![]() ![]() The main points of interest for me were how poor a prediction of future technology it was, and how badly sci-fi was written 55 years ago. My copy comes from the late 80s when it was selling very well. First in a successful and long running series. Pulp sci-fi written in 1961 and reprinted dozens of times. ![]() ![]() The Stainless Steel universe has the 'standard' many-times-faster-than-light travel, instant communication (via psychic telephone men this time), and highly This was an interesting book to read. (2013).This was an interesting book to read. Nuclear Gene Variation in Wild Brown Rats. W., Zhang, Y.-H., Cong, L., Wang, Y., Zhang, J.-X., & Keightley, P. There were no black rats, mole rats, or any other kinds of rat used. Therefore, apart from the fact that the article was discussing data on a domesticated albino strain of the Norway rat, all the experiments mentioned used brown rats. 2012), no matter where in the world you collect them (Ness, 2013). There is very little genetic variation in brown rats (Ness, et al. In each case my associates and I maintained close surveillance of the colonies for 16 months in order to obtain detailed records of the modifications of behavior induced by population density. Each was permitted to increase to approximately twice the number that my experience had indicated could occupy the available space with only moderate stress from social interaction. The data for the present discussion come from the histories of six different populations. ![]() Then he turned to a domesticated albino strain of the Norway rat under more controlled circumstances indoors, and Even with only 150 adults in the enclosure, stress from social interaction led to such disruption of maternal behavior that few young survived. The reason this larger population did not materialize was that infant mortality was extremely high. Yet adult mortality was so low that 5,000 adults might have been expected from the observed reproductive rate. By the end of 27 months the population had become stabilized at 150 adults. There could be no escape from the behavioral consequences of rising population density. 'With an abundance of food and places to live and with predation and disease eliminated or minimized, only the animals' behavior with respect to one another remained as a factor that might affect the increase in their number. I confined a population of wild Norway rats in a quarter-acre enclosure. Reading the article you mentioned, Calhoun (1962) started with wild Norway Rats, also referred to as common rats, brown rats, street rats, sewer rats, or Hanover rats. No, Calhoon did not account for genetic diversity in his experiments outlined in your question. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |