Languages disfavor word forms containing sequences of similar or identical
consonants, due to the biomechanical and cognitive difficulties posed by
patterns of this sort. However, the specific evolutionary processes responsible
for this phenomenon are not fully understood. Words containing sequences of
identical consonants may be more likely to arise than those without; processes
of word form mutation may be more likely to remove than create sequences of
identical consonants in word forms; finally, words containing identical
consonants may die out more frequently than those without. Phylogenetic
analyses of the evolution of homologous word forms indicate that words with
identical consonants arise less frequently than those without, and processes
which mutate word forms are more likely to remove sequences of identical
consonants than introduce them. However, words with identical consonants do not
die out more frequently than those without. Further analyses reveal that forms
with identical consonants are replaced in basic meaning functions more
frequently than words without. Taken together, results suggest that the under
representation of sequences of identical consonants is overwhelmingly a
byproduct of constraints on word form coinage, though processes related to word
usage also serve to ensure that such patterns are infrequent in more salient
vocabulary items. These findings clarify previously unknown aspects of
processes of lexical evolution and competition that take place during language
change, optimizing communicative systems.

语言的演化过程中，相同辅音的连续出现并不常见，这主要是由于生物力学和认知上的困难。较容易出现相同辅音的词可能比其他词更常见，而词形变异过程往往倾向于去除相同辅音的连续出现。然而，带有相同辅音的词并不比其他词更容易消失，而是更常被取代。这些发现有助于我们更好地了解词汇演化和语言变化过程中的竞争规律。