According to scientists, how did early people migrate out of africa and into new places? a. they used the wheel. c. they used ships. b. they used land bridges. d. they used technology. select the best answer from the choices provided a b c d

The correct answer is B. They used land bridges

Explanation:

Most theories related to human development and expansion towards all continents claim humans first emerge in Africa and then migrate to different parts of the world including Europe, Asia, and America. Moreover, as it is estimated this occurred more than 20,000 years ago when there were no technologies such as automobiles, ships or airplanes, it is believed humans used land bridges, which are natural bridges between continents or different zones, to migrate from Africa to other continents. For example, the Bering land bridge that connected Asia and America was used for human groups to get to America. Thus, early people migrate out of Africa using land bridges.

the earth’s crust is broken into separate pieces called tectonic plates (fig. 7.14). recall that the crust is the solid, rocky, outer shell of the planet. it is composed of two distinctly different types of material: the less-dense continental crust and the more-dense oceanic crust. both types of crust rest atop solid, upper mantle material. the upper mantle, in turn, floats on a denser layer of lower mantle that is much like thick molten tar.

each tectonic plate is free-floating and can move independently. earthquakes and volcanoes are the direct result of the movement of tectonic plates at fault lines. the term fault is used to describe the boundary between tectonic plates. most of the earthquakes and volcanoes around the pacific ocean basin—a pattern known as the “ring of fire”—are due to the movement of tectonic plates in this region. other observable results of short-term plate movement include the gradual widening of the great rift lakes in eastern africa and the rising of the himalayan mountain range. the motion of plates can be described in four general patterns:

collision: when two continental plates are shoved together

subduction: when one plate plunges beneath another (fig. 7.15)

spreading: when two plates are pushed apart (fig. 7.15)

transform faulting: when two plates slide past each other (fig. 7.15)