Elephants can't jump even though they have the same number of bones in their feet as other mammals. The bones in an elephant's foot are more closely packed together than other mammals so they do not have the flexibility or spring mechanisms that would enable them to jump. Besides, jumping requires an upward force to be more than the weight force, and since elephants are so large, it would require a huge amount of leg muscle power to do this. Since elephant legs are not evolved to allow elephants to take off like that, it simply won't happen. There is also no need for elephants to jump to improve their chances of survival. Losing the ability to jump and the increase in their body size must have occurred quite far back in its evolutionary line because of its niche requirements and environmental pressures. An elephant jumping...such a feat would be quite an unnecessary waste of energy.