Geoscience Reference
In-Depth Information
corresponds to the category of “an area of study”, generally
a characteristic of an academic field. This might be a cell for a
cytologist, a multicellular organism for a physiologist, a population or
settlement for a population biologist, the ecosystem for an ecologist,
the society for a sociologist or for an economist, the area beneath
the Earth's surface for a tectonician or volcanologist, the Earth's
surface and atmosphere for a climatologist or an oceanographer, etc.
For the non-scientific observer, the intuitive grouping is that which
corresponds best to a visual entity, whether that be observed by
eyesight alone or through images furnished by means of modern
technology (from the microscope that allows cells to be seen to
satellites that allow the Earth to be seen from space). It is not
surprising that the disciplines in the natural sciences, for the most part,
are derived from the visual perceptions of the “man on the street” and
from technological progress.
The arbitrary identity of a system, through a grouping, is therefore
a form of categorization of the type that biologists use for very broad
families of life forms (e.g. bacteria and archaea, protist eukaryotes,
multicellular or metazoan eukaryotes). We note, however, that this is
different from phylogenetic categorization (modern day taxonomy), as
this is founded upon similarities in the attributes and in the genetic
proximity amongst a range of objects: that of individual living beings.
In the case of a living being, the definition is, in general, relevant
because of its physical limits (e.g. cuticles and skin) and its autonomy.
Note that the idea of autonomy can after all be very weak. Is an ant
autonomous without its anthill? Is a cell autonomous in a multicellular
organism? Is a man or woman autonomous on a reproductive level?
The definition of a system is, in retrospect, very arbitrary when the
proportion of non-living components of the system is important (e.g.
ecosystems and societies). Such a system should therefore be the
subject of a precise and rigorous description within the framework of
the limits that have been arbitrarily fixed upon it. Too often, the notion
of an ecosystem is, unfortunately, employed as a generalization, each
user implicitly conferring a different typology on it.
