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from the subatomic particles to the universe galaxies. This duality is conjugated by
the tendency toward the complexity of forms. In fact, the main seven functions of
Table 4.4, which refer to cells, occur recurrently, and the same game of life starts
again for complex organisms, plants, animals, and animal populations. At the end of
a level of biological organization, new entities emerge which are the starting point of
a further application of the same paradigm. This schema explains the logic underly-
ing a lot of phenomena, going from morphogenesis, speciation, and sexual mating.
These seven steps are basilar in the construction of living individualities, but they
are always immersed in contexts of a population dynamics, where individualities de-
fine specific roles of interaction, cooperation, and competition. For any individual,
the acquisition of the abilities of Table 4.4 is realized with conflicts, and individ-
ual death is an existential necessity. Paradoxically, death which is the antithesis of
individual lives, is the key of the natural selection applied to populations.
Ta b l e 4 . 4
Seven basic functions of living organisms
Nutrition (environment resource acquisition)
Ingestion/digestion (acquired resource transformation)
Movement/autonomy (territory navigation and control)
Respiration (energy acquisition and transformation)
Differentiation (function specialization)
Morphogenesis (form acquisition)
Reproduction (heredity and replication)
Let us explain, in more details, the seven musts of Table 4.4 from an evolutive
point of view. Of course, without taking matter from outside, no cell can survive.
The first form of nutrient acquisition was possible in the surroundings of such nu-
trients. However, very often they were available where also enzymes were present
which were able to produce them from some substances. Therefore, a natural pas-
sage to a more efficient form of nutrient acquisition was the ability of cells to acquire
these enzymes in order to catch directly substances and to transform them internally.
This ability surely provided a great advantage, by removing the necessity of
remaining near to nutrients and enzymes (in the case of heterotrophs), or of di-
rectly depending on the fluctuations of nutrient concentrations (in the case of au-
totrophs). In this way, (heterotroph) cells became open to a space exploration ca-
pacity; therefore this was the prerequisite for developing movement functionalities.
From a “technical” point of view, the ingestion and digestion abilities require com-
plex topological skills of membrane manipulations. In fact, the predation of small
molecules can be obtained by channel mechanisms. But, for catching big molecules
(or other cells), more dramatic methods need to be elaborated. This happens when
a membrane realizes
invagination
and
phagocytosis
. In invagination, a part of a
cell surface forms a concavity where an external body can be wrapped in order to
