SignBase

From time to time I ponder about the invention and variety of alphabets – alphabets which have been around since perhaps 5,000BP. See for example, reference 1. Other people have clearly been pondering about what came before alphabets, with reference 2 being one result.

It seems that people have been carving symbols into ivory, bone, stone and other materials for a very long time, and this paper documents collecting data about those symbols from something more than 500 small objects, mostly from Europe, dating from around 45,000BP to 30,000BP, and feeding that data into a database called SignBase.  Mobile objects to cognoscenti.

From these 500 artefacts the authors have extracted around 30 symbols, mostly geometric, not to say abstract, but at least 2 being more figurative. Illustrated above. With one weakness being that their frequency distribution is very skewed, with notches, straight lines and crosses accounting for a large proportion of the total and with nearly half the symbols showing up less than 5 times. 

Nevertheless, it will be interesting to see how this database grows and whether anyone succeeds in attaching any meaning or significance to these symbols. Will the notched artefacts mostly turn out to have been scoring sticks for successful hunters?

A few technical points.

Objects are coded with a binary vector indicating presence or absence of each symbol and some effort was put into testing the reliability of such coding. Is there reasonable agreement about whether this or that symbol is present on this or that bit of ivory? The distance between objects is measured by the Jaccard index, a simple function on a pair of such vectors – a distance which is zero a lot of the time given the skew noted above – so we don’t have a proper metric space. A tree can then be obtained using the simple UPGMA algorithm, although the authors are sensibly agnostic about whether such a tree is of much help here.

Reference 1: https://psmv4.blogspot.com/2020/10/more-armenia.html. 

Reference 2: SignBase, a collection of geometric signs on mobile objects in the Paleolithic - Ewa Dutkiewicz, Gabriele Russo, Saetbyul Lee & Christian Bentz – 2020. Brought to me by the 907'th number of the EAORC bulletin.

Reference 3: https://en.wikipedia.org/wiki/Jaccard_index.

Reference 4: https://en.wikipedia.org/wiki/UPGMA. 

Reference 5: ‘circular cladograms’ a search key for Google for those who like circular presentation of their trees, as at references 6 and 7 below.

Reference 6:  https://psmv3.blogspot.com/2016/02/a-story-about-tree.html. 

Reference 7: http://psmv3.blogspot.co.uk/2016/02/tree-of-life.html.