Cancer a necessity for evolution?

My professor just told me about a class he had taken when he was in college, and his professors theory on cancer. He said that cancer is necesary for evolution. Seeing ass cancer is mutation of genes and cells, and evolution requires a change or mutation in genes and cells, then if one cannot get cancer, one cannot evolve. He theorized that this is hwy the dinosaurs died - they couldn't get cancer and evolve after the climate change of the comet. So he's saying if we eliminate cancer, evolution will stop. This just struck my interest and I was wondering what you guys would have to say about it. I mean logically it makes sense but i don't know if I buy it.

That's a pretty far-out theory. Cancer kills most of the time.
I was under the impression that to evolve, a species had to survive.
Darwins theory and such.

Interesting, none the less.

And, I have got to add :

Originally posted by kyle6677

Seeing ass cancer

Has GOT to be the funniest typo I have ever seen !!

Thanks for the post,
Lex

As an evolutionary tool, cancer would seem like a dead end. Cancers if untreated are by and large fatal Any shift in cell structure that has potential benift to long term evolution most likely die with the host.

In rapidly breeding population like rats this may work as one "carrier" may have multiple generations of offspring. But on the flip side, if the carrier has susceptability to cancer all the offspring might have it as well.

It is true that cancer is a mutation, but usually in specific genes in the somatic cell lines, ie non-sperm and egg. These mutations usually result in either a lose of function for a mechanism for controlling cell replication or a gain of function in a cell cycle mechanism. This results in the uncontrolled growth of that cell, which will eventually lead to the growth of a tumor. These mutations almost never happen in the germ line, ie sperm and egg, because the system there is geared toward extreme levels of replication already. So when a person gets cancer, in whatever cell type, the mutation can't be transfered to the offspring because it isn't in the germ line. Furthermore most cancers present in the later years of life, after the person has already had kids, so selection for the cancerous individuals wouldn't carry into the next generation.
You have to remember that natural selection is a passive process, where mutations and increased variability in the germ line will confer new traits to offspring slowly over time. The traits that gives the organism the best ability to feed and reproduce get passed on in greater numbers, and over eons this gives the species diversity we see today. The dinosaurs died out because in the environment created by the asteroid impact large plants couldn't get enough sunlight and the temperatures were too cold to grow sufficiently. The large herbivores dependent on them started dieing off because they couldn't get enough food, and the same with the large predators. Smaller animals were better able to find sufficient food amounts, and so they lived on in greater numbers and keep passing on their genes.

Originally posted by kyle6677
He said that cancer is necesary for evolution.

Definately not.

Seeing as cancer is mutation of genes and cells

No, cancer is uncontrolled dividing cells, DUE to mutation. It is not the mutation itself.

He theorized that this is hwy the dinosaurs died - they couldn't get cancer and evolve after the climate change of the comet.

Dinosaurs, like every single cell on the planet, could get cancer. Evolution has squad to do with cancer on a large scale, because the disadvantage/advantage one with cancer would have, would disappear with the persons death. If there are som 'unstable' genes that are prone to mutation, then it does have a negative impact on evolution. But not enough to wipe out an entire planets worth of dinosaurs.. They would never have evolved for such a long time.
So he's saying if we eliminate cancer, evolution will stop. This just struck my interest and I was wondering what you guys would have to say about it. I mean logically it makes sense but i don't know if I buy it.
You definately should'nt buy it. Evolution will go on, cancer or no cancer.

In fact, it sounds as if your professor doesn't really know what cancer is.