1. But so far the only evidence for a genetic component has been through statistics, the relationship being inferred mathematically from comparisons of twins and other such studies of close relatives.
    但迄今为止，遗传基因所占比重的仅有的证据只是一些统计数据，即，从对双胞胎的比较，以及对其他血缘接近者的研究中得出的数学统计关系。

2. And because such all-round ability is less common, this would be the reason for there being fewer mathematically talented girls.
    又因为这样全面的能力并不常见，这就解释了为何有数学天赋的女孩较为少见。