Universe 25- John Calhoun's NIMH experiment

The work of Dr. John Calhoun at the National Institutes of Health in Washington DC has attempted to answer this question in a unique

experiment

that took years to complete. Dr. Calhoun used white mice to study population growth and its effects on individual behavior, in addition to his famous research work, he has recorded some of these observations on film in this 16-cell mouse habitat. Utopian conditions of nutritional comfort and housing were provided for a potential population of over 3,000 mice, but despite the ideal conditions, the mouse population suffered catastrophe. Individuals were monitored. Due to color markings on their fur, factors that normally control population growth were eliminated, such as predation by owls or cats, and communicable diseases were also reduced.

The Mouse Universe simulated the current situation of an ever-expanding population of humans to see how Dr. Calhoun's Mouse Universe works. grew we will use the family population graph again within the first 100 days the mice went through the period Dr. Calhoun called effort this was a period of adjustment territories were established and nests were made the next period lasted approximately 250 days the population of mice doubled every 60 days, this was called the exploitation period, the use of resources became unequal, although each living unit was identical in structure and opportunities, in some areas more food and water was consumed as it increased population, the majority of mice associated eating and drinking with the presence of others. and overcrowding developed in certain units, the third period consisting of 300 days found the mouse population stabilizing, this was called the equilibrium period.

Dr. Calhoun noted that new generations of offspring were inhibited, as most of the space was already socially defined at that time, by some unusual behavior. violence became noticeable excess prevailed males strove to be accepted were rejected and retreated huddled would exhibit brief bursts of violence against each other the effects of violence became increasingly visible certain individuals became targets of repeated attacks these individuals other youngsters would have chewed and severely marked Tails. The mice that grew to adulthood exhibited an even different type of behavior. Dr. Calhoun called these individuals the beautiful ones. His time was spent solely on getting ready, eating and sleeping.

They never got involved with other people having sex or fought. Everything seemed like a beautiful display of the species with alert eyes and a healthy and well-groomed body, these mice however could not cope with unusual stimuli, although they seemed curious, they were actually very stupid. Dr. Calhoun called the last period the death phase that drove the population to extinction, although the mouse utopia could In the 3000 house, the population began to decline in 2200, in the shift from the equilibrium phase to the After dying, each animal became less aware of the Associates even though all the animals were pushed closer together.

Dr. Calhoun concluded that the mice could not deal effectively with repeated contact from so many. individuals the evidence of violence increased to the point where most individuals had their tails bitten off to some extent, eventually the entire mouse population perished. Dr. Calhoun's

experiment

is a classic example of a typical population and its growth when uncontrolled. Research in this area continues under his direction. currently supervising Dr. James Hill has taken the basics of Calhon's experiment to study social behavior even more closely in his experiment he uses rats instead of mice he selects healthy individual tools to start the population he anesthetizes the rats so that they Dr.

Hill can perform a small test operation necessary for the success of his experiments. A small encapsulated electromagnetic device is implanted in each rat. This small unit allows sensor devices to track the movement and position of each individual in the population after After surgery the rats are introduced to their new multiple levels at home, all at the same time, the rats immediately begin to explore their new environment before organizing territories and nesting. Dr. Hill will track how individuals move in crowded situations. This movement is tracked by tubular sensing devices each time a rat enters or passes through a tube. the unit detects and records their presence this constant movement is monitored by computer nesting activity is also studied Dr.

Hill has observed that the larger the population, the less care a mother gives to her nest and her young the same type of individuals that resulted in the mouse utopia are also emerging in the rat population, there are aggressive and outcast asocials, although these studies use animals, findings on population growth and individual behavior are being closely compared to our own human population, like all populations that have existed on this planet, many researchers believe that the human race has reached a crucial point in the exploitation phase, a point at which important decisions must be made and careful planning must be implemented if we want to survive.

Studying plant and animal populations helps us make decisions about the future of our human population so that we can maintain our own balance with nature.