Information Technology Reference
In-Depth Information
Einstein said, God does not plays dice, but surely Nature does it. Evolutionary dice
are Mutation and Recombination, they are the tools for exploring biological possi-
bilities. These two golden rules can be implemented in many ways, for example, by
replication errors and by sexual mating. However, what is revolutionary in Darwin's
approach is that the free creative role of chance transforms a feature of individual
continuity into a source of innovation for species. By reversing Lamark's perspec-
tive, Darwin disregards any passage from the individual biological experience, to
the species. The biological memory gained by the species passes to the individuals
(by means of genomes, in modern terms), but the reverse does not apply. This means
that if one animal acquires a long neck by trying to eat the best leaves, which reside
on the top of some high tree, then this character does not pass to his offspring, un-
less it is written in his biological memory since his birth. In fact, the giraffe got a
long neck not because of the attempts he or his parents made, but on the contrary,
the long neck occurred, by chance, in his genetic characters, and for this reason this
animal had a better chance of surviving in places where high trees (with good leaves
on the top) are more available than other kinds of vegetable foods.
Species are abstract entities which extract biological population characters
present in reproductive lineages. They are archetypal forms of life, which are sub-
jected to their own dynamical laws, Species originate when a sufficient number of
characters is cumulated (a clear understanding of what sufficient means, is matter of
investigation), which determines a reproductive lineage which separates it from the
lineage where it occurs. It is very difficult to find rigorous definitions and models
of these intuitions. From Linnaeus's approach to the classification of living organ-
isms, to the modern molecular approach based on genome sequencing, and to the
recent proposals of genetic barcoding, enormous problems remain for a clear un-
derstanding of the relationship between individuals and species. Perhaps, a better
solution to this problem has to cope with more complex relations of membership
between instances and genera, within a gamma of levels, where sharp and univo-
cal classifications need to be abandoned. This is, in many aspects, a mathematical
and computational problem, where phylogenetic distances, clustering of strings, se-
quence fingerprints, and genomic informational indexes could be applied in very
specific and sophisticated ways.
4.7
Time's Arrow and Complexity
Time is experienced directly by living organisms as the dimension along which
life dynamics develops with an evident irreversible character. A life starts with a
birth and ends with a death. Maybe humans are the only living organisms with
a clear awareness of this, but no living organism can escape this law. Life flows
along a direction going from birth to death and all life events are arranged in this
order. This notion of time is postulated by Darwin's evolution theory and, along
the course of time, life follows a process going from the appearance of a prebiotic
stage to the complex multicellular organisms, and to the complex societies of human
