In one, they sequence the DNA of particular genes in many individuals with or without some determined health condition and look for differences between the two groups. This genetic approach measures effects that have accumulated over hundreds to thousands of generations, and the message is clear: humans have evolved in these respects fairly recently, some in one direction, some in another, depending on their environment and other conditions encountered.
科学家们运用两种方法进行研究：一是提取出具有特定健康问题的人的特定基因DNA序列，将其与其他人群进行对比并找出两者的差异之处。这种基因方法可以测量出那些经过数百甚至数千代人积累下来的进化效果，而且结果很明确：人类是在一个相对较短的时期内对这些特性进行进化的，有些人向这个方向进化，而另一些人则选择了不同的路径，这取决于他们的生存环境以及其他特殊情况。