Thursday, December 07, 2017

Pollyanna Discovers Pandora's Box

Ratting with terriers in Cornwall.

Back in August of 2004, I posted a piece ("The End of the Game") about something called viral immunocontraception. The basic thrust of this Australian mad-scientist scheme was to create a virus to sterilize entire populations of animals: fox, rabbits, people, mice, rats, carp, etc.

The chance for such a thing to run out of control and end "Life on Earth as We Know It"seems pretty obvious ... but apparently not to a small cadre of Australian scientists warmly embraced by Animal Right lunatics willing to risk killing off everything on Earth in order to prevent hunters from firing a shot.

Scientists are looking at ways that genetic engineering might be able to help control invasive and pest species by altering the fundamentals of wild animal reproduction.

This research is strongly supported by the Humane Society and other anti-hunting groups across the world. Click here for more information.

One does not have to be a hysteric to see that genetic engineering in the reproductive arena could have a very serious negative impact on wildlife all over the world. The history of humans playing God on Earth is a very ugly one and -- ironically enough -- has often led to invasive species that escaped the "theory" of science and ran amok in the world like Frankenstein....

What's the problem with viral immunocontraception? One problem is that scientists do not have a terribly good track record guaranteeing sterility. For example, not all of the triploid Grass Carp released into weed-choked golf course ponds in the U.S. turned out to be sterile despite scientist's assurance that they all would be.

Another case of non-sterility occurred when it was found that not all of the "sterile" fruit flies released in California to combat a small outbreak of the Mediterranean Fruit Fly were, in fact, sterile.

Compared to fish and flies, a mistake with a replicating virus would be very difficult to contain. "Whoops!" is not a comforting comment to make after you have released a self-replicating immunocontraceptive virus that has wiped out every rabbit on earth.

The good news is that in 2005, 10 years of no substantive progress in the field, the Australian scientists lost their funding.

The bad news is that CRISPR technology has now made gene editing very cheap and very accurate, so the Mad Scientist contingent is sure to pop up and they will in all likelihood be unstoppable.

Already up at bat: a plan to wipe out brown rats in all of Britain (and never mind if it was the Brown Rat that stopped the Bubonic Plague).

From The Telegraph:

Now experts at Edinburgh University believe that a process called ‘gene drive’ could solve the [rat] problem. It works by spreading infertility genes through a population, which causes a catastrophic drop in numbers over several generations.

A similar approach is already being tested in mosquitoes, to help control diseases like malaria and zika. But now the scientists want to find out it if could also work in mammals.

The technology uses the DNA editing technique called Crispr, a natural process by which bacteria fight off viruses by snipping away at their DNA.

The rodents would be genetically modified in the laboratory before being released into the wild where they could mate with the native population.

Professor Bruce Whitelaw, of the University of Edinburgh’s Roslin Institute, where Dolly the Sheep was created, said: “For the first time we have the makings of technology that could reduce or eliminate a pest population in a humane and species-specific manner.

“Crispr is perhaps the most exciting tool that has ever hit biology, and it is a fantastic tool for us to pull apart the function of genes and how the animal or plant functions.

“It’s time to explore what this technology can do.”

Right. The reporter on this piece has misspelled the word -- it's CRISPR in all caps, and to say it is a "natural process" is to suggest that the atom bomb is too.

As for the scientists who want to wipe out rats, I assure you that they have spent too little time thinking of the negative follow-on as other species (such as the black rat) fill in the ecological niches created, and as other species (such as snakes and fox) collapse from declining food sources.

As I noted back in 2004:

Scientists, after all, imported the cane toad to Australia as a way of controlling insects in the sugar cane field -- the legacy is poisoned dogs and a country stinking from a billion crushed toad corpses on the highway. The toads did nothing to control insects, by the way, but they have speeded up the death of many small marsupials that have either been poisoned by the toads or eaten by them (the toads are as big as dinner plates and can swallow a sparrow whole).

Scientists said introducing the Indian mongoose onto Caribbean islands would be a good way to control snakes that were decimating native bird populations there. Those same scientists were surprised to learn that the mongoose and the snake kept very different hours in the Caribbean and rarely saw each other -- leading the mongoose to turn to bird eggs and small hatchlings as a source of food. Rather than slow bird loss, mongoose introduction speeded it up!

It was also a scientist who brought the gypsy moth to the U.S. as part of a hair-brained scheme to start a silk worm industry in this country. The actual result, of course, was the destruction of vast stretches of forest.


But of course it would not end there would it?

If wiping out all the rabbits and fox in the world is not enough to give you pause, you might think a bit about where this is going. What can be done for rabbits and fox can easily be done for humans. It turns out that the the biology of mammal reproduction is not terribly different from one species to another as far as the zona pellucida protein is concerned.

