2025/06/11 by Fischer, Mareike, Kelk, Steven, Alferez, Sofia Vazquez
#Combinatorics (math.CO) #FOS: Biological sciences #FOS: Mathematics #Populations and Evolution (q-bio.PE)
paper · doi:10.48550/arxiv.2506.09888
In this article we prove that the distance dMP(T1,T2) = k between two unrooted binary phylogenetic trees T1, T2 on the same set of taxa can be defined by a character that is convex on one of T1, T2 and which has at most 2k states. This significantly improves upon the previous bound of 7k-5 states. We also show that for every k ≥ 1 there exist two trees T1, T2 with dMP(T1,T2) = k such that at least k+1 states are necessary in any character that achieves this distance and which is convex on one of T1, T2. We augment these lower and upper bounds with an empirical analysis which shows that in practice significantly fewer than k+1 states are usually required.