Which of the following is the best example of natural selection? A)A population of a rabbits decreases in number as some move to another area.
B)The shell of a crab becomes harder over time as a result of being hunted by a predator.
C)A person's muscles become firmer from riding a bike for exercise.
D)A cheetah living in a zoo lives 10 years longer than average.

What are chlorofluorocarbons made of

1. variations in a population of moths allow for some of its members to be able to adapt to environmental changes. the better adapted of the moths will be able to survive the change and thus prevail as the “fittest” of the species. (a) describe three mechanisms in which variation can occur within a species population. (b) explain which mechanism or mechanisms would be responsible for the survival of a population of peppered moths better than white moths in an environment affected by industrial soot. justify your answer.

Ascientific idea becomes valid when it is what?