As terrible as many diseases are for individuals, are there any diseases in humans which may actually help humankind in the long run?
For example, could the many types of cancer possibly be an ongoing mutation which could develop into a useful adaptation for some future time? Could the wild cell production of cancer for instance, be a precursor to the ability to regenerate human limbs? For the individual, the disease could be catastrophic while for the human species a new tool for survival could be developing.
Well, the same genetic blip that causes sicle cell anemia also gives its posessors a natural immunity to malaria.
Is that sort of what you were thinking?
Well, in fact, diseases are beneficial: they stimulate the immune system to defend the body. There is a theory at present that the upswing in diseases such as asthma and allergies are a result of people living in too-clean, too-aseptic conditions. Also because of vaccinations preventing disease. The body, which “expects” to have to fight off things like measles and other nasties, instead turns on itself or overreacts to otherwise harmless environmental factors.
I have read that people who have a lot of colds, have a lower incidence of cancer.
it also depends on if you mean strictly the person WITH the disease or the remaining population…
i personally believe that disease is also a reflection of overpopulation… so by thinning the herd, so to speak, the rest of the population (and the planet for that matter) is healtier.
On a related note, some theorize that our bodies expect to need to fight off parasites (worms and the like) and when these defenses are not put to use, they can lead to pesky things like allergies.
Cow pox is a beneficial disease in humans, in that it immunizes against a much worse disease.
Regarding the cancer question, my sense would be against what you suggest. Our bodies have evolved elaborate defenses against cancer, and it is when all these fail that a malignancy occurs. If there were some benefit to cancer, why evolve defenses? Also, remember that for a mutation to be evolutionarily significant, it must be heritable. It must be something passed down through one’s decedents. Cancer, unless genetically based, wouldn’t fit that requirement.
Which is not to say that we humans haven’t found uses for cultures of malignant cells. Monoclonal antibody production utilizes cancerous cells, as I recall.
Certain bacteria are infected by viruses and sometimes this can result in the introduction of DNA to the bacteria. Certain bacteria do not cause disease until they are infected by the right virus. So, I suppose if you considered the pathogenicity of the bacteria an enhancement, and the insertion of the DNA by the phage virus a disease, then that might be an example.
IANA MD or geneticist, but in the case of cancer, a group of cells within the body begins to reproduce themselves in some unforseen manner. I suppose it’s conceivable that skin cells could, for example, change to produce an armored shell that might be useful.
But that’s not enough. The mutated DNA has to get intp sperm or egg cells, which are the only ones that count toward carrying forward the change to future generations.
How thay might happen I couldn;t say. It seems to me more likely that beneficial mutations would more likely happen within sperm or egg cells, and never be evident in the adult carrying them. If the mutated cells become part of a viable embryo, the resulting child would then show the results of the mutation and might pass them on to future generations.
I will watch this thread with interest for comments from those better informed than me.
Well, sorta but not quite. Being a carrier of the sickle cell gene (Having sickle trait rather than sickle disease) does not confer immunity to malaria, but rather makes the carrier more resistant to getting it, and to tend to have milder cases of it when one does get it. So it’s somewhat protective to have one copy of the sickle cell gene, but it doesn’t make one invulnerable vis a vis malaria.