Harvard University The Arnold Arboretum of Harvard University
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Constantine Rafinesque (1783-1840)

The truth is that Species and perhaps Genera also, are forming in organized beings by gradual deviations of shapes, forms and organs, taking place in the lapse of time. There is a tendency to deviations and mutations through plants and animals by gradual steps at remote irregular periods. This is a part of the great universal law of PERPETUAL MUTABILITY in everything. Thus it is needless to dispute and differ about new G. [genera] Sp. [species] and varieties. Every variety is a deviation which becomes a Sp. As soon as it is permanent by reproduction. Deviations in essential organs may thus gradually become new G.” (Rafinesque, “Principle of the Philosophy of New Genera and New Species of Plants and Animals”, 1833).

In 1841, the American botanist Asa Gray authored a “Notice of the Botanical Writings of the Late C.S. Rafinesque.” Regrettably for Rafinesque, Gray was no fan of his voluminous additions to the number of plant taxa that were previously recognized as species by botanists.  In his lifetime, Rafinesque would go on to name more plant species than even Linnaeus.  Gray wrote,  “According to his principles, this business of establishing new genera and species will be endless; for he insists… that both new species and new genera are continually produced by the deviation of existing forms, which at length give rise to new species… He assumes thirty to one hundred years as the average time required for the production of a new species, and five hundred to one thousand years for a new genus… (238, American Journal of Science and the Arts, 1841).

Rafinesque’s ideas on the variation of botanical form were inseparable from both his evolutionary theory and his botanical methods. In 1833, he published, “Principle of the Philosophy of New Genera and New Species of Plants and Animals”, containing excerpts of a letter he had written to the botanist John Torrey, in his own Atlantic Journal, and Friend of Knowledge to advance his opinions that recognition of the “great universal law of Perpetual mutability” implied a change in classificatory practice among professional botanists. He proposed that the “tendency to deviations and mutations through plants and animals by gradual steps at remote irregular periods” would allow observers of the natural world to trace each species or variety back to its primitive original, therefore creating a new “natural” genealogical method of classification and condensing and simplifying extant classificatory systems (1833, 1836).

If it is inescapably true that in every small variant of nature, Rafinesque saw the potential makings of a new species, it is also true that this world view represented the antithesis of the dominant views of most classifiers and taxonomists, who insisted – at least for purposes of their science – that species were eternally unchanging. “Nature only acknowledges individuals, and varies them constantly; so as to produce new species now and then…” (The World, 1836) Rafinesque had a keen awareness of variation within species, and understood that such variation was the raw material of evolution.

“The process is by the seedlings being somewhat different from the parents, and thus evincing a deviation of typical mould, that may be, or may not be; propagated again. If it is, this soon assumes a permanence, becoming a permanent variety if the deviation is slight, such as mere color of flowers, size of stem, leaves, &c.; but becoming a New Species! if at last several deviations are permanently combined. A tendency to such deviations is sometimes met even in the various annual shoots of the perennial plants, or shrubs and trees, that are not always alike to those of the preceding years.” (16, New Flora and Botany of North America, 1836)

What is clear in Rafinesque’s transmutationist writings is that he did not view all of life as descended from a single common ancestor. “All species may have been varieties once, except the original types or ancestors of the genus…”; a failing that was noted in Darwin’s Historical Sketch. Thus, in a manner reminiscent of the eminent plant hybridizer William Herbert, Rafinesque could envision the evolution of new species but could not imagine scaling this common process to all of life.

“We know not how many living forms existed at first, or were created on earth at the earliest period; but by the fossil relics of many, we ascertain that they were fewer and often different. Whatever was their original number and types; it is probable that these primitive individuals have produced all the actual various species, of which we have already ascertained nearly eighty thousand of animals, with a hundred and twenty thousand of plants. The proofs of this fact are found in the varieties and monstruosities, still proceeding under our eyes, or that have for ages past. Every species was once a variety, and every variety is the embryo of a new species.” (The World, 1836)

Also like Herbert, Rafinesque wrote a lengthy poem that included the topic of mutability in the natural world. In The World, or Instability (1836), his ideas on evolution in nature are placed in the context of his philosophical view of a Hericlitean world. This poem also strongly echoes Erasmus Darwin’s posthumously published Temple of Nature (1803).  Advocating for an eternal law of constant change which causes deviations in the form of living beings, including plants, he writes:

“…CHANGE extends also to vary forms,

…Not even two leaves or blooms

In vain you’ll seek to match upon a tree.

…This is the Law, the positive decree…” (14-15, Worlds, 1836).

Complicating Rafinesque’s supposedly simpler method of classification was the fact that he believed each new form should be given a new name. This propensity for “multiply[ing] names” upset many of his botanical contemporaries who, like Gray, disregarded much of Rafinesque’s work during his lifetime. Nevertheless, Rafinesque’s existing publications show him to have been a polyglot who published on a multitude of topics including botany, zoology, and linguistics. Despite being denied a position on the Lewis and Clark expedition of 1806, Rafinesque individually surveyed much of the southern and central North American flora. He was appointed a professorship at Transylvanian University in Kentucky in 1819, but left over disagreements with the administration.