he park is inhabited, and many villages, some of whom the ancestors are dating back to the Angkor period are scattered throughout the park
公园里有人居住，公园里散布着很多村庄，其中一些村庄的祖先可以追溯到吴哥窟时期
请问，whom是连接代词，其先行词是什么？为何the ancestors are dating back to the Angkor period这句话要用目前进行时？还有，两个逗号的不太了解。
我看这个句子有错误。
