Great Migration: Life for Migrants in the City. By the end of 1919, some 1 million blacks had left the South, usually traveling by train, boat or bus; a smaller number had automobiles or even horse-drawn carts.
Genetic variation is increased by meiosis During fertilisation, 1 gamete from each parent combines to form a zygote. Because of recombination and independent assortment in meiosis, each gamete contains a different set of DNA.
Natural selection, crossing over, and independent assortment are methods of genetic recombination. Added 156 days ago|5/15/2015 2:21:24 PM. This answer has been confirmed as correct, not copied, and helpful.