I Hate Rats - Especially the New, Improved Model

Let's get one thing straight: I hate rats. Never liked 'em, never will. Blame it on the movie "Willard" -- you know the one -- about the squirrelly looking guy with no friends who raises hundreds of rats and then they all turn on him at the end of the film. Anyway - rats suck, make no question about it. So imagine my surprise when I discovered that a group of researchers in Australia discovered a new breed of rat -- a super rat if you will - a black rat that is spreading its own vicious brand of disease all over the world and even some parts of Detroit.

According to findings presented at the 2008 Archaeological Science Conference, potentially fatal rat-borne diseases, such as typhus and leptospirosis, are likely to spread farther around the world thanks to the efforts of this new heavyweight rodent.

Researchers led by mammalogist Ken Aplin of Australia's Commonwealth Scientific and Industrial Research Organization (www.csiro.au) compared DNA sequences from 170 urban and wild black rats from around the world to create a sort of rat-family-tree. The data they collected allowed the team to track the rat's prehistoric and modern migrations and to investigate its impact on people in modern times.

What the researchers discovered was not exactly good news. It was no secret that black rats wreak havoc on agriculture, especially in Asia, and remain a major source of human disease.

But according to www.australianarchaeologicalassociation.com, the rodent is much more genetically diverse than previously thought. Aplin and his team identified a whopping six lineage of rat, each of which could turn out to be a separate species. According to the genetic data, the first strain of this pest first appeared in Southeast Asia about a million years ago.

This is itself is enough to make me want to stand on a chair. But since Aplin's discovery it's been hypothesized that the rodent has been on a global march. The study revealed high genetic variation among Indian rats, suggesting that the pest in India naturally, long before modern humans evolved. According to Aplin's study, one group of Indian rats invaded the Middle East. But it didn't stop there: the black rat then colonized Europe, says Aplin -- probably traveling with the first farmers and using Europe as a launch pad with sailing ships as the perfect transport. In short order, the rodent spread to the Americas, Africa, Australia, and the islands of the Indian Ocean and eastern Pacific.

According to www.bio-medicine.org, another two of the six lineages dispersed around Southeast Asia and the western Pacific during prehistoric times and more recently made landfall on other continents, the study showed. One of those lineages lives as a sort of rat ethnic minority, along with the dominant European group, in California. That suggests a second wave of migration to the Americas, perhaps during the gold rush of the 1800's.

So what's the future hold? Rats -- most researchers agree -- are a durable species that die hard and to make matters worse, the little buggers haven't stopped invading new territories. Evidence has shown that rats have crossed oceans and entire continents thanks to hitching a ride on cargo ships and vehicles.

That could lead to an increasing spread of the diseases that black rats transmit, such as typhus and leptospirosis. The team's comparison of known disease epidemiology and its own genetic results suggest that each group of black rats carries its own variant maladies. For example -- www.theage.com.au points out that the Seoul virus -- a rat-borne disease well known in Asia --- turned up out of nowhere in California in the 1990s, killing several people and taking medical authorities by surprise.

Guess what - researchers are expecting that sort of thing to continue with increasing frequency.

All I gotta say is if there was ever a time to develop a better mouse trip, that time is certainly now.