A major advancement in lexicostatistics and glottochronolgy occurred in 1952 with Morris Swadesh, with his eponymous Swadesh list of 215 basic words that he believed would be common to every language, originally this was purely based on his own opinion, however later revisions would comprise of 3 main types of words: Basic nouns (including familial terms, objects found in nature and anatomical parts), basic verbs (including basic actions and reactions) and pronouns (you, I, they, etc.) Swadesh chose these words on the basis that these non-cultural words would be resistant linguistic errors that imply false parsimony (such as word borrowing and analogy), and also believed that these words would evolve at the same rate regardless of language or population. Over time Swadesh narrowed down the list to just 100 words, 

Genetic linguistic research methods

Bayesian Phylogenetics

Modern day linguistical phylogenetic methods are usually based on Bayesian Markov Chain Monte Carlo (MCMC) methods, in essence a mathematical model that can extrapolate
To explain it we will start with Bayes' theorem
\(\left(P\left(H\ \right|\ E\ \right)=\frac{\left(P\left(E\ \right|\ H\right)\ \cdot\ P\left(H\right)}{P\left(E\right)}\)

Bayesian phylogenetics & polynesian migration

Current theories of Polynesian people's origin fall into two main camps: Express Train theory and the Entangled Bank theory \cite{Kayser_2000}. The more popular theory, Express Train, first put forward by Jared Diamond \cite{Diamond1988}posits that Polynesian migration originated in Taiwan and started relatively recently 3000-1000BCE, and migrating via the Philippines and New Guinea and reaching Melanesia by roughly 1400BCE and reaching Samoa by 900BCE. Entangled Bank theory however puts forward that there was no single 'express train' to Polynesia, it emphasises smaller migration as well as the long cultural and genetic interactions between the Polynesians, Melanesians and East Asians. Newer theories such as Kayser et al.'s Slow Boat theory attempts to marry these two ideas, while supporting a Tawainese origin and rapid migration to Melanesia, then suggests that upon reaching Melanesia migration slowed, and there was a long delay (leading to cultural and genetic admixture) before migration to Polynesia. 
Contemporary linguists have attempted to solve these competing theories using Bayesian inference, an important paper being Language Phylogenies Reveal Expansion Pulses and Pauses in Pacific Settlement , which focuses on how (timewise) the migration took place, both this and Language trees support the express-train sequence of Austronesian expansion.

Criticism of bayesian phylogenetics

\cite{churchill1912} \cite{Walker_2010} \cite{Diamond_2003}\cite{Greenhill_2010}\cite{churchill1911}\cite{Gray_2009}\cite{2013}\cite{Gray_2000}

Conclusion