Martial Arts and Convergent Evolution

One of the myths one encounters in debates on martial arts is that of the "single origin." This is the false idea that there must have been one "original art," and that others are derivatives. Some say Chinese kung fu is the mother of all arts, and that the Shaolin Temple is its birthplace. Others say the semi-mythical Bodhidharma is the origin, as he supposedly taught the Shaolin monks how to fight. Still others claim that Egypt is the origin, because of the wrestling art in the tomb of Baqet III, more popularly known as part of the Beni Hasan tombs in Egypt dating to the 21st century BCE.

It's a myth. Plenty of people like Iain Abernethy and friends have explained why there is no single origin. While it's true that some arts did indeed draw upon techniques from prior arts, it does not mean there is some sort of chain or tree that links all arts and techniques to a common ancestor.

Recognizing that the single origin is a myth, how should we think about the process that causes seemingly unrelated arts and techniques to appear or function like each other?

Today I encountered a term on Reddit that was new to me: "convergent evolution." A search for martial arts contexts yielded blog posts on that very phenomenon from 2015, 2014, 2013, and 2010. The first real exposition of the concept with respect to martial arts, however, appears to be this 2009 post about Colonel Rex Applegate. I found a couple uses of the term in forums from 2006 and 2004, but they were only mentions and not expositions. 

So who invented the term convergent evolution? Wikipedia has plenty to say about the theory, but nothing about the origin. The earliest article I found on Google Scholar dates from 1921 and is titled "The Study of Human Implements as an Aid to the Appreciation of Principles of Evolution and Classification," by E. J. Salisbury in The New Phytologist, Vol. 20, No. 4 (Nov. 2, 1921), pp. 179-184. It's online and free, and is the source for the image at the top of the post. 

Going forward I intend to use the term convergent evolution to describe the tendency for arts to independently arrive at the same techniques, without the need for there to be a single common origin.