Over the years, biologists have suggested two main pathways by which sexual selection natural selection for characters that confer success in competition for a mate as distinguished from competition with other species; also: the choice of a mate based on a preference for certain characteristics may have shaped the evolution of male birdsong. In the first place, male competition and intrasexual selection produce relatively short, simple songs used mainly in territorial behavior. In the second place, female choice and intersexual selection produce longer, more complicated songs used mainly in mate attraction; like such visual ornamentation as the peacock’s tail, elaborate vocal characteristics increase the male’s chances of being chosen as a mate, and he thus enjoys more reproductive success than his less ostentatious rivals. The two pathways are not mutually exclusive, and we can expect to find examples that reflect their interaction. Teasing for microscopic examinatio
A. showing that intrasexual selection has a greater effect on birdsong than does intersexual selection
B. contrasting the role of song complexity in several species of birds
C. describing research confirming the suspected relationship between intersexual selection and the complexity of birdsong
D. demonstrating the superiority of laboratory work over field studies in evolutionary biology
Traditionally, universities have carried out two main activities: research and teaching. Many experts would argue that these activities play a critical role in serving the community. The fundamental question, however, is: how does the community want or need to be served
In recent years universities have been coming under increasing pressure from both the government and the public to ensure that they do not remain "ivory towers" (象牙塔) of study separated from the realities of everyday life. University teachers have been encouraged, and in some cases constrained (强逼), to provide more courses which produce graduates with the technical skills required for the commercially useful purpose. If Aristotle wanted to work in university in the UK today, he would have a good chance of teaching computer science but would not be so readily employable as a philosopher.
A postindustrial society requires large numbers of computer programmers, engineers, managers and techni
A. the society needs both technical skills and arts
B. art is useful only when it is made into a money earner
C. universities should not provide literature or art courses
D. the promotion of economic growth is the only goal of today’s society
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