%0 Journal Article %1 person1960mechanical %A Person, Oliver P. %D 1960 %I Ecological Society of America %J Ecology %K demographic_stochasticity density-dependent_regulation ecology mechanical_simulation population_dynamics simulation %N 3 %P 494--508 %T A Mechanical Model for the Study of Population Dynamics %U http://www.jstor.org/stable/1933324 %V 41 %X TThe machine described in this report was con- structed at a time when analog computers were becoming fashionable. I had hoped to use it in a study of the complex changes in population structure that accompany changes in the reproductive rates and mortality rates of different age classes of populations of small mammals. It soon became apparent that the machine was capable of "solving" various kinds of problems put to it, but that preparation and calibration of the machine for each problem was too time-consuming to make it useful for solving witlh dispatch a series of problems. More important, it soonl became ap- parent that for not a single species of wild mani- nial were there adequate field data to feed into the machine to enable it to analyze to the full limit of its ability the population problems for which it was designed. In the process of putting ques- tions to the machine, however, the operator fre- quently became aware of various aspects of the problem that mnight otherwise have been over- looked. To be sure, an astute mathematician could have foreseen all of these possibilities and made room for them in appropriate equations, but for the ordinary mathematically impoverished field biologist the machinie proved to be a valuable intellectual crutch. It is also a stimulating teaching device that gives one the intellectual and esthetic satisfaction (and excitement) of being able to watch a population responding to the various aspects of reproduction and mortality that tend to keep its numbers in equilibrium. It should be pointed out that I have designed the machine to function in the manner that I be- lieve populations function in the wild. Conse- (ue:ltly, it is nothinig more than a mechaniical ex pression of my own notions about popu'ations and as such is perfectly capable of reproducing over and over all of the misconceptions of its designer. THE MODEL Essentially the model consists of a long in- clined plane into which a large number of holes has been drilled and down whiclh balls are per- mitted to roll. It resembles a metamerically elon- gated pinball machine (Figure 1). As long as it remains on the surface, the ball represents a living animiial; when it falls through a hole it represents a dead animal. Balls that "survive" long enough are lermitted to "reproduce," thereby contributing to the maintenance of the population. Numerous em)bellishments, however, are necessary before the model becomes rewardingly analogous to a wild population, and these will be described below.

@article{person1960mechanical, abstract = {TThe machine described in this report was con- structed at a time when analog computers were becoming fashionable. I had hoped to use it in a study of the complex changes in population structure that accompany changes in the reproductive rates and mortality rates of different age classes of populations of small mammals. It soon became apparent that the machine was capable of "solving" various kinds of problems put to it, but that preparation and calibration of the machine for each problem was too time-consuming to make it useful for solving witlh dispatch a series of problems. More important, it soonl became ap- parent that for not a single species of wild mani- nial were there adequate field data to feed into the machine to enable it to analyze to the full limit of its ability the population problems for which it was designed. In the process of putting ques- tions to the machine, however, the operator fre- quently became aware of various aspects of the problem that mnight otherwise have been over- looked. To be sure, an astute mathematician could have foreseen all of these possibilities and made room for them in appropriate equations, but for the ordinary mathematically impoverished field biologist the machinie proved to be a valuable intellectual crutch. It is also a stimulating teaching device that gives one the intellectual and esthetic satisfaction (and excitement) of being able to watch a population responding to the various aspects of reproduction and mortality that tend to keep its numbers in equilibrium. It should be pointed out that I have designed the machine to function in the manner that I be- lieve populations function in the wild. Conse- (ue:ltly, it is nothinig more than a mechaniical ex pression of my own notions about popu'ations and as such is perfectly capable of reproducing over and over all of the misconceptions of its designer. THE MODEL Essentially the model consists of a long in- clined plane into which a large number of holes has been drilled and down whiclh balls are per- mitted to roll. It resembles a metamerically elon- gated pinball machine (Figure 1). As long as it remains on the surface, the ball represents a living animiial; when it falls through a hole it represents a dead animal. Balls that "survive" long enough are lermitted to "reproduce," thereby contributing to the maintenance of the population. Numerous em)bellishments, however, are necessary before the model becomes rewardingly analogous to a wild population, and these will be described below. }, added-at = {2024-04-14T17:13:37.000+0200}, author = {Person, Oliver P.}, biburl = {https://www.bibsonomy.org/bibtex/20aa90147a5eeb366594ff126da9bb6e2/peter.ralph}, interhash = {fda9ee405c44c1005a6eb9ac2e46f396}, intrahash = {0aa90147a5eeb366594ff126da9bb6e2}, issn = {00129658, 19399170}, journal = {Ecology}, keywords = {demographic_stochasticity density-dependent_regulation ecology mechanical_simulation population_dynamics simulation}, number = 3, pages = {494--508}, publisher = {Ecological Society of America}, timestamp = {2024-04-14T17:13:37.000+0200}, title = {A Mechanical Model for the Study of Population Dynamics}, url = {http://www.jstor.org/stable/1933324}, urldate = {2024-04-14}, volume = 41, year = 1960 }