Struthers' ligament

The ligament is not always present, and there is some debate as to its prevalence. Struthers originally estimated that it was present in 1% of humans. ==Historical significance==

The structure was originally depicted by Tiedemann, and later by Knox in the early 19th century, but John Struthers was the first to draw attention to this structure in 1848 as a "peculiar process" that bore curious resemblance to anatomy that he had seen in cats. This observation was one of many that Struthers made in subsequent investigations of vestigial and rudimentary structures, and in sharing these observations with his contemporary, Charles Darwin, provided significant evidence for the theories of evolution. Charles Darwin took the ligament to mean that humans and other mammals had a common ancestor, and used Struthers' work as evidence in Chapter 1 of his Descent of Man (1871). Struthers went on to create a museum of Comparative Anatomy filled with zoological specimens to illustrate Darwin's theory of common descent. ==References==