Section A Directions:In this section, there
is a short passage with 5 questions or incomplete statements.Read the
passage carefully. Then answer the questions or complete the statements in the
fewest possible words. Please write your answers on Answer Sheet
2.
Are you a social butterfly, or do you prefer being at the edge of a group
of friends Either way, your genes and evolution may play a major role, US
researchers reported on Monday. While it may come as no
surprise that genes may help explain why some people have many friends and
others have few, the researchers said, their findings go just a little farther
than that. "Some of the things we find are frankly
bizarre," said Nicholas Christakis of Harvard University in Massachusetts, who
helped conduct the study. "We find that how
interconnected your friends are depends on your genes. Some people have four
friends who know each other and some people have four friends who don’t know
each other. Whether Dick and Harry know each other depends on Tom’s genes,"
Christakis said in a telephone interview. Christakis and
colleague James Fowler of the University of California San Diego are best known
for their studies that show obesity, smoking and happiness spread in networks.
For this study, they and Christopher Dawes of UCSD used
national data that compared more than 1,000 identical and fraternal twins.
Because twins share an environment, these studies are good for showing the
impact that genes have on various things, because identical twins share all
their genes while fraternal twins share just half.
"We found there appears to be a genetic tendency to introduce your
friends to each other," Christakis Said. There could be
good, evolutionary reasons for this. People in the middle of a social network
could be privy to useful gossip, such as the location of food or good investment
choices. But they would also be at risk of catching
germs from all sides-in which ease the advantage would lie in more cautious
social behavior, they wrote in the proceedings of the National Academy of
Sciences. "It may be that natural selection is acting on
not just things like whether or not we can resist the common cold, but also who
it is that we are going to come into contact with," Fowler said in a statement.
Which word(s) in the passage can best replace the phrase "natural selection"