The exchange of genetic material between non-sister chromatids that may result in new gene combinations on the chromosomes is called the random assortment. It involves formation of random combinations of chromosomes in meiosis and of genes on different pairs of homologous chromosomes by the passage according to the laws of probability of one of each diploid pair of homologous chromosomes into each gamete independently to each other pair.
They concluded that horses evolved with the emergence of grasslands and an increase of predators. The digits of their early Eocene ancestor evolved into hooves.
