(Set in an Africa on Alternate Earth 111, known conversationally as Great Lakes Earth)
Outlining the boundaries of Tanzania, Uganda, Burundi, Rwanda, Ehtiopia and Eritrea are a range of mountains called the Aden Bahçesi. Its highest peak stands 21,837 feet above sea level, 1500 feet higher than Denali. East of the mountains isn’t major lakes or rich savanna, but a highland plateau, more like Yellowstone.
(If you're curious as to why Turkey, Iran and Israel are marked in black, that simply means that they don't physically exist on Great Lakes Earth but are instead a portion of the Tethys Sea.)
Considering that, in this scenario, there is a plateau situated inside the equatorial zones, will its presence alter the way the tropical climate in central Africa works? Will East Africa still be the cradle for human evolution, or do we have to look elsewhere?