I know, I know, what the hell is a fourth cousin?

我知道我知道， 四表哥是什么鬼？

So, you can have first cousins, second cousins, third cousins, fourth cousins, and so forth.

所以，你可以有第一代堂兄弟、第二代堂兄弟、第三代堂兄弟、第四代堂兄弟等等。

Large family trees give us the opportunity to analyze both close relatives, such as twins, all the way to distant relatives, even fourth cousins.

庞大的家谱树给了我们分析这些近亲，比如双胞胎，到远房亲戚，甚至四代表亲这样的机会。

However, once we start talking about second, third, and fourth cousins, then we're talking about great-grandparents and great-great-grandparents, the parents of my grandparents and their parents and so forth.

然而，一旦我们开始谈论第二、第三和第四堂兄弟姐妹，那么我们就会谈论曾祖父母和曾曾祖父母、我祖父母的父母和他们的父母等等。

As James Fowler, professor of medical genetics at UC San Diego says, " Most people do not even know their fourth cousins but somehow manage to select as friends the people who resemble our kin."

正如加州大学圣地亚哥分校医学遗传学教授詹姆斯·福勒所说：“大多数人甚至并不认识他们的第四代堂兄弟姐妹，但是某种程度上，却成功地选择了那些像我们亲戚的人们作为朋友。”