You would think after the sound thrashing Michael Egnor received due to his mangling of the basics of evolutionary biology, the Discovery Institute might want to find someone else to quote in a guide for students. Nope:
“Microbiology tells us that bacterial populations are heterogeneous. Individual bacteria differ from one another. Molecular biology tells us that some bacteria have molecular mechanisms by which they can survive antibiotics. Molecular genetics tells us how these resistance mechanisms are passed to other bacteria and through generations of bacteria. Pharmacology helps us design new antibiotics that circumvent the bacterial defenses. What does Darwinism add to the sciences of microbiology, molecular biology, molecular genetics, and pharmacology? Darwinism tells us that antibiotic-resistant bacteria survive exposure to antibiotics because of natural selection. That is, bacteria survive antibiotics that they’re not sensitive to, so non-killed bacteria will eventually outnumber killed bacteria. That’s it.” (Michael Egnor, Quick, Nurse, Give the Patient a Tautology!)
They’re still quoting that moron (the post is from Dec. 31, 2007). I could repeat what I wrote at the time:
I’m going to spell this out really slowly so that even Egnor can understand (and here’s a picture that might help). In every bacterial population, there are pre-existing genetic variants that are resistant to antibiotics. When that population is exposed to an antibiotic, the sensitive bacteria die (or stop growing), while the resistant bacteria multiply. Over time, resistant bacteria (the resistance is genetically based) replace the sensitive bacteria: resistance genes become predominant. In other words, the bacterial population has experienced a change in genotypes–the genetic composition of the population has been altered. The change of gene frequencies in a population, in its most simple and reductionist sense, is evolution. (In fact [in this case], it is evolution by natural selection).
It would appear that Egnor has never met a single doctor who has had to decide whether or not to prescribe an antibiotic to treat a child’s ear infection. The reason doctors don’t always (or usually) prescribe an antibiotic is that they are concerned that unnecessary use of antibiotics will lead to the evolution of antibiotic resistance.
Of course, in light of yesterday’s post about how the frequency of different resistance genes could be explained by fitness differences, the above remark would be redundant.
Abort. Reboot. Retry.