[单项选择]

Natural Selection

First coined by Darwin, the term natural selection refers to the process at the core of evolutionary theory. Simply put, Darwin believed that every living organism had to struggle to survive and reproduce. By random chance, some individuals in a species would have characteristics that made them better adapted to this struggle than their contemporaries. Such individuals would be more likely to reproduce and pass their characteristics on to their offspring. Over many generations, a series of small differences in characteristics would accumulate, until eventually the creatures that were produced would be so different from their original ancestors that they would constitute a new species. ■

• (A) Although Darwin did not know how variations between individual members of the same species were able to arise in the first place or how such traits could then be passed on from species to species, we now know that this process
  A. ■(Ａ)
  B. ■(Ｂ)
  C. ■(Ｃ)
  D. ■(Ｄ)
  

[单项选择]
First coined by Darwin, the term natural selection refers to the process at the core of evolutionary theory. Simply put, Darwin believed that every living organism had to struggle to survive and reproduce. By random chance, some individuals in a species would have characteristics that made them better adapted to this struggle than their contemporaries. Such individuals would be more likely to reproduce and pass their characteristics on to their offspring. Over many generations, a series of small differences in characteristics would accumulate, until eventually the creatures that were produced would be so different from their original ancestors that they would constitute a new species. ■

• (A) Although Darwin did not know how variations between individual members of the same species were able to arise in the first place or how such traits could then be passed on from species to species, we now know that this process
  A. characteristics.
  B. individuals.
  C. species.
  D. contemporaries.
  

[填空题]Natural selection acts in the form of variation with a species.

[单项选择]Natural selection is defined as the process ______ the course of evolution by preserving those traits best adapted for an organism’s survival.
A. to which directs B. of which directs it
C. directs it D. that directs

[填空题]{{B}}Darwin and His Theory{{/B}} Darwin was born in 1809 as the son of a physician. He earlier planned to become a{{U}} (1) {{/U}}in the Church of England. Later he accepted an invitation to serve as an unpaid naturalist on the H. M.S. Beagle, and joined in the{{U}} (2) {{/U}}scientific expedition to the Pacific coast of South America in 1831. The book On the Origin of Species was published in 1859 and aroused a storm of{{U}} (3) {{/U}}He continued to write and publish his works on biology throughout his life. He died on 1882 and lies buried in Westminster Abbey. Darwin’s general theory presumes the development of life from non-life and stresses a purely naturalistic "descent with{{U}} (4) {{/U}}", the result of which is an entirely different organism. What Darwin brought to the old philosophy of evolution is a new mechanism called "natural selection". It acts to preserve and{{U}} (5) {{/U}}minor advantageous genetic mutations. It is the preservation of a{{U}} (6