A method of operating a neural network for ecological and biological system modeling having a plurality of hidden layer neurons said method comprising: a plurality of network inputs and at least one network output, said plurality of neurons, each receiving a plurality of inputs applied to the network, reproduces the network using a regression model, and compares the output values with given target values, and using the comparison and goodness of fit to set the learning rules. The network does not require repetitive training and yields a global minimum for each given set of input variables.