求教难句：og 37

原句 In considering possible explanations for this finding, the researchers dismissed demographic bias because older individuals were not overrepresented in the fossil samples。
偶对上文红色部分的理解是：在化石样品中，年老的个体并没有超出正常的比例。即这部分年老的个体不具有单独的代表性。
但是，在og中的解释：because older individuals were not disproportionately represented among the fossils. The implication of this conclusion is that older individuals might be expected to have a higher rate of tooth breakage.
这样一来，og的解释理解是年老的个体有个性，即有代表性。与偶的双重否定表肯定的理解相反？尽管这题做对了，但是仍想好好理解此句，请nn赐教，深谢。