Barnacles, God, & Catastrophism

Barnacles, in all their curl-footed encrusted glory, may be further from most things on a spectrum measuring drama. The drama they do mark is the beginning of a series of correspondences during the late nineteenth century between two prominent naturalists: Yale geologist-invertebrate zoology affiliate James Dwight Dana and Charles Darwin.

YPM barnacle specimens collected by Dana

Dana and Darwin weren't unaware of each other as naturalists. Dana, a renowned geologist, participated in worldwide expeditions like the 1838-42 U.S. Exploring Expedition. Many of Dana's collected specimens are in the Peabody IZ collections. Darwin was known as one of England's most prominent naturalists, and of course, founder of the theory of evolution—a fresh and contentious topic then.

James Dwight Dana
(Wikipedia Commons)

Charles Darwin
(Wikipedia Commons)

Dana and Darwin's regular correspondences began in 1849, opening with a request by Darwin for Dana's Cirripedia (barnacle class) specimens. Darwin was working on an "anatomical and systemic monograph on the Cirripedia" and wanted to compare the Cirripedia specimens Dana had collected from the U.S. Exploring Expedition with other borrowed specimens.

Transcribed letter from Darwin to Dana. August 12th, 1849
(Yale Manuscripts & Archives)

In the correspondences that follow, Darwin and Dana discuss a range of topics: more on Darwin's Cirripedia work, coral reefs, Dana's crustacea book. Darwin saw a lot of commonalities between Dana's observations of volcanic geology in Hawaii and his own observations of eruption on the Galapagos. But Dana didn't wholly accept Darwin's theory of evolution, revealed by the letters that Darwin sent regarding Dana's objection to species having the ability to change (despite not having read Darwin's book yet).

Transcribed letter from Darwin to Dana. September 17th, 1853
(Yale Manuscripts & Archives)

The struggle to reconcile evolution with natural history was a common challenge in the nineteenth century. Many other naturalists, such as Harvard zoologist Louis Agassiz, saw specimens collected on expeditions as an illustration of divine intervention in the adaptations of plants and animals to their environmental conditions. Dana himself was born into a religiously devout family. 

Dana had three main issues with evolution heavily rooted in limitations of the geologic record: 

1. The geologic record tended to show complete shifts in development in species, as opposed to transitions between species. (physical transitional evidence was still lacking at the time)
2. Sometimes higher forms of species preceded lower forms of species in the geologic record. This observation weighted against the notion of linear development that evolution suggested. 
3. Parts of the geologic record appeared to mark mass extinction events, followed by the re-instatement of life. 

Dana's geological observations aligned better with catastrophism, the Biblical creation of all living creatures by God through a series of creations that were punctuated by catastrophes—typically floods—that explained extinction events. A fascinating aspect of Dana's belief in catastrophism was his simultaneous belief in uniformitarianism, a central concept to explaining geological change over thousands of years through natural processes like erosion, as opposed to periodic natural disasters. Dana reconciled the two principles by distinguishing organic change from inorganic change. By reserving inorganic change for uniformitarianism, Dana didn't have to subscribe to belief in a young Earth, and could explain sudden shifts in species evident in the geologic record via catastrophism. Ultimately, Dana believed in the permanent immutability, or inability to change, of species. 

Though Darwin continued to gain confidence from the support he was received from the scientific community for his theory, Darwin didn't blame Dana for his hesitation, even empathizing with his doubts. "Indeed, I should not much value any sudden conversion, for I remember well how many years I fought against my present belief." he concludes in a letter to Dana. 

Transcribed letter from Darwin to Dana. September 17th, 1853
(Yale Manuscripts & Archives)

Over the years, Dana gradually came to accept more tenants of evolution. His manuscript, "On Cephalization" (1876), applied the concept of natural selection, though didn't see it as the primary force behind evolution like Darwin. Another appealing aspect of evolution was the "survival of the fittest" doctrine. Dana's use of it to explain the "inferior cephalization" of native peoples he encountered on expedition is part of the broader sociological implications of the theory of evolution that justified imperialism during the time. 

Above all, Dana never strayed from emphasizing God's efficacy in nature, thus incorporating evolution into part of God's design in nature. His struggle to reconcile science and religion, as well as science and society, show that elements of a scientific theory can be cherry-picked to one's one beliefs—for better or for worse. What one theory proves can be adapted for many justifications beyond the realm of science. 

For further reading on Dana's relationship to Darwinism, read this comprehensive article by historian William F. Sanford, Jr.