Robert Edmond Grant was an Edinburgh-trained physician, who gave up the medical profession to study invertebrates. He was an early advocate of evolutionary thought (a strong supporter of Geoffroy and Lamarck and their views), and cited Erasmus Darwin’s Zoonomia in his medical dissertation. It is worth noting that Grant was mentored by the geologist Robert Jameson, now established as the author of an anonymously authored distinctly transmutationist 1826 paper “Observations on the Nature and Importance of Geology.” Early in his career, Grant traveled to Paris (multiple times between 1815 and 1820), and was acquainted with both Cuvier and Geoffroy.

Grant is often memorialized as Charles Darwin’s instructor in invertebrate zoology, while Darwin was a medical student at the University of Edinburgh between 1825 and 1827. From their joint collecting trips to the shore, Grant introduced Darwin to the world of research and microscopic dissection – and this led to the Darwin’s first scientific paper, delivered at the Plinian Society in 1827. As Darwin later wrote in his autobiography, “He [Grant] one day, when we were walking together, burst forth in high admiration of Lamarck and his views on evolution. I listened in quiet astonishment, and as far as I can judge, without any effect on my mind.” Darwin’s introspection aside, Grant surely played a critical role in fostering Darwin’s love of natural history, taste for research, and willingness to think openly about transmutation.

Grant’s first published hints of his evolutionist views appeared in a paper on the freshwater sponge, Spongilla friabilis (1826).  Here, he made a seemingly evolutionary argument about the descent of marine sponges from their freshwater ancestors:

“From this greater simplicity of structure, we are forced to consider it as more ancient than the marine sponges, and most probably their original parent; and, as its descendants have greatly improved their organization, during the many changes that have taken place in the composition of the ocean, while the spongilla, living constantly in the same unaltered medium, has retained its primitive simplicity.”(283)

In 1827, Grant became a professor at the newly founded University College of London, where his lectures on comparative anatomy endorsed Geoffroy’s “unity of plan” concept. It is clear that this idea of homology, and gradated anatomical transitions between different groups (living and fossil) in the animal kingdom greatly influenced Grant’s transformism.  In his inaugural address and lecture in 1828 Grant argued that the science of zoology “enquires into the origin and duration of entire species, and the causes which operate towards their increase or their gradual extinction; the laws which regulate their distribution, and the changes they undergo by the influence of climate, domestication, and other external circumstances.”

In 1833, again in his introductory address at the opening of the Medical School of the University of London, Grant wrote: “Extending his view to the remnants of organic beings embalmed in the earth, he [the comparative anatomist] finds that this kingdom has itself been gradually developed from simple to compound, that its roots are lost in the depths of the earth, and its extreme branches only are visible on the surface.”

Later in life, Darwin would distance himself from Grant, likely because of Grant’s radical materialism, politically reformist views, and general descent in reputation among natural historians. After the publication of On the Origin of Species, Grant made sure to link his name to that of Charles Darwin, particularly through the publication of an 1861 book on the animal kingdom – Tabular View of the Primary Divisions of the Animal Kingdom intended to serve as an outline for an elementary course of Recent Zoology – that he dedicated to Darwin. In addition to highlighting an excerpt of an evolutionary profession made in his 1834 Lectures, Grant made sure to remind the world of their close connection in Edinburgh, where “nearly forty [years] have already rapidly fled away since you and I were busied in exploring microscopically the delicate structures and the living phenomena of the lowest organisms abounding in the rich fauna of the Firth of Forth.”