Marilyn Harris wrote:
 >If the human animal had it's origins in Africa, wouldn't fruit basically be
 >an all-year food source?

Even here in New York we have fruits from May through November. 
That's half a year.

I once had a link to a web page listing hundreds of wild African 
fruits. I can no longer find it.

There is this book. I posted about it in the past. You can read it 
online for free:

Lost Crops of Africa: Volume III: Fruits
http://www.nap.edu/catalog.php?record_id=11879

A quote from the introduction: "Most of Africa's edible native fruits 
are wild. One compilation lists over 1000 different species from 85 
botanical families and even that assessment is probably incomplete."

Here's another book:

Fruits of Warm Climates
http://www.hort.purdue.edu/newcrop/morton/

I think you will find that different fruits in warm climates mature 
throughout the year.

Don.