A lot of the lower life expectancy was sky-high infant mortality, and if you made it to 10 in 1850 (hardly preindustrial, but preindustrial stats are harder to find) you could expect to live to 60 or so. Presumably you'd compare the cancer rates of your study's skeletons with the cancer rates of today's 60 year olds.
Most of the progress, in absolute terms, with reducing maternal mortality and the infant/toddler death rate in the industrialized countries was actually made before antibiotics were developed, in the late 19th / early 20th centuries. In England in 1851 about 26% of children died before the age of 5, falling to 23% in 1891, 19% in 1911, 11% in 1921, 9% in 1931, and 7% in 1941 (and then we're in the antibiotics era).
https://www.pbs.org/fmc/timeline/dmortality.htm
...I also like the link to play the video via Real player in the upper left corner :)
My top three favorite human accomplishments of all time are:
1. printing press 2. vaccines 3. antibiotics
And the order of the last two is debatable.
Why is the theory an accomplishment? Hooke's and van Leeuwenhoek's first observations of micro-organisms in water drops were treated as a meaningless curiosity for about 150 years, and essentially ignored.
Finally it was realised that here was an alternative to prevailing ideas about infectious disease that had great explanatory power. The war of ideas lasted until the early twentieth century, when the last doctors clinging to the "miasma" theory and its ilk finally gave up.
The theory made vaccines and antibiotics conceptually possible.
If that was true, then age composition would be roughly the same as is now, except for larger number of infants.
You could even argue that if you had weaker infants die, you should end up with statistically stronger adults than now and you should see people live to older age than now.
I don't want to say infant mortality rate wasn't high, I just want to say that it has nothing to do with the topic of the discussion.
For example, the introduction and "ramping up" of testosterone and estrogen at puberty has a significant impact on the human condition that simply cannot apply to the prepubescent state, as does their subsequent decline in menopause and old age in general.
Each stage of life comes with its own signals that can be serious health conditions if present in other stages of life, but completely normal and healthy at the appropriate stage. A tween with acne is rarely something to call the doctor about. But a 3 year old with acne certainly is. A colicky baby needs a soother or some other placation. But a colicky adult certainly needs medical intervention.
So the idea that weak babies make weak adults and strong babies make strong adults doesn't work out as cleanly as this comment suggests.
The mammal strategy traded the long game for the quick win.
We have all sorts of (genetic) machinery who's function is to grow fast but then STOP as we can't support gigantic sizes. (Maybe in part because of the quick and dirty foundations but thermodynamics have scaling issues too)
So we need to shut of all those machines before we get too big.
And so here we happily sit in our bodies, our mammal factory and everything is great; just don't push that big red button over there, or pull that lever or that one or that one or ...
eventually if you live long enough some of those buttons will be pushed and the mammal machinery will do what it evolved to do. grow fast and break things.
A final observation on humans in particular, recently bipedal, have not gotten all the bugs worked out on that. Deployed a monkey patch for dimorphic gender singling requires cron job flipping on a subset of growth machinery some years after the main global shutdown but only flip them on for a season or so; still seeing evidence of switch bounce issues, see ticket BCRA1.
From an evolutionary perspective natur might have just stoped after we gave birth but for humans you need to be still very healthy for much longer.
We have a second evolution which we as a species gained due to our more generic and bigger brain and therefore being able to retain and learn more even through generations.
Whenever nature stoped we continued (glasses, cancer treatment etc.)
I personally would not subscribe to your idea that cancer is our basis and we just let loose.
Cancer is just one sickness of a highly complex system.
And after all why would longevity even be a goal for evolution? It's a wishful human idea of lifing forever. I myself I'm looking forward to NOT life forever and still today the thought of not being able to end my life for good is my worst nightmare next to loosing my mind.
The marsupials of Australia called and would like a word with you.
Or they were hunted to death by organised groups of early humans.
Wales are probably only surviving because their environment is so foreign to humans.
Feel like Argentinosaurus might have had something to say about that argument..
Let's cartoonishly oversimplify cancer so that we can see how life expectancy would affect observed statistics. Let's say cancer occurrence is 0% for people up to age 40, and then starting on the 40th birthday, cancer occurrence is 10% per year. Everyone who gets cancer dies immediately.
Then, imagine that life expectancy in 1500 was 25 years old, standard deviation 10 years (yeah lognormal blah blah just go with it). So, most people don't live to 40, but the ones who do sometimes get cancer.
But then, after 1500, life expectancy mean increases by 0.1 years per year. By the year 2000, life expectancy is 75 years old! Much more cancer is going to happen! Many more of the deaths will be from cancer!
Cancer itself didn't change.
So, these researchers see a lower cancer rate in the bones they're looking at, but they need to do some MATH on the ages these bones and of modern humans to know how to compare cancer rates then to cancer rates now.
Sebb suggested that lower life expectancy leads to less cancer. Dsjoerg defined a hypothetical model that would lead to that happening, and then said that proves Sebb was correct.
That's just circular reasoning. And when the hypothetical doesn't match observed reality it's a sign it might be broken.
These diseases are essentially dying of old age. Better treatment for heart disease will mechanically increase cancer deaths and/or Alzheimer.
There isn't a necessarily good or bad here but those Darwinian forces did eliminate a lot of genetic defects from the population before modern medicine.
In the future though we might be able to yet again eliminate defects not by natural selection but by gene editing while still allowing those individuals to carry on a normal life.
One big thing to consider is how would an 18th century person know they had leukemia? Cancers that don’t have a physical manifestation were probably classified as some other mysterious malady.
What I'd really like to know is incidence of cancer in marsupials, birds and fishes, one would predict it to be markedly lower.
Turns out it was curing the <something>, but the next thing the population would statistically die of was: heart attacks.
It could be very well that it is those people who would die as newborn or children without modern medicine and access to clean water have bigger chances of getting cancer with age.
> If a medieval person was able to survive childhood, then he had about a 50% chance of living up to 50–55 years.
This is from wiki. Our life expectancy is much higher. In fact, contemporary medicine is saving a lot of adults.
So, your claim (that life expectancy hasn't changed much) doesn't contradict the parent's claim (that a lot more people are dying of age-related cancers).
It's 82 today.
The effects are not as dramatic as when infant mortality is included but our life expectancy has absolutely increased.
It's a compelling theory, too, because the average age of a cancer is 66 today. But it really addresses the idea of cancer being less prevalent than less likely.
Living into your 80s was uncommon prior to, well, even 1950. Nowadays, many developed countries have significant cohorts of people 80+ and even 90+. Unfortunately, while those people are alive, they are not particularly healthy. We haven't yet learnt how to expand average "healthspan" as much as average "lifespan".