Carl von Linné, or Linneus, who was born in 1707, noticed that biological organisms can be classified, as had Aristotle. His contribution to science was a formal understanding of the a hierarchy of classification. Much of the subtle variations between the finer distinctions of creatures are done on shape, form and feature. Some classifications are general, and hold many types of organisms. Other types of classifications are more specific, and hold only a few.
One interesting observation is that almost all of the latter, specific types of classifications hold organisms which are also member of the same more general classes. In other words, there are different types of geese, but all geese are birds.
This observation is so familiar that it seems uninteresting. Of course, geese are birds! What else could they be? But Steven Jay Gould noted the convergence of similar functional equivalents among fairly unrelated species, such as the panda and the humanoid apes, which have opposable thumbs to grasp things in a pincer grasp. Almost none of the creatures in the taxonomic spectrum between humans and pandas demonstrate that capacity, although they have the generic developmental form of the upper extremity which allows such a grasp to be developed.
The genetics of Gregor Mendel and all to this day demonstrate the hereditability of phenotypes that affect form, structure and such observables in the organism. We have come to understand that these things inherit stably. We have also come to assume the nature of the canvas upon which these genetic forms and structures are laid – the organism itself.
We know that peas, for instance, inherited for Mendel as smooth or wrinkled, green or yellow. But why are organisms so conditioned and structured to demonstrate phenoypes in a widely variant form, from a paucity of gene differences?
It is tempting to restate the tautology of evolution – that things are this way because evolution necessarily has made them so. Although the tautology is impressive, it is meaningless, really. Clever opponents of evolution have pointed out the meaninglessness of the tautology. It is important to avoid it here, as it can dull the argument.
Why are organisms so expressive of phenotype? From molecular biology, it is not obvious. For the prokaryotes, especially the archaebacteria, there are many metabolic pathways which allow the utilization of a number of chemicals as energy harvesting, as well as electron transfer participants – the two most important aspects of life.
But their external phenotypes seem fairly uninteresting. Thermophilic bacteria, for instance, have characteristics that keep the proteins from denaturing in high heat, et cetera. But prokaryotic beasts generally look like bacteria all over – a handful of forms, a handful of structures.
Tigers have stripes. Zebras have stripes. These are impressive phenotypes. Why does their canvas – their species – allow for such radical expressions of form not seen in the lion nor horse?
It does not invoke that tautology to say that most of the fine variation of the categories assigned by Linneus, genus and species and such, are often structurally trivial and biochemically incidental. They change growth and form, such as seen in D’Arcy Thompson’s interests, proportion and other observables.
Variation among humans is quite genetically trivial. We are not speciated; we’re far too recently disseminated from common ancestry. Yet we think we differ widely. Why?
One single-gene change has made for extensive perception of phenotypic variation – the white gene, or the inactivity of the constitutive melanin gene. It seems to span a broad range, from the near-albinism of Scandinavia to the very dark phenotypes in Africa. We certainly LOOK different – and that seems to be an important element of speciation.
I have argued before, and will not demonstrate here, but humans vary widely and rapidly in their phenotypes of facial form, ways widely perceptible and recognizable – even though they are genetically trivial. We can see a Korean face, a Japanese face, an Indian face, New World and Old. These observations mean nothing scientifically, but their observable certainty by humans is remarkable. Remember, our companions the dogs are astute observers of human expression. Can they tell “phenotype?” I wonder.
Interspecies sex is rude, disgusting – and fruitless. The method of reproduction seen all over the eukaryotic kingdoms does not favor extensive genetic interplay between disparate organisms. Something about chromosomal organization favors the development of species that are sterile to the exchange of interspecies genes. We seem to have reserved our clan taboo to race – that seems to be a human habit worth remarking on.
To summarize the important points, and sprinkle in a few not developed:
- Genetics of form and recognizable similarity and difference comprises most of the trivial set of Linnean classes.
- The palette of species favors expressive variation, as opposed to, say, biochemical variation, which is more likely to be disadvantageous.
- Yet these classes are infertile to interbreeding.
- Therefore, genetics tends to serve the purpose of genetic sequestration of trivially differing groups.
- “Race” is a scientific illusion – a trivial class difference between interbreeding members of the same species.
- Humans tend to “racialize” within our species due to elements which are phenotypically variant but genetically trivial.
- The paradox of race is that it is a meaningless characteristic that most humans can recognize.
- It is our capacity to recognize difference that is inherent in Homo sapiens as opposed to other animals. That has controlled, driven and predominated in our society, and may lead us ultimately to our extinction if we do not master it.