1.   Competition and struggle exist, as parts of the mechanism by which organic life evolves to new and superior forms.

2.   As life evolved, animals needed a more complex brain for finding food and sex, and so developed a central nervous system.

3.   Before I knew it, my once-simple life had evolved into a Cathy cartoon.

4.   Besides answering questions about how life could have evolved elsewhere in space, the research might shed light on evolution on Earth.

5.   All of these can yield information about how life evolved and about the past environments.

6.   But political life evolved to the point where Clinton could risk being artfully confessional about his sex life, after first establishing that it would become an issue.

7.   Despite the fact that there may be more planets capable of harboring life, some scientists doubt that intelligent life has ever evolved.

8.   Even if life did evolve on Mars, some researchers think our prospects of finding actual fossils are slim.

9.   Far from the battlefields of public policy, biologists said they saw in the contours of the gene map revelations about how life evolved.

10.   Going from a typical suburban mother and professional to a national AIDS activist, she has seen her life evolve immensely.