A period of time when huge sheets of ice covered much of the earth's land, formed from ocean water, leaving ocean levels lower than they are now which exposed dry land that connected the continents.

(a)  

A person who finds food by hunting, fishing, and gathering wild grains, fruits, and nuts.

(a)  

An object made by human beings; often refers to a primitive tool or other relic from an earlier period.

(a)  

The attitudes and behavior that are characteristic of a particular social group or organization.

(a)  

Are humans and their early ancestors.

(a)