<P> The theory that nature is permanently in balance has been largely discredited by scientists working in ecology, as it has been found that chaotic changes in population levels are common, but nevertheless the idea continues to be popular in the general public . During the later half of the twentieth century the theory was superseded by catastrophe theory and chaos theory . </P> <P> The concept that nature maintains its condition is of ancient provenance; Herodotus commented on the wonderful relationship between predator and prey species, which remained in a steady proportion to one another, with predators never excessively consuming their prey populations . The "balance of nature" concept once ruled ecological research, as well as once governing the management of natural resources . This led to a doctrine popular among some conservationists that nature was best left to its own devices, and that human intervention into it was by definition unacceptable . The validity of a "balance of nature" was already questioned in the early 1900s, but the general abandonment of the theory by scientists working in ecology only happened in the last quarter of that century when studies showed that it did not match what could be observed among plant and animal populations . </P> <P> Predator - prey populations tend to show chaotic behavior within limits, where the sizes of populations change in a way that may appear random, but is in fact obeying deterministic laws based only on the relationship between a population and its food source illustrated by the Lotka--Volterra equation . An experimental example of this was shown in an eight - year study on small Baltic Sea creatures such as plankton, which were isolated from the rest of the ocean . Each member of the food web was shown to take turns multiplying and declining, even though the scientists kept the outside conditions constant . An article in the journal Nature stated; "Advanced mathematical techniques proved the indisputable presence of chaos in this food web...short - term prediction is possible, but long - term prediction is not ." </P> <P> Although some conservationist organizations argue that human activity is incompatible with a balanced ecosystem, there are numerous examples in history showing that several modern day habitats originate from human activity: some of Latin America's rain forests owe their existence to humans planting and transplanting them, while the abundance of grazing animals in the Serengeti plain of Africa is thought by some ecologists to be partly due to human - set fires that created savanna habitats . </P>

Why is it important to maintain the balance of nature