That's a tough one, but IMO although the gene pool is smaller than it was 150 years ago, it's still plenty big enough. Elephant populations generally are increasing, and the biggest problem is that many countries don't have the courage to defy the stupidity of the political correctness of the western world and manage their herds properly with proper responsible culling and management programmes.

There are still 100 pounders around in plenty of places......but they're expensive to hunt, and by the time they get to that kind of size many are past breeding age anyway. so perhaps there's a valid argument for taking these animals out of the equation and allowing the younger, fitter bulls to breed rather than expend energy in fighting the OAPs

Lions are another problem, and I would say that the Selous Lions (particularly) lack of mane is probably genetic, but I doubt there is any proof whatsoever that this has been affected by hunting. Lack of mane can also be caused by many other factors such as type and thickness of bush and indeed weather and habitiat, there is one area (I think in Zambia) where the Lions spend a lot of their time in or close to swamps & open water. This has caused them to develop much thicker coats and heavier manes than normal. I would guess that a considerable amount of money, expertise and man hours would need to be spent in study before blame could be allocated for shortness of mane.