The zona pellucida is the area where the egg and sperm unite, and which is effected by the genetically-modified virus that the scientists are experimenting with. The transgenic virus can do either of two things -- thicken the wall of the egg so that the sperm bounces off, or shorten the tail on the sperm so that it never reaches the "ramming speed" needed to break through the egg cell wall. Either way, fertilization does not occur.

Of course, a virus that merely left humans infertile may be the least of our worries. In their continuing quest to be helpful, the same Australian scientists working on an immunocontraception viruses for rabbits and mice have announced that a small change made to a "mousepox" virus made it incredibly more virulent and totally resistant to normally effective mousepox vaccines. They note that the same change can also be made to the human smallpox virus, with predictable results.

And so there we have it: Man's ability to fit and fiddle with the essential elements of biology and physics is the veritable opening of Pandora's Box. We would be wise to have someone other than Pollyanna at the table when the rules for use are crafted. I fear a small black box warning may not be enough.


Dan said...

If you look at modern owl pellets (formed from the regurgitated bones of what an owl has eaten) you will find that young rats form quite a large part of the diet of some owls.

If you look at archaeological deposits of owl pellets from the medieval period, you will discover to your great surprise that rats (whether block or brown) are rarely if ever found in owl pellets, and then only from coastal port towns.

Black rats are tropical animals, and Britain is beyond the northernmost point of their breeding range. Coastal towns have black rat populations continually topped up from imports from ships; black rats do not and never have lived and bred in the British countryside.

Bubonic plague was the cause of the Black Death, but it was not spread by fleas on black rats, but rather human to human via the pneumonic route, possibly also spreadying via cats which are peculiarly susceptible to pneumonic plague.

Brown rats did not exterminate a pre-existing black rat population, but rather spread into a vacant ecological niche in Britain. They are certainly a pest and a plague, but as you rightly point out, they are a pest that we know about in minute detail. Research in New York, originally aimed at developing an animal model for menopause in humans, has now produced some interesting results.

It turns out that it is possible to produce a bait containing a pair of toxins, one of which causes menopause-like degeneration in ovaries, the other similar degeneration and infertility in testes. The bait doesn't kill rats, it merely renders them infertile and herein lies the magic.

Infertile rats hold down territories and prevent most immigration into those territories, but as they cannot breed, they never become much of a problem. As these sterile rats die off, more move in, take the bait and become similarly sterile, so the baited area maintains a low, territory-holding and somewhat xenophobic rat population which causes few problems and also repels other rats from the area.

The bait is not a transmissible virus. That's dangerous. It isn't even a toxin; the most that some numbskull drinking the stuff will suffer is infertility, which might be argued to be evolution in action anyway.

PBurns said...

You are wrong on black rats, which were endemic in Britain up to about 1700 when the brown rat (allegedly) showed up in a load of timber from Norway (hence the term “Norway rat”). The black rat was simply beat up and kicked out by the brown rat, a phenomenon that has occurred wherever the black rat once existed and where the brown rat was later introduced (such as the US).

Adding habitat injury to physical assault was that as thatch roofs became rarer in Europe, there were fewer dry places for the black rat to live – they want a warm dry location and are arborial rather than terestrial. For the record, no place in the UK is farther than 70 miles from a port, and most of the major metropolitan areas of the world are within 10 miles of a port.

You are right that the contagious black plague that hit Europe the hardest in 1300 appears to have been carried by coughing – a pneumonic version of the rat-borne disease. But the original source carrier of the plague itself was the black rat flea.

As you say, black rats are often found around ports where they enter, but they are not confined to wet locations nor are they unable to handle cold weather; they are found all over the world, and though they do not do terrifically well in cold areas, they are adapt climbers and are found in buildings as for north as central Norway. That said, like brown rats, roachesm pigeons, and feral cats, they are rarely found far from human habitation.

Jennifer said...

This isn't a problem of mad scientists. Scientists alone are not responsible for introducing species that became plagues. They had to have consent and cooperation from regulators, who in retrospect were insufficiency critical, and may have been pressured by interest groups, eg, agricultural organizations. Some biological controls have succeeded, eg, in Australia, control of Opuntia ssp by the Cactoblastis moth has been very successful, and Caliche virus seems to be helping to control rabbit numbers. You can hardly blame scientists for the hundreds of noxious weed species that are spread world-wide, or the monster-pests that mess up marine ecology. Sure, some extreme and dubious 'solutions' will be advocated by scientists who have use of powerful gene editing tech. I suspect most such scientists, if questioned, will respect the precautionary principle. Science has a lot of potential, and present US government is pretty hard on science in general. Scientists will continue to come up with new possibilities, some awesome, some terrifying. Decision making and popular literacy about science issues need improvement. I hate to see the problem constructed as one of 'mad scientists'.

tuffy said...

humans never hard is it to think about Nature in the big picture?