Final answer:
Trans-Saharan trade increased the economic and cultural connections between West Africa and Europe, leading to prosperity through gold trade but also to adverse effects with the shift towards the Atlantic slave trade.
Step-by-step explanation:
The trans-Saharan trade significantly impacted West Africa in various ways. When the Ghana Empire rose to power and Islamic conquests unified North Africa culturally, the region became a hub for economic expansion, particularly for commodities like gold. This led to European coins being minted with West African gold for the first time, marking a surge in the market's growth. The development and expansion of trade routes, like those between Sijilmasa and Awdaghost, facilitated the flow of not only goods but also cultural influences across the Sahara. However, from the sixteenth century onwards, following the decline of powerful empires like Songhai, the trade shifted towards the Atlantic with European involvement increasing, particularly in the slave trade, which had dire consequences for West African societies.