I came across two startling headlines this morning while working on a manuscript about evolution acceptance and knowledge:
"Poll: Big Bang a Big Question for Most Americans"
"More people believe in bacterial evolution than human evolution..."
After reading the actual questions used in the Associated Press-GfK poll, I disagree.
Respondents were given a variety of statements which they rated from 'Extremely confident' to 'Not at all confident.' The topics included human evolution, the cause of cancer, vaccine safety, climate change, etc. But a closer look at the statements and responses indicates some big flaws.
For example, one statement reads "The universe began 13.8 billion years ago with a big bang." Fewer than 50% of those polled were highly or somewhat confident in the statement. It seems this statement was meant to assess American's confidence in the Big Bang. However, another interpretation of the statement is that it isn't so much about whether the Big Bang happened as it is about whether someone remembers when it happened. Personally, I'm not that confident I'd remember whether 13.8 myr is the best estimate produced by science, even though I've been watching the new Cosmos! I'd rate that as "Not too confident."
For evolution there are two questions: 1) "Life on Earth, including human beings, evolved through a process of natural selection." and 2) "Overusing antibiotics causes the development of drug-resistant bacteria." Respondents were more often at least somewhat confident in the statement about antibiotic resistance (>90%) than the one about human evolution (<50%), leading to the inference that people more highly 'believed' in microbial evolution than human evolution.
The major problem with this 'comparison of evolutions' is that the antibiotic resistant statement is incorrect. Applying selection pressure (in this case, antibiotics) does not cause drug resistant bacteria. Mutations and horizontal gene transfer cause drug-resistant bacteria. We've known that since 1943, when Luria and Delbruck showed that mutations happen first, then selection acts on that variation. The mutation timing misconception* is a frequent thorn we try to address in evolutionary biology and microbiology education, and it's too bad it's shown up in a national poll gaining a lot of headlines. The other problem is that 'evolution' wasn't used in the antibiotic resistant statement, and the word itself may influence how some people respond because they have different notions about what evolution is and isn't.
How would I score the evolution questions? I'd give the human evolution statement "Extremely confident" and the antibiotic question "Not at all confident."
How to improve the poll?
1) Pose the antibiotic resistant statement in a manner similar to the human evolution statement, perhaps "Antibiotic resistant bacteria, including MRSA, evolved through a process of natural selection."
2) Take out specific qualifiers that many people would be uncertain about, simply stating "Antibiotic resistant bacteria evolved through a process of natural selection." And "The universe began with a big bang."
3) Run the statements by some experts. A physicist might see the Big Bang statement differently than a biologist. Other microbiologists and evolutionary biologists will see the statements I came up with in a different way and have further qualifications.
* 'naive conception,' if you prefer
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