Boreskov

PL‐5ON THE COMPLEXITY OF PRIMORDIAL BIOLOGICAL OBJECTSZhuravlev Yu.N.Institute of Biology and Soil Science, Russian Academy of Sciences, Far Eastern Branch,100‐letya, 159, Vladivostok 690022, Russia; zhuravlev@ibss.dvo.ruThe pioneering paper of Kolmogorov (1965) had opened the way to compare thecomplexity of two objects (or of their states) represented as finite strings (sequences). Aftersignificant contributions of Chaitin, Solomonoff, Gacs, Li, Vitanyi, and some others, a veryclose connection between complexity and information content of objects was revealed. Wesuppose here that the notion of complexity in biological world is differentiated, and that thedevelopmental and evolutionary dynamics of types of complexity can be effectively used tocharacterize the period of transition from chemical evolution to biological one.To use this idea at the reconstruction of the properties of the systems operating duringthe transition period, we need to define two classes of primordial biological objects. In thefirst class we include the objects on the earliest stage of their individual development likespores, zygotes and so on. In the second class we combine the objects of the “simplest”organization like viruses, mycoplasmas, small bacteria. Comparative analysis of complexity ofthese objects and their more advanced counterparts can give the new knowledge aboutevolution of complexity in the course of making of biological world.Following the definition of biological object [1], there are two main representations ofbiological object – internal and external ones. Accordingly, the complexity of anyconditionally singled‐out biological object can be roughly understood as a sum of two typesof complexities. First type is a part of classic Kolmogorov‐Chaitin‐Solomonoff (KCS)complexity which, in general case, is an objective measure for the information in a singleobject [2]. Here we investigate a part of KCS complexity (KCS’), which reflects theinformation transformation in the course of becoming of the object (complexity of internalmaps from a germ cell up to the daughter germ cell). This complexity we associate here withthe states of chromatin.The context‐dependent complexity reflects the relations of object with surroundings; itis a complexity of external maps. This complexity we associate with the states of phenotypein the classic representation of phenotype via observables. The complexity of this plane is acomplexity of multiple of finite binary strings, whereas the multiple can be interpreted as aset or as a list of strings (with different calculus implied [2,3]). In spite of striking differencebetween these two types of complexity considered here, the general idea that the13