Montoya was a student intern working at Laguna Atascosa National Wildlife Refuge in Texas. He became interested in the Aplomado falcon, a bird of prey that disappeared from the southwestern United States during the first half of the 20th century. Montoya decided to go looking for the raptors, and he found a previously unknown population of Aplomados in Chihuahua, Mexico. His work helped to make it possible for the falcons to be reintroduced to an area near El Paso, Texas.

Restoration of the Aplomado falcon became Montoya’s life work. He has monitored and researched the falcon since 1992. He helps release falcons that have been raised in captivity back into the wild, and monitors falcons that have already been released. It isn’t easy to keep tabs on a falcon, however. “Their first year they are pretty vulnerable because they haven’t had parents,” Montoya says. “Just like juveniles, they’re always getting into trouble. But I think they will do just fine.”

Cancer Geneticist

A cancer geneticist approaches the fight against cancer on a genetic level. One mission of cancer geneticists is to identify the role that specific genes play in cancer and determine if these genes can be controlled with drugs or other means. Another area of important research is how and why some cancers are more common among certain families or ethnic groups. By studying the relationships between genes and cancer, these scientists are reshaping medicine so that cancer will one day be more predictable, treatable, and preventable. To be a cancer geneticist you need a medical degree (M.D.) or Ph.D.

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Cancer Geneticist in Action


Dr. Olufunmilayo Olopade

Title: Director, Center for Clinical Cancer Genetics, University of Chicago

Education: M.D., University of Ibadan, Nigeria

Breast cancer occurs in many different forms. It has been most widely studied in Caucasian women but takes a very different form in women of African ancestry. Breast cancer hits women of African ancestry earlier and more aggressively than it does Caucasian women. Dr. Olufunmilayo Olopade wants to learn why. Working with scientists in her native Nigeria, Dr. Olopade compared gene expression in samples of cancer tissue from African women with samples of cancer tissue from Canadian women. She found that cancer cells from the African women often lacked estrogen receptors. This finding means that many of the standard treatments are not effective for this group of women.

Dr. Olopade’s work will have a huge impact on breast cancer screening and treatment in women of African ancestry. “Cancer doesn’t start overnight,” she says. “We can develop strategies for preventing it.”

Cell Biologist

A person whose focus of study is cell biology will find a variety of career opportunities available. These include jobs in education: individuals who are teachers, professors, or researchers. Cell biologists will also find opportunities in the healthcare industry, possibly working for hospitals or healthcare providers. In the area of public service, careers might involve working on initiatives that affect public policy, for example, tracking data on the incidence of AIDS or diabetes or communicating information to the public. Private industry also offers many opportunities, including companies that develop and market pharmaceuticals or medical diagnostic equipment and the financial institutions that invest in such companies.

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Cell Biologist in Action


Dr. Gail Martin

Title: Professor, Anatomy, University of California, San Francisco

Education: Ph. D., Molecular Biology, University of California, Berkeley

In 1974 Dr. Gail Martin was working at the University College in London when she made a huge advance. She developed a way to grow stem cells in a petri dish. These fragile cells were hard to work with, so Dr. Martin’s breakthrough removed a big obstacle to stem cell research. Seven years later, she made another key discovery while working in her own laboratory at the University of California at San Francisco (UCSF) in her native United Stateshow to harvest stem cells from mouse embryos. Her work has helped other scientists develop ways to harvest stem cells from human embryos and explore their use in treating disorders.

Dr. Martin likes to point out that her work shows how small advances in basic biology can pay off years later in unexpected ways. She states that many people focus on cures for specific diseases, not realizing that these cures “may come from basic research in seemingly unrelated areas. What is really going to be important 20 years from now isn’t clear.”


A geneticist studies how DNA and heredity affect the lives of humans and other organisms. The field of genetics is growing rapidly and spreading into diverse areas including medicine, agriculture, pharmacology, criminal justice, anthropology, epidemiology, law, politics, and more. Some geneticists are physicians who treat patients suffering from genetic disorders. Others are full-time lab researchers who work on developing genetically modified organisms, gene therapies, and other DNA-related projects. Geneticists also work in such diverse fields as conservation of endangered species, crime solving, and bioethics. Considering the explosive growth of this all-encompassing field, it is a great time to be a geneticist. Geneticists need a Ph.D. in physical science or an M.D.

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Geneticist in Action


Dr. Charmaine Royal

Title: Professor, Pediatrics, Howard University

Education: Ph.D., Human Genetics, Howard University

Many bioethicists focus on the ethical implications of technology. Dr. Charmaine Royal, however, is concerned with the ethics of experimental design and the applications and implications of biological research. Dr. Royal, who is a geneticist at the Human Genome Center of Howard University, points out that some scientists in the past tried to use genetic research to justify treating non-Caucasians as inferior. She also notes that although there is no biological basis for any meaningful differences among races, many African- Americans are still suspicious of genetic research. Many, for example, have been discriminated against when an insurance company or a prospective employer finds out they have sickle cell anemia, which is a relatively common genetic disorder in African-Americans.

Dr. Royal, who is Jamaican, wants to ensure that African-Americans are included and treated fairly in research studies, and that they receive the benefits of genetic screening and genetic counseling. In 1998 Dr. Royal helped start the African-American Hereditary Prostate Cancer Study, the first large-scale genetic study of African-Americans to be designed and carried out by an almost entirely African-American research team.