There’s a pre­scrip­tion for giv­ing a good lec­ture: ​“First you tell ​‘em what you’re going to tell ​‘em, then you tell ​‘em, then you tell ​‘em what you told ​‘em.” Rab­bi Kleiman fol­lows this pre­scrip­tion very well in his inter­est­ing book, clear­ly out­lin­ing the sci­en­tif­ic basis involved in trac­ing gene groups in both the male and female lines. I am par­tic­u­lar­ly impressed by his care in spelling out what these genet­ic analy­ses do not establish. 

Chap­ters dis­cussing the his­tor­i­cal paths of var­i­ous Jew­ish com­mu­ni­ties, ​“lost” tribes (both ancient and mod­ern), and the halachic impli­ca­tions of Kohan­ic and Levitic descent pro­vide inter­est­ing sup­ple­ments to the genet­ic analy­sis por­tions of the book. Reprints of arti­cles from tech­ni­cal jour­nals and exten­sive notes per­mit inter­est­ed read­ers to do fur­ther inves­ti­ga­tion into the sci­en­tif­ic details.