Answer:
Trans-Saharan trade requires travel across the Sahara between sub-Saharan Africa and North Africa. While existing from prehistoric times, the peak of trade extended from the 8th century until the early 17th century. The Sahara once had a very different environment
Sociocultural evolution<span>, </span>sociocultural evolutionism<span> or </span>cultural evolution<span> are theories of cultural and </span>social evolution<span> that describe how</span>cultures<span> and </span>societies<span> change over time. Whereas sociocultural development traces processes that tend to increase the </span>complexity<span> of a society or culture, sociocultural evolution also considers process that can lead to decreases in complexity (</span>degeneration) or that can produce variation or proliferation without any seemingly significant changes in complexity .<span> evolution is "the process by which structural reorganization is affected through time, eventually producing a form or structure which is qualitatively different from the ancestral form".</span>
In this context alliance would mean to come to a formal agreement to help each other.
