Is exclusion from jury service of a "substantial and identifiable class" class of citizens sufficient to cause an adverse effect on the integrity of the jury?

"'. . . "[T]he exclusion from jury service of a substantial and identifiable class of citizens has a potential impact that is too subtle and too pervasive to admit of confinement to particular issues or particular cases . . . when any large and identifiable segment of the community is excluded from jury service, the effect is to remove from the jury room qualities of human nature and varieties of human experience, the range of which is unknown and perhaps unknowable. . . ." . . . ". . . We are simply not in a position to make fine judgments as to the fungibility of identifiable segments of the community.'"" (People v. Motton, supra, 39 Cal.3d at p. 606, fn. omitted, italics in original.)