In The Origin of Species, Darwin argues that environmental factors have the power to change and shape species into new forms. For Darwin, physical isolation and continuum both play critical roles in the construction of species. Isolation “is an important element in the process of natural selection” (149*) because isolated areas have uniform conditions (and so all members of a species are pushed to adapt in the same way), intercrosses with other varieties are stopped, and better adapted organisms (which might fill available niches before other species could adapt) are also prevented from migrating. Yet “largeness of area is of more importance” (150), because the increased competition ensures that species will be driven to adapt or perish. Even in large areas, the “good effects of isolation will generally, to a certain extent, have concurred” (151) due to “oscillations of level” (151) that create periodic isolation. Thus, the method of species formation and the kind of species which are formed are heavily dependent on spatial configurations.
Social configurations can also play a role in isolating a variety from—or exposing it to—other varieties. Within large areas, isolation can be created due to varieties of one species “haunting different stations,” “breeding at slightly different seasons,” and “from varieties of the same kind preferring to pair together” (149). Continuous spaces can be divided to create isolated space, and ultimately it is this interplay between continuum and isolation (made from continuum) that propels the formation of species as animals are in turn sheltered from and exposed to those who could fill a similar niche. Both the physical and social environments of a given species contribute to what the species will become or give rise to—the specific physical and social arrangements matter, and they construct what the natural and the cultural can become.
The specific physical and social arrangements give rise to new species, and these species are characterized by isolation and continuum. Darwin’s taxonomical diagram makes clear the interrelatedness of all species; any species (or individual) can be traced to another through a continuum of relatives, even though the number of relatives may be vast. Simultaneous with this continuum is the isolation that forms as a species “press[es] hardest on its nearest kindred, and tend[s] to exterminate them” (154), ultimately leaving each species to stand alone. Humankind is separated from chimpanzees, but only because all “the intermediates between humans and chimps are all dead” (Dawkins 263**). The non-human animal is both like and unlike the human animal due to the history of physical and cultural arrangements that have become enfolded or sedimented in our DNA and our bodies. This sedimentation occurs literally in the geological record:
In the diagram, each horizontal line has hitherto been supposed to represent a thousand generations, but each may represent a million or hundred million generations, and likewise a section of the successive strata of the earth’s crust including extinct remains. (167)
Upon an initial viewing of Darwin’s diagram, it may appear upside down, in that time progresses from the bottom to the top of the page, but Darwin has done this purposefully so that the diagram functions on two levels: as an image of an abstract, discursively constructed species space and as an image of a concrete, materially constructed geological space. Niches in the economy of nature become branches on the taxonomical tree which in turn become fossilized records in a breathtaking move from the natural to the cultural and back again.
But to divide the natural from the cultural misses Darwin’s argument, or at least misses what is implicit in the argument: the physical and the social, the natural and the cultural, and the material and the discursive (or even the ideas of species and variety) are not hard dualities. They are part of continuums and can only be isolated from one another under specific arrangements that place a cut between them.***
*My edition of The Origin of Species is the older Penguin edition. Subtracting 50 from my page numbers should get you to the approximate location in the new Penguin edition (may have to go a page back or forward).
**Dawkins quote from The Blind Watchmaker.
***Monumental debt owed to Karen Barad for ideas about the material-discursive.
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