Age A Byproduct of Cancer Defense?

A reader writes "The International Herald Tribune has an article which says, in brief: they have discovered that aging in mice seems to be a byproduct of the chemicals that prevent cancer" If true, that's quite a double edged sword - avoid death, to cause it later.

Comments

Aging and Cancer

[Renraku]

Chemicals that prevent or help prevent cancer usually tamper with cell division. If cellular division is in some way interrupted or affected by anti-cancer agents, then aging more than normal can easily occur. It goes back to one's preference. Long, suffering life or short, fulfilled life?

Wow

[TheGreenLantern]

This sort of puts a whole new spin on this whole "Cure for Cancer" thing. The study seems to suggest that cancer is inevitable, and any attempts by our body to avoid it result in our own death.

Seems to me that if this is the case, it would have some serious repurcussions on how we currently understand how our bodies work. What is it about our physiologies that makes cancer such an irresitible force?

Re:Evolutionary balance?

[zulux]

There's a 25 year lifespan discrepancy, in which evolution has no effect, because the population (at least of women) can't reproduce!

In most primate cultures, old females still help with rearing the young. There is a hypothesis that this is the reason that females live longer than males - an old male is useless as a 'hunter' while an old femail is moderatly usefull as a child raiser.

Re:Evolutionary balance?

[Reality Master 101]

There's a 25 year lifespan discrepancy, in which evolution has no effect, because the population (at least of women) can't reproduce!

That's an oversimplification of evolution. Evolution cares about maximizing survival of the species. Reproduction is only one factor in that. If reproduction were everything, we would never have split into male/female, since that obviously reduces the ease with which we reproduce.

There are many things that people can do after child bearing to help propagation, such as protection, food production, education or labor.

Re:Evolutionary balance?

[Arrgh]

Evolution has nothing to do with the differential survival of species, and everything to do with that of genes (individual organisms and close relatives, by extension).

Here's a nice quote on the subject from something I just Googled up:

Recall "suicidal" lemmings. Early biologists believed that lemmings (a) practice mass suicide and (b) that this trait is an adaptation benefiting the group. They reasoned that if the lemming population exceeds the carrying capacity of the local environment (if they exhaust food supplies) that the group will become extinct. To prevent group extinction, lemmings kill themselves. The gene for mass suicide is an adaptation benefiting the group to the disadvantage of the individual.

This explanation has several problems. First, lemmings don't kill themselves. They migrate to new areas. They are excellent swimmers. By swimming across fjords in groups, an individual lemming is less likely to be swallowed by predators (safety in numbers).

Second, a gene for suicide will not persist. Vehicles (lemmings) with the suicide gene do not reproduce?they kill themselves. In a population of lemmings with suicide genes, consider that a non-suicidal mutation would be very successful. If some lemmings refrain from killing themselves, they would be reproduce more than suicidal individuals and nonsuicidal genes would quickly predominate.

Richard Dawkins has written about this common misconception at length.

Re:This just in!

[greenfly]

When rats get cancer they get it big time. As in, they get a huge mass that sticks out from their body. It's pretty easy to notice, and it grows bigger and bigger. Some vets will surgically remove it, of course there is no guarantee that it won't just grow back (and it costs quite a bit for a pet you probably paid a few bucks for at most).

Re:Evolutionary balance?

[enkidu]

So let's say we have a species that produces three types of individuals: Males, Females and "Helpers". The helpers don't reproduce, but let's say they are super protective of the herd and fight off preditors. They're not just going to die off in one generation, because they are produced randomly from the mating of males and females. Ah, but if we get this mutation that causes them to not be produced. Natural selection takes over -- the herd that has the protectors is going to be more successful than the herd without them, and thus is (on average) going to survive better. They will win the war of resources.

But "helpers" can't be produced "randomly". There has to exist genes or combinations of genes which express themselves as "helpers". This will eventually lead to "Free loaders" or members of the species with no "helper genes" reducing the number of helper genes because they'll always leave more copies of their genes than those who need to expend energy creating "helpers" who don't reproduce.

Clearly the members of a species interact with each other in very complex ways, and these complex ways contribute to the survival of the species as a whole. Wolf packs, for example, have developed successful survival strategies that depend on group behavior.

You're confusing cultural information with genetic information. Just because the members of a species have evolved genes which allow them to interact with each other in very complex ways and pass down a culture of sorts (memes) doesn't imply that the successful reproduction of genes is driven by anything other than genes. The wolf pack passes down memes (hunting techniques) because it is to the benefit of their genes and memes that they do so. do you really think there are no behaviors in nature that are intrinsic to a species that simply foster overall survival rather than simple survival of the individual?

Good point. Maybe not overall survival, but perhaps survival of the behavior itself. That would make groups of common culture (wolf packs if you will) analogous to individuals with reference to memes and genes. That is memes are to culture groups" as genes are to individuals... Hmmm.

Now that I think about it, it is possible for meme's to evolve which mutually benefit the genes which created the conditions for them. But again, the memes are in it for themselves :-). A meme which does not contribute to its (the memes) survival will not perpetuate itself. Maybe this could lead to meme reproduction and evolution which supercedes the need to maintain genes. Perhaps the creation or transference of intelligence to non-genetic vehicle would be such a leap.

Some interesting food for thought. Many thanks for an interesting insight...

Re:This just in!

[krmt]

So what would you do instead? Stick the cancer in people to get really accurate results?

And you do realize that when we study cancer in rats, it's human cancer cells that get put in the rats? Granted, it's not the same thing, but it's a good model to start from. Unless you'd like to volunteer to be a test subject?

Re:Evolutionary balance?

[csbruce]

According to the alt.folklore.urban FAQ, Disney caused people to believe that Lemmings suicide in march to sea. During the filming of the 1958 Disney nature documentary White Wilderness, the film crew induced lemmings into jumping off a cliff and into the sea in order to document their supposedly suicidal behavior.