Biologic reason for our lifespan

i think that there is a lifespan of like the whole worlds population from what ive seen. (like healthy people from safe countries) is about like 80- 100+. I think that that is the lifespan because without it, there would be sooo many people on the world. lets say you could live 1000 years, thats the average. You could have like 400 babies because women wouldnt loose their stuff until they are like 500 or 600 years. with this and you still have another 500 or 400 years to go with your 400 children,. the world would be way to crowded. my thoughts.

Our lifespan has nothing to do with this "crowded" stuff. If that were the case, we would have been living for 200 years in the past and as we've slowly filled our surroundings our life expectancy has diminished accordingly. It's quite the opposite, as not as far as the Middle Ages, the average life expectancy was around 25-30 years.

As mammals, and ones who have developed/adapted to look after their newborn beyond infancy, we now have things to fill our lives with - hobbies, work, even as simple as watching the paint dry. For many people of old age, it is after a "straw" has been broken (death of a spouse etc.) that the will to live is more diminished and then you just let go.

I'm talking like 97,84% factual stuff here. But yeah this is my opinion and beliefs about the situation.

Basically we age because our bodies get worn out from years of life

We die of old age because our body begins to fail. This is because every time our DNA replicates the telomeres shorten. Eventually our actuall chromosomes are shortened and our cellular functions cannot perform.

Exactly what I came here to post. I'm no expert scientist, but I'm of the opinion that our lifespans can only be extended so far by advances in medicine, and that we're beginning to push that boundary right now. A better way, if it's possible, would be to have children later in life intentionally, so that individuals with longer telomeres can propagate their genes.