Natural Selection

Mankind messing with nature is always going to be regarded with suspicion.

It is the stuff of science fiction and. often as not, in literature and movies ending very badly for the perpetrators if the hero or heroine of the story triumphs or potentially for the whole population if the day cannot be saved by a great act of bravery or self sacrifice.

Throughout history, there have been more modest attempts to manipulate species to serve and benefit mankind.

The Egyptians introduced cats to protect their grain stores from infestation by rodents. The Mongoose proved to be an aid to keep snakes away from contact with humans in a home setting. In the UK the domesticated ferret remains both a pet and a working animal being a natural born hunter of vermin.

There have been some major errors of judgement in using nature against nature, however, which have had long lasting implications for the habitat and indigenous species of many countries.

Sparrows are now commonplace in many environments but were an example of the introduction of an otherwise alien species, in this case to control insect numbers which could threaten agriculture.

Perhaps the most well known misguided practice was the release into the wilds of Australia of Cane Toads in the 1930's to counter the damaging influence of Cane Beetles on the sugar crop. The decision to do this came from reports from Hawaii that the amphibian had been successful in increasing the yield and output of sugar cane on the Pacific Island. The outcome of an initial release of only 101 Cane Toads was a rapid invasion across the continent and with hindsight is now widely regarded as having been a bad idea.

Such mistakes have not however stopped scientific research and a recent initiative to reduce the global numbers of disease spreading mosquitos has shown initial success.

The mosquito, in tropical regions of the world, has had a devastating effect on the health of populations.

The insect is a carrier of fatal and debilitating diseases including malaria, West Nile virus, dengue (pronounced den-gee), yellow fever and the current newsworthy Zika virus.

To date the only weapons in the armoury against mosquitos have been chemical based, the widespread distribution of mosquito nets and control of natural environments.

The battle against mosquitos has taken a new form with a genetically modified version of the male of the species having been developed in a laboratory for release into the wider global population of the insect.

The male mosquito is not the core of the problem as it is the female that bites and spreads disease.

The GM male has been provided with a self limiting gene or "kill switch" which, after impregnation of the female causes the offspring to be born with only a short life expectancy.

The female population of mosquitos have not been able to differentiate the GM modified males from the natural males and in tests carried out in Brazil, Panama and the Cayman Islands the numbers of insects have been decimated by as much as 90% by the insurgency of the "friendly" mossies.

The Aedes Aegypti mosquito, the carrier of the Zika Virus has been shown as being vulnerable to the kill switch but it is only now that data has been compiled to show that, as well as the success of destroying mosquitos there has been a tangible reduction in the incidences of the disease itself.

This has given the green light to extend the GM scheme and it is planned for 3.3 million males to be released into the Zika affected zones over a 9  month period.

For all of the public fears and misconceptions over genetically modified anything a major selling point for the project is its claimed neutral impact on other species and the environment.

At best insecticides have a 30% to 50% success rate but they also tend to kill everything and with a risk of contaminants entering the human food chain.

The fate of the dominant male GM  mosquitos after they have had their way with the, lets face it, gullible and rather promiscuous native females causing the genocide of the species has not been mentioned in the discussion and research papers of the scientists.

I just hope that they do not grow to, say, prehistoric Pterodactyl size and prey on the now healthy and thriving Zika free population of children. Irony or what?