How and why did islam change as it spread along african and indian ocean trade routes?

In Indian Ocean

After the advent of Islam in the Arabian Peninsula in the 7th century, Islam started its expansion towards eastern regions through trade encouraged by the development of the maritime Silk Roads. Muslims were known to have a commercial talent notably encouraged by Islam and excellent sailing skills.

In Africa...

ECONOMIC EFFECTS

Islam promoted trade between West Africa and the Mediterranean. The religion developed and widened the trans-Saharan Caravan trade. The trade enriched the West African and the Muslim traders. Muslims from North Africa came in their numbers and settled in the commercial centres.

Explanation:

they believed democracy was worth the fight