ScienceDaily (Dec. 4, 2009) — Rice University evolutionary biologists David Queller and Joan Strassmann argue in a new paper that high cooperation and low conflict between components, from the genetic level on up, give a living thing its "organismality," whether that thing is an animal, a plant, a bacteria -- or a colony.
Some of the traits scientists use to describe an organism, such as individuality or even membership in the same species, may not be necessary to achieve organismality. What is necessary, they argue, is a commonality of interests and minimal conflict that when combined, makes this the premier level of adaptation.
Beached Portuguese man-of-war. On the level of groups of multicellular individuals, the Portuguese man-of-war is a paragon of organismality. Technically a colony of sea-going polyps, each polyp seems to know its place, taking on a specialized duty that contributes to the survival of the whole. (Credit: iStockphoto/Brad Wieland)
Queller and Strassmann, the Harry C. and Olga K. Wiess Professors of Ecology and Evolutionary Biology, address what they call "the truly central questions about the organization of life" in a new article recently published in the Philosophical Transactions of The Royal Society Biological Sciences.
"This is more than a semantic game of deciding that X is an organism and Y is not," they wrote. "The scientific community could choose any name they want for entities with extensive cooperation and very little conflict, but the existence of such entities is one of the striking features of life, and explaining how they evolve should therefore be an important task."
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Beyond society: the evolution of organismality
David C. Queller* and Joan E. Strassmann
- Author Affiliations
Department of Ecology and Evolutionary Biology, Rice University, 6100 Main Street, Houston, TX 777005, USA
* Author for correspondence (queller@rice.edu).
Abstract
The evolution of organismality is a social process. All organisms originated from groups of simpler units that now show high cooperation among the parts and are nearly free of conflicts. We suggest that this near-unanimous cooperation be taken as the defining trait of organisms. Consistency then requires that we accept some unconventional organisms, including some social insect colonies, some microbial groups and viruses, a few sexual partnerships and a number of mutualistic associations. Whether we call these organisms or not, a major task is to explain such cooperative entities, and our survey suggests that many of the traits commonly used to define organisms are not essential. These non-essential traits include physical contiguity, indivisibility, clonality or high relatedness, development from a single cell, short-term and long-term genetic cotransmission, germ–soma separation and membership in the same species.
organism organismality individuality social evolution cooperation conflict
Footnotes
One contribution of 16 to a Discussion Meeting Issue ‘The evolution of society’.
© 2009 The Royal Society
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