What is one vestigial structure that a modern Baleen whale retains from its past ancestors? a-Hip bones
b-A larger body size
c-Well formed teeth
d-Appendix

  like australopithecus afarensis; probably the direct ancestor of this group. africa: 5.8 to 4.4 million years ago. 

The rate that would change would be the  searching efficiency/attack rate. there are only two other rates in this model: the  growth rate of prey, and the  predator or consumer mortality rate.the  searching efficiency/attack rate is what indicates how effectively can a predator capture its prey whether in the searching process or actual capturing/attacking process.