Question

1. in paragraph 15, you learned that genetic variation contributes to evolution by natural selection. what causes a variation?

evolution by natural selection 263

Explanation:

Genetic variation is caused by several factors. Mutation, which is a change in DNA sequence, introduces new alleles. Genetic recombination during meiosis (crossing - over and independent assortment) shuffles existing alleles. Also, gene flow, the transfer of genes between populations, can bring in new genetic material and cause variation.

Answer:

Genetic variation is caused by mutation (changes in DNA), genetic recombination (crossing - over and independent assortment in meiosis), and gene flow (transfer of genes between populations).