Evolution has many pressures. One of them is that long lived, slow-reproducing creatures can't adapt genetically as fast as short-lived ones. So, a species that evolves longer life span and slower reproductive cycle than its environment requires dies out. Douglas Adams gave a hilarious talk on the mating habits of the Kakapo. This bird has a slow reproductive cycle and few young. It evolved to fit an environment in New Zealand with no predators. So it evolved slow reproduction to substitute for predation. These endangered birds also live long lives – 95 years or so.

The hideous naked mole rat is famous (or infamous, depending on your hopes for the oxidation theory of aging) in longevity circles. As rodents go, this one lives for 30 years or so. Not much for a Kakapo, and much less than quite a few birds with much higher metabolisms. But for things mammalian H. glauber is a champ, living 10 times as long as rats of the above-ground variety. Thing is though, that H. glauber has more oxidation than other animals, not less.

Termite queens can live 25-50 years. Queen bees are limited to 3-4 year life spans. I could go on, but that would get boring.

There's a pattern here. Long periods in stable environments allow evolution of longer life span. New Zealand was isolated and it didn't vary so much for a very long time. Going underground is a big adaptation. But once that adaptation is made, the environment is stable for millions of years. I suppose we could become Morlocks and out lives might get very long indeed. Although, now that I think about that, we kind of are Morlocks. Homo cavamen (yes that's real latin, look it up) might be a better name for the human lineage than Homo sapiens. Look at what we spend most of our money on. Really nice caves. They make us comfortable.

Getting back on topic, a species will lengthen its life span to the point that it can continue to evolve. A species can overshoot if a niche appears for a long time that, so to speak, lulls that species into complacency. I think this is the reason that we are designed by evolution to age. We humans are able to adapt to new conditions without changing a lot physically, although we still have evolutionary pressures.

Disease killed 60% of Europe during the black death. Where it originated, in Hubei province of China, it probably killed 90%. This has left scars in our genes. Early records from the Plymouth colony show 90% and more of native population dying from exposure to what appear likely to be influenza, cold viruses and adenoviruses. The civilizations of Central America and South America were brought down by smallpox and other European diseases. In the 1917 influenza, there were native American villages in Canada that had up to 50% of the population die. Disease has been the primary shaper of modern human evolution.

We humans have also adapted to dietary changes that have left many people with the ability to digest lactose, and influenced a variety of genes that improve survival on high meat diets as well as diets high in grains and root vegetables.

Perhaps our minds are what allow us to have longer life-spans. It is interesting that longer life-span in humans may have the strongest association with having purpose, with being useful to society. That evolution would value those who work hard and contribute the most makes sense. Evolution has designed us to get out of the way if we don't.

We will figure this aging business out. It will not be one thing. Regenerating telomerase in all your cells won't do it. There won't be a pill that will stop you from aging. Aging is as complicated as our bodies are. However, we will manage it. Rejuvenation treatments will happen. Embryos will be modified so that those children don't age in the way we know it. There is no reason in physics why we can't live for billions of years – no reason except the laws of chance that dictate that some sort of accident should happen. There may also be physics based limits to memory.

But when we do figure out aging, we will need to deal with what evolution created aging to solve – adaptation. Imagine what it would be like today if everyone who was alive since Galileo's time was still around. While it might be interesting to talk to Galileo, think of how difficult it would be to convince many of the others to accept what we take for granted. From abolition of slavery, to gay marriage and women's right to vote, it would be much more difficult.

Perhaps worse, in science, we could be stopped cold. As Max Planck said, “Scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die.”

If we do not solve that problem of frozen minds, I don't think that Homo longaevitas will last as long as the Kakapo or the Dodo birds.