21.   The legend of Plumed Serpent began several thousand years before the birth of Christ and evolved through time as different cultures adopted the myth to meet their needs.

22.   The next generations of the family position themselves impatiently as the system evolves through internal power wranglings.

23.   These include antibiotic-resistant bacteria believed to have evolved through the nearly universal practice of giving food animals low doses of antibiotics to enhance their growth.

24.   This is a sign that the chromosomal pairs evolved through asexual reproduction over a long time.

25.   This is the way the series has evolved through the season.

26.   Though Abraham may be at the root of these three religions, each faith evolved through time and tradition.

27.   To say that the planting evolved through trial and error is a calm understatement of what ensued.

28.   Universities exist, in part, to prove that culture evolves through sympathetic accretion, not destruction of the past.

29.   You have to treat it as something that continuously evolves through improvisation.

30.   Annan said Thursday that U.S. thinking about the force had evolved through talks with Mandela, the Organization of African Unity and the United Nations.