“Hey look, a white squirrel!” This is not an unusual thing to hear where I live. Overall, the odds of seeing a white squirrel are very rare. But not in my town. I live in Exeter, Ontario, Canada, where white squirrels are quite common. Because of this, my wife Gail suggested this would make a good article.
There are a few other places in North America where white squirrels can be found, including: Marionville, Missouri; Brevard, North Carolina; Olney, Illinois; Kenton, Tennessee; Charlotte, North Carolina; Tallahassee, Florida; and the northern Florida Keys.
There is no single origin for these animals. Mutations in the genes that control pigmentation in fur, skin, and eyes are quite common in many mammalian species. Thus, it is no surprise that there are different causes for white eastern gray squirrels (Sciurus carolinensis). How it happens depends on where the mutation occurs in the pigment production pathway. Albino squirrels are easily identified by their red eyes. They produce essentially no pigment anywhere in their body. But these are more rare than other white squirrels. The more common variants have a mutation that causes the loss of pigmentation in the fur only. This condition is called leucism and is caused by a recessive allele.1 These squirrels can be identified by their black eyes, and they account for about 70% of all white squirrels in North America,2 including the ones in Exeter.
Variations like this are quite common. Sexually reproducing organisms inherit genetic information for various traits in paired form – half from mom, half from dad. There can be different forms (alleles) of a gene, so variation occurs among different offspring, depending on which alleles it inherited from the parents. Sometimes, a particular allele confers a survival advantage in a certain environment. For example, long-haired dogs in the Arctic are more likely to survive long-term than the ones with alleles for short hair. Over time, the long-haired allele gets passed on more often while the short-haired allele will be lost from the population. What has been called ‘natural selection’ is really ‘differential reproduction’. The one who has the most offspring wins. This is not evolution, because evolution requires a massive amount of information to be added to the genome. While the process described results in change, it is change in the wrong direction for evolution because any loss of pigment is a downhill change.
Back to white squirrels. As mentioned, these are a result of mutations. Over time, as cells divide and DNA is copied, copying errors (mutations) occur. Most of these are destructive, or neutral at best. Decaying genomes are a result of the Fall, when God put a curse on all of creation because of Adam’s sin. As a result, creation is subject to futility (Genesis 3:17-19; Romans 8:20) and everything now decays and dies. Since mutations are heritable and often not taken out by natural selection, they accumulate, resulting in something called genetic entropy. Occasionally, a mutation occurs that confers a survival advantage in a particular environment, such as wingless beetles on a windy island. But even these mutations are destructive and cannot be equated with ‘evolution’.
How do white squirrels survive? What advantage could there be in having white fur unless there’s snow all the time? You might say that doesn’t matter because squirrels hibernate, but these squirrels, even though do they spend a lot of time in their nests, don’t hibernate. Most of the year, having white fur is dangerous for a squirrel as it’s harder to blend in. A little patch of white on green grass is relatively easy for an airborne predator to spot. But does the survival of white squirrels in Exeter have anything to do with environment? No.
The answer lies with humans. White squirrels in Exeter date back to at least 1912, but it wasn’t until the 1980’s that they became a town symbol. White squirrels are now protected by a local by-law.3
This reminds me of those cute little dogs that can fit into a small purse. These would not likely survive in the wild, or even most neighbourhoods if they were free to roam around. Hmm. Maybe white squirrels could be the next purse accessory. By the way, these are not examples of natural selection, but rather ‘relaxed’ selection. The only way white squirrels or tiny dogs survive is by human intervention. It’s the opposite of what would normally happen in nature.
There’s no evolution here; just an example of the effects of the Fall coupled with human fascination for unusual things.