Natural selection
Step-by-step explanation:
Forelimb provides body support during sitting or walking and absorption of impact forces during landing
- Forelimbs carry the weight because of the angle between the stifle and hock in case of horses
- Forelimbs of whales helps in swimming whereas that of bats helps in swimming in the air
- The actual forelimbs of these mammals do not seem to be optimally arranged because natural selection is generally limited to modifying structures that were present in previous generations and in previous species