Recent years have seen one new virus follow another into the headlines. Zhang Shuyi, a researcher with the Institute of Zoology of the Chinese Academy of Sciences said, "If we humans want to escape from the worry and problems of viruses, we should not only invest in public healthcare and medical science and technology, but also show some respect by getting rid of the attitude that views nature as something to be conquered."
Zhang was the first Chinese ecologist to investigate and conduct field research in the tropical rain forests of the Amazon. He spent 19 months in the French national scientific research center located in the primeval forests of French Guyana. Early last year he was one of the scientists who found the relationship between the SARS virus and animals in the wild. And now once again, he has been focusing his attention on the relationship between human, animals and viruses as bird flu again hits the headlines in Asia
According to Zhang, the reasons for the continual outbreaks of viral diseases include the ability of viruses to mutate and changes in the ecological environment together with human population density and activities such as methods of poultry rearing.
"Despite the different paths they have followed, humans, animals and viruses are all natural life forms that have evolved over the millennia. At the fundamental level of existence there are no matters of right and wrong to distinguish among them," said Zhang.
Zhang points out that different species have interacted with each other in different ways during nature's long evolutionary processes. These interactions have contributed to making the natural world the way it is today. Some species have symbiotic or parasitical relationships with others. Some have found established their place in the food chain as predators and some as prey while some are both prey and predator. To better understanding a species, people should study not only the nature of the species' itself, but also how it interacts with the other species around it.
"Relationships between viruses and their hosts are much the same," said Zhang. "During the process of evolution, viruses will randomly test out all sorts of hosts. If a potential host's resistance is too strong it will not support the virus. If its resistance is too weak, the host may be completely overwhelmed and fall into extinction," he added.
According to Zhang, over a long period of time evolutionary mechanisms will lead to a broad equilibrium in the relationship between a virus and its host. It is in the nature of such relationships that the viruses live for generations in the body of their host and are then transmitted from host to host. The hosts on the other hand are able to withstand the viruses and have developed their own inbuilt mechanisms, which can prevent the viruses spreading out of control.
However, if a species encounters a strange virus and proves to be susceptible to it, then the lack of resistance in the host species will allow the virus to propagate itself unchecked leading to an outbreak of disease. This is when disaster can occur.
Zhang quoted Professor Michael Succow of the Ernst Moritz Arndt University of Greifswald, Germany saying that, "Humans should adopt systems and methods of production and farming which conform to the laws of nature. Such methods need neither large-scale equipment, nor veterinarians, nor vaccines and antibiotics that may prove harmful to the environment."
Zhang asks that we should control human population growth, lead well regulated lives, take care in domesticating wild animals, abstain from eating the creatures of the wild, avoid being in too close a proximity to wild animals, raise poultry humanly and coexist peacefully with the wild animals. He sees these as the most practical and effective means for us to deal with today's ever-present risk of disease.
What do you think? Can we afford to live at peace with nature or can we afford not to? Drop us a line at http://service.china.org.cn/j2ee/servlet/ecomment.client?cid=33890.
(China.org.cn by Li Jingrong February 18, 2004)
