Evolution of non-biological systems
Evolution depends on mutations happening in DNA sequences, which are then propagated as cells divide. As evolutionary biologists, we have a wide range of computer programs that can use DNA sequence data from different organisms to infer their evolutionary history – phylogenetic analysis. However, many other things in the world follow a pattern of copying with the incorporation of changes. One example of these is old written texts. As scribes copied manuscripts, in the days before printing, they made mistakes and those mistakes were propagated when the manuscripts were copied again. This process is very similar to the accumulation of mutations in DNA sequences.
We showed that it is possible to apply phylogenetic tree-building programs, designed for use with sequence data, to the written texts in manuscripts. In essence, each word becomes a character (like a nucleotide) and the texts can be fed into phylogenetic programs.
Figure: Phylogenetic analysis of Chaucer’s Canterbury Tales. The figure shows a phylogenetic analysis using the program SplitsTree of the Prologue to the Wife of Bath’s Tale. The coloured groups had been identified previously by classical scholarship. The figure shows how well the phylogenetic analysis agrees with the conclusions of classical scholarship, but phylogenetics provides conclusions in a fraction of the time. Figure modified from Barbrook et al. (1998) Nature doi.org/10.1038/29667.
We have coined the term ‘phylomemetics’ for this kind of analysis, based on Richard Dawkins’ concept of a meme, analysed by phylogenetic methods. We have a wide range of collaborations applying phylogenetic analysis to sets of texts, most recently including music manuscripts. Phylomemetics provides textual scholars with a means of rapid analysis as an additional tool for them to use.
More information:
“A phylogenetic analysis of two preludes from J.S. Bach’s Well-tempered Clavier Book II.” Windram HF, Charlston T, Tomita Y, Howe CJ. (2022) Early Music 2022:caac027 https://doi.org/10.1093/em/caac027
“Phylomemetics - evolutionary analysis beyond the gene” Howe CJ, Windram HF. (2011) PLoS Biology 9 e1001069. https://doi.org/10.1371/journal.pbio.1001069