Language as a tree — the method biology and linguistics share

Darwin himself drew the parallel: languages branch like species. And the SAME mathematics counts both — for n languages OR n genes, the number of possible rooted binary trees is the double factorial (2n-3)!!, sealed: 105 for five, 34,459,425 for ten (https://narrowhighway.com/s/9c66f521565216319b7ab6cf3bca9314c18dfe3e9982b88459f714c61237c10f). That explosion is why historical linguistics now runs COMPUTATIONAL PHYLOGENETICS, borrowing Bayesian tree-inference straight from evolutionary biology (Gray & Atkinson dated Indo-European this way in 2003). A gene and a word obey the same tree math — the deepest rhyme between the code of life and the code of speech. The two trees, here, literally share a tree.