Dep. Zoology of Invertebrate, Biological Faculty, M. V. Lomonosov Moscow University. Vorob'evy Gory.Moscow 119899. Russia

Abstract

The ideas of "modular organization", "modular growth" and "modularity" were introduced byzoologists (Finsk, 1973; Rosen 1979; Chapman, Stebbing, 1980) and botanists (Harper, Bell, 1979) todescribe similar peculiarities of life strategies of colonial invertebrate and multicellular plant organisms.The acceptance of new terminology was an attempt to analyse similarity between non-relatedsystematically organisms beyond the frames of traditional approach of comparative anatomy based onhomologization. Modular concept contributes to new approach based not on the taxonomicrelationships, but on the system features of organization and development. The basis of modular structureis the repeated morphogenesis but not peculiarities of structural units of organism. The possibility ofnumerous reproductions of stereotype of development, being a fundamental character of all organisms.manifests itself as: 1) sex reproduction, 2) asexual reproduction. 3) modular growth, 4) polymerization ofhomological parts. Modular structure differs from others in: 1) multiplication of all structural elements, connected with each other, 2) numerous places for a food entrance, 3) the absence of central regulation ofvital activity, 4) flexibility of organism's shape that is not so strictly restrained genetically as in case ofunitary organism. Because of these peculiarities modular organisms are able to use efficiently highlyheterogenic habitats that is very important for sedentary organisms. It is assumed that modularorganization has some physiological properties, e.g. the possibility to accumulate food resources toprovide the metabolism in the most important part of an organism. Modular life strategy results also inreduction of intraspecific competition since the number of genetically independent individuals isdecreasing.