The year 1665 was a difficult one for England. The devastating bubonic plague known as the Black Death was rampant in London. In the village of Eyam in Derbyshire, brave preacher William Mompesson sacrificed his life leading his flock to isolate themselves to prevent the spread of the plague after flea-infected cloth had been brought to the village from London. This amazing act of community responsibility prevented the spread of the terrible disease to the North of England. In London itself, the plague was only halted by the Great Fire of 1666, which destroyed much of the medieval city.
Although there is debate about the causes of the seventeenth-century plague, most suggest that it is spread by the rat flea, Xenopsylla cheopis, and it infects its host animal. The rat flea is a host to the bacteria Yersinia pestis, which is the actual infectious agent of bubonic plague. The host animal for the flea is the rat, and humans living in close association with rats can contract the plague. The plague is, therefore, spread to humans by bites from either the fleas or the rats. No wonder rats are regarded with both suspicion and fear in England.
Today, a familiar sight around UK food stores is the rat trap. These often comprise little boxes with a small entrance, appearing to offer an inviting shelter or even a nest for rats. But inside is a sample of rat poison.
Now, The Daily Telegraph has reported that rats in many parts of the UK have become resistant to rat poison.1 This is blamed on a mutation in the rats’ DNA that has caused immunity. The development is being pronounced by the media as an example of evolution in action. The Telegraph article did not include a reference to a scientific work, so it is difficult for us to comment on what has actually happened to the DNA. However, molecular geneticist and AiG speaker Dr. Georgia Purdom commented:
This news article is very vague, and although it talks about “tests,” it doesn't appear to be linked to any scientific article. Until a scientific article becomes available on the genetic alterations in these rats, all we can say is that the resistance is likely due to mutation(s) that have occurred in genes that are already in the rat genome (much like antibiotic resistance in bacteria). All observed mutations lead to a decrease in information—not the increase needed for molecules-to-man evolution.
This matches up with a previous example of rat resistance to poison in which the resistance came at a heavy price: arterial calcification and osteoporosis.2
The development of these so-called “super rats” is, therefore, an excellent example of natural selection. Natural selection, which is actually a conservative “force” in biology, works to eliminate less suitable organisms. The mutation would appear to have caused resistance to poison. Their non-resistant competitors are being wiped out by the poison. Therefore, larger numbers of the resistant variety are left.
It would be disingenuous, however, for any commentator to claim that they are watching evolution happen. “Rats turning into rats” is a concept that merely reinforces what the Bible means when it declares that God made each of the animals to breed “according to their kind” (Genesis 1).