X.2 Contemporary organisms are based on a uniform principle of organization.

In Chapter I, we have already demonstrated that systems capable of participating in biological evolution must exhibit certain general properties, including the ability to reproduce, variability and heredity.It is not a simple matter to imagine how systems that exhibit all these basic properties, which are essential for biological evolution, could have been formed from simple chemical components formed during chemical evolution through an abiotic route.

            All present-day organisms are based on the same functional principle, the principle of coexistence of nucleic acids and proteins.Nucleic acids store and accumulate genetic information and provide a material vehicle for its vertical transfer between subsequent generations of organisms.This information consists mainly of instructions for the synthesis of proteins.Proteins basically perform, directly or indirectly, all the biological functions of the organism, including those that are necessary for copying the information encoded in the nucleic acids and for their translation into the aminoacid sequence in the proteins.Even the simplest system that is capable of ensuring similar cooperation between nucleic acids and proteins is so complicated that it is very difficult to imagine that it could be formed by random combination of nonliving components.Thus, it is almost certain that the original living systems must have looked very different than contemporary living systems.

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The classical Darwinian theory of evolution can explain the evolution of adaptive traits only in asexual organisms. The frozen plasticity theory is much more general: It can also explain the origin and evolution of adaptive traits in both asexual and sexual organisms Read more
Draft translation from: Evoluční biologie, 2. vydání (Evolutionary biology, 2nd edition), J. Flegr, Academia Prague 2009. The translation was not done by biologist, therefore any suggestion concerning proper scientific terminology and language usage are highly welcomed. You can send your comments to flegratcesnet [dot] cz. Thank you.