Friday Fossil Feature – Happy Darwin Day!

By Sarah Boessenecker (@tetrameryx)

Happy Fossil Friday, and Happy Darwin Day!

For today’s Friday Fossil Feature, we’ll look into barnacles – why? Barnacles were important to Darwin in his research and writing of On the Origin of Species.

Giant barnacle-encrusted scallop. From CCNHM Collections, photo by S. Boessenecker.

Giant barnacle-encrusted scallop. From CCNHM Collections, photo by S. Boessenecker.

Chesapectin septenarius (scallop) with barnacles.  From CCNHM Collections, photo by S. Boessenecker.

Chesapectin septenarius (scallop) with barnacles. From CCNHM Collections, photo by S. Boessenecker.

Darwin had previously studied marine invertebrates at the University of Edinburgh, under the guidance of Robert Edmond Grant, and collected a number of barnacle specimens while voyaging with the HMS Beagle.

After his return to England, he began dissecting the barnacle specimens, while compiling his ideas about natural selection, thinking back on the strange fauna he had noted during his time in the Galápagos. Darwin worked closely during this time with Joseph Hooker, and the two compared Darwin’s specimens with those borrowed from other institutions. Barnacles had recently been discovered to be crustaceans rather than molluscs, and Darwin noted the many homologies with other crustaceans. Hooker argued that these homologies were “archetypes” from the Divine mind, but Darwin felt they instead showed evidence of Descent through time, or natural selection. Darwin saw these homologies as irrefutable proof of adaptations, as organs changed over time to work under new conditions.

Darwin's barnacle collection, now at the Zoological Museum of Copenhagen. Image from WikimediaCommons.

Darwin’s barnacle collection, now at the Zoological Museum of Copenhagen. Image from WikimediaCommons.

As Darwin continued to work on these specimens, he was constantly working on his theory, ironing out details and nuance. Once his volumes on barnacles were published, he was able to devote his full attention to writing what is arguably the one of the most celebrated ideas in science to this day.

 

Further Reading:

Browne, E. Janet (1995). Charles Darwin: vol. 1 Voyaging. London: Jonathan Cape. ISBN 1-84413-314-1.

Richmond, Marsha (January 2007). “Darwin Online: Darwin’s Study of the Cirripedia”. Darwin Online.

Desmond, Adrian; Moore, James (1991), Darwin, London: Michael Joseph, Penguin Group, ISBN 0-7181-3430-3

 

Tagged with: , , , , , , ,
Posted in Museum

Leave a Reply

Your email address will not be published. Required fields are marked *

*