The evolution of languages closely resembles the evolution of haploid
organisms. This similarity has been recently exploited \cite{GA,GJ} to
construct language trees. The key point is the definition of a distance among
all pairs of languages which is the analogous of a genetic distance. Many
methods have been proposed to define these distances, one of this, used by
glottochronology, compute distance from the percentage of shared ``cognates''.
Cognates are words inferred to have a common historical origin, and subjective
judgment plays a relevant role in the identification process. Here we push
closer the analogy with evolutionary biology and we introduce a genetic
distance among language pairs by considering a renormalized Levenshtein
distance among words with same meaning and averaging on all the words contained
in a Swadesh list \cite{Sw}. The subjectivity of process is consistently
reduced and the reproducibility is highly facilitated. We test our method
against the Indo-European group considering fifty different languages and the
two hundred words of the Swadesh list for any of them. We find out a tree which
closely resembles the one published in \cite{GA} with some significant
differences.

通过比较词汇的遗传距离，在 Swadesh 列表中对同义词进行归一化的 Levenshtein 距离计算，提出了一种降低个人判断主观性的语言之间遗传距离计算方法，并利用该方法构建了一种印欧语系的语言树。