2022年考博英语阅读篇章材料(27)

　　新东方在线考博频道给大家整理的相关内容，希望能够对大家的考博考试备考有所帮助，更多有关考博的备考内容，欢迎随时关注新东方在线考博频道。

　　(27)

　　Off with their heads

　　The kings and queens of England may have murdered their closest kin to

　　secure the throne, but they still stayed true to a basic rule of evolutionary

　　biology.

　　The history of Britain between the 14th and 16th centuries is full of epic

　　tales of jealousy, intrigue and murder. To ensure their right to the throne

　　remained unchallenged, members of the royal family frequently murdered their

　　closest relatives. Both Henry IV and Henry VIII killed five cousins each.

　　John McCullough, an evolutionary biologist at Cambridge University, and his

　　colleagues at Indiana State University felt sure the lure of the ultimate prize

　　would force British monarchs to break free from the shackles of their own

　　selfish genes. "It was kill or be killed," he says.

　　But to their surprise, the researchers found that despite the high death

　　toll, the kings and queens of England all obeyed a golden theory of biology

　　known as Hamilton's rule.

　　Helping hand

　　According to the theory, people or animals can pass on their genes by

　　helping their relatives. That means they should be more willing to help brothers

　　or sisters, who share half their genes on average, than more distant relatives

　　who share less.

　　But relatives also have a nasty habit of competing with you for resources,

　　be they chicks squabbling over food, or heirs fighting for the throne. And this

　　is where the flip side of Hamilton's rule comes in.

　　If you kill two brothers, say, you've essentially wiped out your genetic

　　identity rather than preserving it for future generations, says McCullough.

　　"Then you have really damaged yourself in an evolutionary sense. So you can

　　eliminate relatives but only up to a certain level."

　　But it turns out no king or queen, from Edward III who succeeded to the

　　throne in 1327 to Elizabeth I who died in 1603, killed enough relatives to wipe

　　out the equivalent of their own genetic inheritance (see graphic).

　　Edward IV, who reigned in the late 15th century, was the worst offender,

　　executing his brother, George, Duke of Clarence, and five cousins, including

　　Henry VI and Edward, Prince of Wales. Yet even Edward IV's victims shared only

　　two-thirds of his genes in total.

　　"I was astounded. We thought that at least two or three would violate

　　[Hamilton's rule] because some very close relatives were killed," says

　　McCullough. "They had no theory of genetics at the time so they were simply

　　operating under their own set of rules," he says. "As it turns out, it is in

　　accord with scientific expectations."

　　以上就是新东方在线考博频道给大家整理的相关内容，希望对大家有所帮助，更多备考内容，欢迎随时关注新东方在线考博频道。

2022考博精选好考，点击图片查看详情！