Scientists Ponder the Prospect of Contagious Cancer (cnbc.com)

Cancer causes many deaths each year, and anyone that's lost someone to cancer knows how painful and grueling it can be. The one saving grace is that it ultimately only kills the host. But is this changing? According to several recent papers, scientists have suggested that cancer could become contagious. Cancer cells could have the ability to metastasize, not just from organ to organ, but from person to person. While this is not an imminent threat, it has already happened in unusual circumstances.

Comments

Genetic diversity and human lifespan

[Mostly a lurker]

One puzzle is why evolution has resulted in humans (and the vast majority of other organisms) having a limited lifespan with frequent breeding. Superficially, it would seem more efficient to invest less in the ability to procreate, but permit unlimited healthy lifespans. I have an hypothesis which I think fits with the content of TFA. Frequent breeding allows natural selection to counteract emerging diseases. Where a disease evolves that threatens to wipe out a species, genetic diversity provides an excellent chance that some individuals will be resistant. These resistant individuals can breed to aid species regeneration after being decimated by such a disease.

Re:Genetic diversity and human lifespan

[mysidia]

A simple increase in lifespan won't cause more reproduction, unless it also makes people fertile for a longer number of years, and likely to reproduce more times.

Then there is the issue that evolution is like a simple hill climbing algorithm.

So evolution can get trapped at a local maxima and does not necessarily see that an increase in lifespan makes you more fit in the long run.

Re:See Tazmanian Devil cancer outbreak

[Anonymous Coward]

HPV is transmissible between humans and tends to cause tissue changes that may lead to cancer. Perhaps these viruses should be seen as a life cycle stage of the cancer.. scary thoughts, scary thoughts.