According to Darwin's model of evolution, variation among individuals in a population is crucial for evolution to occur. The best statement that describes the source of this variation among members of a species is:
1. Variation among individuals may arise as a result of mutations in the genetic code.
Mutations are changes in the DNA sequence that can create new genetic variations within a population. These mutations can be caused by various factors such as errors during DNA replication, exposure to mutagens like radiation or chemicals, or even through genetic recombination during sexual reproduction. When mutations occur, they introduce new genetic diversity into a population, leading to variations among individuals. This variation provides the raw material upon which natural selection can act, allowing for the adaptation and evolution of species over time.
While factors like geography, climate, access to resources, and gene expression can influence variations among individuals to some extent, mutations in the genetic code are the primary source of new genetic variations that drive evolutionary changes in populations.
