Looking forward 500 years requires us to make some assumptions. In the absence of breakthroughs in artificial intelligence, mind uploading, or longevity research (which it would be foolhardy to dismiss on this kind of timescale) none of us are going to be around in any form to observe it. We appear to be living close to the peak of a demographic bubble that will see our population max out or be in decline by 2100. Longevity breakthroughs (as in: a cure for the aging process, and all diseases that currently prevent us from reaching our maximum age) might smear out the descent, but unless old people suddenly start to have more children, it's not going to change it. Longevity breakthroughs would slow down the rate of change of demographic groups, but only in the medium term. 500 years is close to the human mean life expectancy if all medical causes of death are abolished: eventually an accident or violence will get you. So, demographically, the world of 2512 isn't going to resemble our world very closely at all, although it's anyone's guess at this stage as to who will prosper.