this top actualy relates to this book i've been reading. Botany of desire. It talks about an idea of co-evolution, where plants need us (animals) to help them, and we need them (plants/fruit/vegitation) to help us. We use eachother to evolve. for existance the tulip and the apple. Each of these produce offspring which are less then 1% simalar to their parent. They produce many offspring per plant, and thousands of combonations of genes. Why? to produce the offspring that will sucsseed and produce even more.
for example, Bee's are drawn to symetry and color. Humans are drawn to uniqueness, and beauty. As tulips produce more and more symetrical flowers more and more bee's take the pollen and travel to more and more plants. Spreading its genes to more and more flowers. They exploit the bees love of symetry for their own personal agenda.
like wize, there is a type of fungas which can attach itself to the tulip. This fungas seperates the two layers of colors in the tulip, producing a swirl of colors. they call this a broken tulip. This tulip is bold and beautiful, and tends to captivate human intrest. This fungi exploits the beuaty it creates (which also destroys the flower) to advance ITS own personal agenda.

I think its possible for co-evolution to be co-deevolution. We can ping pong back and forth with an oposite culture to advance our own, but unknowlingly, we can pick away at each other creating a slow descent of a spiral of de-evolution. We may just pick away at eachother bit by bit until one day, a nuke is launched to control the other (similar to how we would use a pesticide on the tulip to kill the fungus).

think about it.