lecl@quads.uchicago.edu (elizabeth e. leclair) (06/01/91)
In article <squirrel.675655385@behind> squirrel@behind.caltech.edu (Patricia M. White) writes: > >I'm not a taxonomist, but it seems to me that a colony is a group of organisms that >can survive if you disassociate them into their respective parts, whereas an >animal dies if you dissect it. > "Colony" is probably one of the most abused words in biology. Just think: --ant colonies --bryozoan colonies --hydrozoan colonies In the first case, "colony" is the catch-word for a collection of individuals, who are obviously separate entities and can survive apart from one another, but which live and "work" in some communal fashion. Members of the colony are genetically related to each other, although at different levels, and almost none of them are reproductively active. A bryozoan colony (a little mat of polyps, someimes in rigid cells) is largely a repetition of clones whch bud off from the sides of the colony so that the wh ole thing grows like a mat. All the organisms share certain coelomic spaces and maybe a common digestive tract, but if you break it up the pieces can often survive in other places. A hydrozoan colony like the Portuguese man-of-war is similar, except that certain polpys are specialized to do certain jobs: the stinging cells, the float, etc. These parts are not autonomous and cannot survive if separated. Yet all are called "colonies." I read an interesting article (forgotten where, of course) about the roots of the word "colony" in biology as derived from "colonalism" as applied to world powers, i.e. "Britain rules the waves." In the meantime, I would suggest never ascribing any sort of technical definition to the word "colony." Use and interpret it only casually, lest you be ensnared in generalizing over a whole mess of organism/part relationships in nature whic deserve individual consideration. -- ~~~~~~~~~~~~~~~~~ Elizabeth E. LeClair [lecl@midway.uchicago.edu] ~~~~~~~~~~~~ "Sex is two wavy lines, and the United States of America is a trapezoid." Claimer: These are my opinions and no one else can claim them! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~