New genetic traits upon which natural selection can act usually arise from __________.
A)increases in cell size and shape
B)mutations
C)the demands of the environment
D)the need to become adapted to a new environment

Question

Quizplus · Accepted Answer

New genetic traits usually arise from mutations, which are random changes in the DNA sequence of an organism. These mutations can occur spontaneously or as a result of exposure to mutagens such as radiation or certain chemicals. Natural selection acts upon these new traits by favoring those that increase an organism's fitness in its environment.

New Genetic Traits Upon Which Natural Selection Can Act Usually