Two sides to every story:
http://www.beyondveg.com/billings-t...-fruit-1a.shtml
Wild / Natural Fruit
Small, high in fiber, often sour, bitter, or even astringent; rarely sweet; usually low sugar level.
Modern / Cultivated Fruit
Large, low in fiber, usually very sweet with a very high sugar level.
There is probably the truth somewhere in between,
It is my observation that fruit is not available all year, and therefore we humans have never evolved eating fruit regularly.
Fruit ripens right before the starvation season. In temperate zones the starvation season is winter, and in the tropics, it's the dry season.
Ripening fruit before the starvation season allows the fruit eating animals to fatten themselves up. Those with the sweetest sweet tooth tastes got the fattest and were able to survive on those reserves, therefore passing those sweet loving genes to their offspring.
Parts of Africa have a wicked dry season, so the fruit there has to have more sugar. Plus DNA evidence shows that everybody but the native sub-saharan Africans have some Neanderthal genes in our DNA, so we have the European ape that never saw those African fruits in our genes.
Living in the tropics I've seen fruit ripening season for the native and many of the cultivars. So much fruit that you can't possible eat it all. Oranges, mangoes, star fruit, and so on rotting on the ground or packed into UPS boxes for relatives 'up north' because everybody has more than they can possible eat. A month later, there is none to be found, and will not return for another year.
And I've seen a documentary on apples, and the heritage, wild apples in Kazakhstan is now considered a "dwarf apple" comparing it to modern apples. And DNA studies have pointed the origin of apples to these 'dwarf apples' in Kazakhstan.
The corn found by the setters in North America was also much smaller and less sweet than what we eat today. What we eat today is a hybrid and increasingly a Genetically Modified Organism.
We've been 'improving' the size and taste of plants by selective breeding ever since we discovered agriculture.
So I think there is validity in both sides of the debate. And I also know that year-round access to fruit is something humans have not had until very recent times, a speck in our evolutionary clock.
Bob