Over periods hundreds of thousands of year’s people have been traveling from Asia to Europe and Africa. They may have moved due to changes in climate whatever the reasons as animals moved north. During these cold periods when the ocean levels were lower scientists believe people traveled from continent to continent by way of Land bridges because of the ice age but when the ice melted the land bridge was completely flooded. Scientists also believe that 40 thousand to 12,000 years the same people crossed from Asia to North America by way of the land bridge.