A parasitoid is an organism that spends a significant portion of its life attached to or within a single host organism in a relationship that is parasitic; unlike a true parasite, however, the parasitoid ultimately sterilizes, kills, and sometimes consumes the host. Thus parasitoids are similar to parasites except in the direr prognosis for the host.
Of course there is actually no clear separation between the concepts of parasitism and parasitoidy. Many species of true parasites can cause the death of their host- if for example they are present in overwhelming numbers or the host is in poor condition, or other compromising circumstances develop, such as secondary infections. In their extreme forms the categories of parasitism and parasitoidy are patently distinct; in general, however, there is a continuum of intermediate and contingent conditions that bridge the categories in practically every respect.
The human population bomb may be said to have exploded in 1945- the explosion has brought us from less than two to more than seven billion people on the earth today; we are swarming the planet and overloading the earth's capacity to support us. In spite of our technological advances in mass agriculture (while destroying vast necessary ecosystems and biodiversity) and our new industrial fishing techniques (creating of once rich oceans a spreading desert of marine life) - in 2012 each day over a billion people go malnourished.
This terrific explosion has resulted in a mass extinction of life- and will certainly destroy our present civilization with all the horror that will come with such a collapse.
What is to be done?
Kalinzskii
No comments:
Post a Comment