The Weekly Scientist on the Mighty Roach

If you’ve ever found yourself listening to an entomologist drone on about his love for critters and all things yucky, meanwhile wondering what all the fuss is about, you clearly haven’t heard of the cockroach — or you have and are just suffering from a serious case of student apathy. You might not know this if you are about as likely to check up on insect facts as munch away on a bowl of live wasps, but the cockroach is said to have emerged an astronomical 300 million years ago, way ahead of the modern day human, who came about circa 2 and half million years later. Consider this: these little vermin, which you are used to stomping, bludgeoning or sledge-hammering to smithereens upon immediate sighting, once roamed the earth with the likes of the Tyrannosaurus Rex and the Brontosaurus. The latter two might have long faded into the annals of evolutionary history, but the cockroach is still here and doing pretty darn well for its age. If that doesn’t fill with you some new-found respect for insects…..

Now arises evidence that these kitchen pests might just end up outlasting the human species. Myth-busters might have blown all of that “Nuclear-Holocaust-proof” business out of the water, but contemporary researchers are putting the Mighty Roach back into the race for Earth’s post-apocalyptic inheritor. Throw in two wildly varying doomsday scenarios and it seems, cockroaches are likely to do much better than us in the long haul.

Doomsday Scenario Numero Uno: Global warming, and Planet Earth is drying up, fast. According to research at the University of Queensland, when subjected to dangerously arid conditions, cockroaches can hold their “breath” for up to seven minutes. In the absence of a lung as we humans know it, insects have evolved a rather simple, yet efficient means for respiration. Air is taken up via little punctures in the exoskeleton (scientifically referred to as spiracles) and transported along microscopic tubes directly into tissue cells. Sounds nifty, but scientists have known for a while now that these tubes are also the very apparatus for moving water around the body. Thus, via natural osmotic processes, a lot of it can be lost over the course of one respiratory cycle. To compensate for this detrimental risk, cockroaches “breathe less” in lower humidity — they constrict their spiracles and keep these open for much shorter. This might sound like a bit of a stretch to us sceptics, but scientists purport that, come global warming and its compulsory background theme of Ride of the Valkyries, this breath-holding feat will come very much in handy.

George McGavin, of the University of Oxford, claims: “Two hundred and fifty million years of physiological fine tuning has produced a creature that will be around for a long time to come. Cockroaches will do well in the face of climate change.”

“Do well” as in survive-and-get-on-with-it-like-nothing-ever-happened or ascend-to-world-domination-once-the-last-human-has-dropped-dead? I hope it is the former.

Doomsday Scenario Numero Dos: Superbugs! The invisible enemy! You can run, but you can’t hide…In case you haven’t heard yet, right here, at the University of Nottingham, a team of researchers have uncovered a possible solution to the superbug dilemma. Dr Naveed Khan and his colleagues inspired some long-needed scientific optimism when they found potent bactericides in the last place many of us would expect to find them — in the brains of pesky, little cockroaches.

“We have identified nine different molecules (proteins) in brain lysates that were toxic to bacteria”, says Simon Lee, a postgraduate member of Dr Khan’s team. “We hope that these molecules could eventually be developed into treatments for E. coli and MRSA infections that are increasingly resistant to current drugs. These new antibiotics could potentially provide alternatives to currently available drugs that may be effective but have serious and unwanted side effects.”

As a matter of fact, tissues extracted from the American cockroach (Periplaneta americana) managed to kill more than a whopping 90 percent of Methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli without doing any damage to human cells. This means that these substances could effectively be used as antibiotics in the near future. One must admit, the prospect of vanquishing a sore throat with a tablet of cockroach-brain-antibiotic (of course, bearing some snazzy marketing name to fool the uniformed) takes some serious getting used to. Still, no sensible human being would rather explore the option of a gruesome, quarantined death. In England and Wales, MRSA-related mortality might have fallen by 37 percent in 2009, but we all know that we will only be allowed so long a respite from drug-resistant microbes before some new strain swoops in and sends a wildfire of hysteria throughout the country.

From a biologist’s point of view, this discovery might also explain why cockroaches are thriving unencumbered in the presence of some very malicious microbes. Lacking the rigorous immune system of higher organisms, insects should technically be even more prone to infections than we are. Producing these anti-bacterial proteins might be the insect’s answer to the problem, though why the brain is the only organ able to do so is up to ample speculation.

Either way, if we never get around to creating a better drug for MRSA, and the human race succumbs to a superbug pandemic like only the Daily Mail could have imagined it, guess who might still be around to enjoy our absence?

Yes, a ruddy cockroach.

Eric John

(Image courtesy of Steve Snodgrass)


Leave a Reply