Biology Now, 2e

26 ■ CHAPTER 02 Evaluating Scientific Claims

SCIENCE

articles, and popular science magazines such as

National Geographic, Popular Science, and Scien-

tific American are good secondary sources.

Eaton went to her local library and came home

with a stack of books, including a thick vaccine

textbook so that she could learn the underlying

science of how a vaccine works inside the body.

She read about how vaccines stimulate cells of the

immune system to protect a person from a virus

or bacteria. Once, while she was reading, Eaton’s

husband walked into the room and looked at her

with surprise. “What are you doing?” he asked.

“I’m looking for answers!” she replied.

For secondary literature on the Internet, try to

visit sites that are affiliated with the government,

a university, or a respected institution like a major

hospital or museum. Wikipedia often has over-

view articles that link to science blogs and review

articles in science journals. Like Eaton did, it’s

important to check the credentials of the person or

people behind a resource, especially on the Inter-

net. Anonymous sources are not to be trusted.

When evaluating a scientific claim, you may

need more detailed information than is available

in the secondary literature, especially if you’re

dealing with a particularly important life deci-

sion or if the area of science involved is changing

rapidly. In that case, you should next review the

primary literature, where scientific research

is first published (Figure 2.5). Primary sources

include technical reports, conference proceed-

ings, and dissertations, but the most important

primary sources are peer-reviewed scientific

journals such as Science, Ecology, and the Jour-

nal of the American Medical Association (JAMA).

Pulling from references she found in the

secondary literature, Eaton compiled a stack

of primary literature on vaccines. If her library

didn’t carry a particular journal, she acquired a

copy through interlibrary loan or, in some cases,

even e-mailed the journal directly and got arti-

cles for free. She found dozens and dozens of

papers about vaccines.

Correlation or

Causation?

One of the first papers that Eaton came across in

her investigation—one that had made huge waves

in the media—was published in the Lancet in

conflict of interest? Does he or she stand to make

money in any way if others accept those claims?

Doing scientific research almost always requires

money, so it is important to take into account

where the money comes from. In North Amer-

ica, the vast majority of basic research in science

is funded by the federal government—that is, by

taxpayers. Basic research is intended to expand

the fundamental knowledge base of science. In

the United States, Capitol Hill appropriates more

than $30 billion each year for basic and medical

research in the life sciences, including biomedi-

cine and agriculture. Researchers must compete

vigorously for the limited funds, and this compe-

tition helps ensure that public money goes toward

supporting high-quality science. Research funded

by the government is normally not considered

biased, since the funding comes from taxpayers.

But industries and businesses spend a great

deal of money funding science as well, often

in areas of applied research, in which scien-

tific knowledge is applied to human issues and

often commercial applications. In some cases,

researchers funded by industry may have a bias in

favor of whatever that industry is selling. Funding

from industry does not necessarily mean that a

scientific claim is incorrect, but the claim should

be looked at closely to rule out possible bias.

Offit, Eaton read, had worked with other

researchers to develop the RotaTeq vaccine against

rotavirus, a virus that can cause death from severe

diarrhea. The pharmaceutical company Merck

had purchased the vaccine, and Offit had received

an unspecified amount of money from that trans-

action. This financial compensation raised the

possibility that Offit might have some bias toward

the use of the rotavirus vaccine. Though she had

enjoyed Offit’s book, Eaton decided she did not

want to take his word alone as an answer to her

questions about vaccines. “In the end, I decided to

just read about it, do a lot of research, and talk to

a lot of people,” she says.

To t h e B o o ks

Eaton dove into the secondary literature on

vaccines. When investigating a scientific claim,

your first stop should be the Internet or the

library to get a basic overview of the topic from

the secondary literature, which summarizes and

synthesizes an area of research. Textbooks, review