Final answer:
The Evolutionary Speed Hypothesis is the biodiversity gradient theory characterized by high rates of speciation and species accumulation, shorter generation times, and higher mutation rates.
Step-by-step explanation:
The biodiversity gradient theory characterized by high rates of speciation and species accumulation, shorter generation times, and higher mutation rates is the Evolutionary Speed Hypothesis. This hypothesis suggests that certain factors such as environmental stability, high ambient energy, and short generation times can lead to rapid rates of speciation and species diversification.