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Was cancer less likely in a pre-industrial world?

nationalgeographic.com

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Re: Was cancer less likely in a pre-industrial world?

#81

Post by dheera »

Sebb767 wrote: post #12

One thing which I always thought of, but which the article doesn't mention, is age. Especially older people seem more prone to cancer, so in my mind a lower life expectancy will naturally lead to a lower cancer rate, as people die before cancer "is able to get them". Or am I missing something?

Not only that, but I imagine in pre-industrial times, those who got currently-curable forms of cancer didn't get cured during those times, and Darwinian forces stopped them from reproducing.

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.

Re: Was cancer less likely in a pre-industrial world?

#83

Post by R0b0t1 »

CoryAlexMartin wrote: post #77
mikewarot wrote: post #75

When I saw a great^n grandmother's 1870 census entry, which said she had 7 children, 1 of which was still alive (at 55), the reality of life back then hit me hard. This a meaningless question for most people, if it helps save lives in the future, great. I think you should also pay attention to Bret Weinstein's work on telomeres and cancer. If the environmental pressures are for a low age, you end up with long telomer…

Are our telomeres long enough to allow for the development of cancer, or is it necessary for the system to be overridden, thus allowing cells to replicate indefinitely? My layman's understanding was that benign moles were benign, and not cancerous, because the telomere system was functioning normally and limiting growth. Am I wrong?

Moles don't stop growing primarily because of telomere length but because the human genome has effective methods of controlling cancer. You get cancer something like 4 times a day but the cells are terminated. (It is possible telomeres play some part in this, but I have never seen it proposed.)

What you are likely trying to broach is the question "do organisms evolve to die?" the answer to which is "yes." This was originally studied in pea plants. The maturation of the seed pods sends a chemical signal back to the main plant which induces death. It dies so that its progeny have more space; this is incentivized over generations because a changing genome is more advantageous to a static one.

Same logic can be applied to animals. It is not just that there may be no pressure to evolve telomere repair, it may be that telomere repair is markedly disadvantageous.

Re: Was cancer less likely in a pre-industrial world?

#84

Post by _0w8t »

gruez wrote: post #70
_0w8t wrote: post #51

Earlier quoted context omitted.

During the last 120 years wheat was optimized for machines making its gluten content higher that could explain higher gluten intolerance among people presently.

Is there any evidence supporting this hypothesis?

https://pubmed.ncbi.nlm.nih.gov/20664999/

Re: Was cancer less likely in a pre-industrial world?

#85

Post by triceratops »

sokoloff wrote: post #39
magneticnorth wrote: post #36

Earlier quoted context omitted.

Tobacco was unknown in Europe until Europeans were introduced to it by native Americans. https://en.m.wikipedia.org/wiki/History_of_tobacco

Wow. That’s mind-blowing. I knew it was a huge economic driver in the early American colonies, but I always imagined it pre-dated [in Europe] the colonization. Thank you for my TIL!

The entire Colombian Exchange is eye-opening. Try to imagine Italian food without tomatoes, Indian food without chili peppers, or a Britain with no chips to accompany their fried fish.

Re: Was cancer less likely in a pre-industrial world?

#86

Post by yuliyp »

adolph wrote: post #55
7952 wrote: post #28

Earlier quoted context omitted.

I think evolution plays a part in why older people are more prone. A debilitating illness in your teens is likely to stop you reproducing and is more likely to vanish. But a genetic trait for cancer later in life can get past on.

There must be some evolutionary fitting function that mutations serve that have prevented them from being selected out.

The rate of mutation is significantly lower in humans than in say viruses. Being able to adapt eventually to changing circumstances is valuable.

Re: Was cancer less likely in a pre-industrial world?

#87

Post by tejtm »

Sebb767 wrote: post #12

One thing which I always thought of, but which the article doesn't mention, is age. Especially older people seem more prone to cancer, so in my mind a lower life expectancy will naturally lead to a lower cancer rate, as people die before cancer "is able to get them". Or am I missing something?

Not a biologist, but been around them long enough. I been cultivating a theory that mammals strategy is more or less "go fast; break things". That is, asteroid or not, we were on track to out evolve everything that came before by extending and exploiting explosive cell growth. No animal converts matter & energy to body-mass faster than young mammals, the cold blooded do not stand a chance. The competition would get larger eventually only if some adolescent mammal did not eat them first as peers. consider how you would bet on a 1 year old raccoon vs a 1 year old alligator then again with a 5 year old raccoon vs a 5 year old alligator

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.

Re: Was cancer less likely in a pre-industrial world?

#89

Post by nradov »

Sebb767 wrote: post #12

One thing which I always thought of, but which the article doesn't mention, is age. Especially older people seem more prone to cancer, so in my mind a lower life expectancy will naturally lead to a lower cancer rate, as people die before cancer "is able to get them". Or am I missing something?

Yes if you live long enough eventually some kind of cancer will kill you. This is inevitable due to accumulating cellular damage. Someday it might be possible to repair that damage but it's not clear how.

Re: Was cancer less likely in a pre-industrial world?

#90

Post by deep-root »

szundi wrote: post #82

People didn’t live long enough to have cancer back then.

It's a bit of a myth that humans have only had long life in modern times. This is partially due to the calculated "life expectancy" of many eras including infant mortality where perhaps 30% of the population died at age 0.

If a quarter or half of your population is dying at age 0, then another quarter or half must likely be living into their 70s for the mean age to end up 35.

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