As discussed in the first paragraph of the passage, Sanders' analogy between the deep sea and the Amazon basin involves which one of the following assumptions? A. Both the Amazon basin and the deep sea support an unusually high rate of speciation. B. Both the rain-forest trees in the Amazon basin and the mud-dwelling animals in the deep sea have survived for 30 million years. C. Both the deep sea and the Amazon basin have not experienced dramatic changes in climate or physical conditions. D. A dependable supply of water to the Amazon basin and the deep sea has moderated the rate of extinction in both habitats. E. The rate of speciation in the Amazon basin is equivalent to the rate of speciation in the deep sea.