Among 2392 marriages in one recent year, 19 couples had surnames identical to those of one or more other couples. Repetitions of pairs of names were significantly more frequent (x2(1) = 4.19) than expected at random. A modified formulation of the frequency of repetitions (RP2) was more informative about population structure than was marital isonymy, of which there were two instances. A tendency to a continuing small but significant reduction in genetic variability therefore can be inferred.
Lasker, G W.; Mascie-Taylor, C G.N; and Coleman, D A.
"Repeating Pairs of Surnames in Marriages in Reading (England) and Their Significance for Population Structure,"
3, Article 10.
Available at: https://digitalcommons.wayne.edu/humbiol/vol58/iss3/10