In recent centuries humans have, to a greater extent than ever before in our history, moved great distances and mated with individuals who were born in different places. If this patrem continues in the future, which of the following is the most likely evolutionary consequence?

a. Allele frequencies will become more similar across populations, adaptation to local conditions will be reduced
b. Mechanisms of evolution besides migration will cease to occur for any human population
c. The overall rate of evolution will slow down to the point of being unobservable
d. The effects of genetic drift will increase, so global allele frequencies will begin to change very drastically

A

Explanation:

Before humans could travel the way they do now, population was adapted to local conditions. Therefore gene frequencies were also greatly different between these populations due to these local adaptations.  However, increased ease of travel has caused increased gene flow between human populations. This means alleles are being increasingly distributed in population across the planet making the population more or less homogenous. Diversity between population therefore decreases and a decrease in diversity causes a reduced ability for adaptation towards local climatic changes.  

answer: land bridge theory. land bridge theory held that shifting portions of dry land explained the finding of identical species on different continents. plate tectonic theory eventually eliminated the land bridge theory.

hi~~

i would say that hybridization occurs frequently in nature, because there are many types of hybrids that have occurred naturally, such as the mule (male donkey + female horse)