X.3.1.2 Microspheres exhibit enzymatic activity but not reproduction and heredity, and can thus not become the subject of biological evolution

The microsphere hypothesis attempts to resolve the aspect of formation of molecules with enzymatic activity and thus the evolution of primitive metabolism.Heating a mixture of aminoacids in anhydrous medium leads to their condensation into an irregular polymer, a proteinoid, which has random sequence and only reflects the contents of the individual aminoacids in the original mixture.Following dissolution in water, these proteinoids form tiny, spherical, sometimes hollow species, microspheres (Muller-Herold & Nickel 1994)(Fig. X.3).Microspheresdo not exhibit properties such as growth and reproduction and are not separated from the environment by a membrane.However, it has been demonstrated that they exhibit a number of kinds of catalytic activity (Fig. X.4).The formation of proteinoids is an approximation to a

 

Fig. X.4. Catalytic activity of proteinoids. The graph shows the course of decarboxylation of pyruvate in the presence of proteinoids (black points), in the presence of unpolymerized aminoacids (grey points) and without any catalyst (empty points). According to Fox and Dose (1972).

possible mechanism of the formation of the first enzymes and thus the first building blocks of future metabolism; however, it tells us very little about the mechanism of formation of systems capable of biological evolution.

Was this information useful for you?
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.