How does independent assortment create more than eight million possible chromosome combinations in human gametes?

In humans, the diploid number of chromosomes is 46, which organize into 23 homologous pairs during meiosis. Each pair consists of one chromosome of maternal origin and one of paternal origin.

The law of independent assortment dictates that the maternal and paternal members of these different chromosome pairs are distributed into gametes independently of one another. Because each of the 23 pairs can orient in two different ways during the first meiotic division, the number of possible chromosomal combinations in the resulting haploid sex cells is calculated as $2^{23}$. This mathematical result equals 8,388,608 unique combinations of grandmaternal and grandpaternal chromosomes.1

It is important to note that this figure is an underestimate of actual genetic diversity. The process of crossing over allows homologous chromosomes to exchange segments, creating new combinations of genes within individual chromosomes beyond the variation provided by independent assortment alone.1