evolution's time bomb
Cancer has been with us since the dawn of life and may be the price life pays for multi-cellularity.
"I heard starlight gives you cancer, but then again, what doesn't these days?" laughed Stewie Griffin, perhaps the most evil toddler on TV in an episode of Family Guy. This diapered villain in training brings up a good point. Cancers might be the oldest and most widespread diseases we know of with causes ranging from genetic to exposure to toxins and radiation. They've been found in dinosaur bones and ancient Egyptian mummies and it affects many animal species with the same ease that it affects humans.
Cancers are also a reminder that evolution isn't always beneficial. A random mutation in a jaw muscle can give a species a much larger skull and make it much more intelligent. Another snip or tweak in the DNA strand can leave a ticking time bomb in our bodies and one day, a certain type of cell won't die after its maximum number of divisions and spread, interfering with our vital functions. And the strangest thing about cancers is that we replicate the genetic damage that causes them when we're exposed to toxins and radiation so even if you're lucky enough to be spared from a carcinogenic gene, you can still develop a cancer. Stranger still is that some cancers can be caused by certain infections and viruses.
Well hold on moment, you might say. If you can develop cancer from pollution and toxins, why blame evolution? Couldn't we have done this to ourselves? The answer is yes and no. Because we smoke, pollute and ingest additives and preservatives that put us at a much higher risk for developing cancers, we undoubtedly raised cancer rates and fatalities. But what about animals going all the way back to the Cretaceous? What about Egyptian pharaohs and nobles? Cats and dogs? It's highly unlikely you can have the same diseases with the same mechanisms affect so many different species for tens of millions of years without something happening on a genetic level. Anthropology and medicine seem to show that despite its artificial triggers, cancers have a very long history in the DNA of innumerable living things.
How would such a debilitating genetic abnormality survive for so long? Well, living things need to live just long enough to pass on their genes. In fact, most insects die after or in the process of mating. A new generation will now carry their genetic information and whether they survive after the transfer or not is immaterial. Cancers let most living things live long enough to mate and pass on their damaged DNA. When they finally activate, they've already been passed on to the next generation.
It's been a common argument of creationists that evolution is way too perfect to be random. If it was truly random, they say, where are the bad mutations? Cancer is a perfect example of an evolutionary process gone awry. It goes hand in hand with the grim statistic that 99% of all the species that ever existed on our planet are now extinct.
