Here's why:
* Crossing over: During meiosis (the process of cell division that creates gametes, like sperm and egg cells), homologous chromosomes (one from each parent) exchange genetic material. This exchange, known as crossing over, shuffles alleles (versions of genes) between chromosomes.
* Independent assortment: Chromosomes line up randomly during meiosis, meaning that the combination of chromosomes (and thus, the genes they carry) that end up in a gamete is also random.
Together, crossing over and independent assortment create a huge number of possible gene combinations in offspring, leading to genetic diversity within a species.
