Ecology 6th Edition by Charles Krebs

Exercise 6

The evolutionary speed hypothesis has been tested with genetic marker data in only one group, birds (Bromham and CardillO₂003). They found no evidence in favor of a higher rate of speciation in tropical areas for birds. Discuss how this finding would change the interpretation of the evolutionary speed hypothesis (e.g., Figure 19.11) if similar results -au are found in many other taxonomic groups. Are these data sufficient to reject the evolutionary speed i hypothesis?
Reference Figure: 19.11