Mitosis
milhayser | October 1, 2013On Pharyngula, PZ Myers says that cancer, unlike an infectious bacterium or virus, is not the product of millions of years of evolution. Instead, PZ writes, “Cancer misuses and perverts existing processes in your cells to send them out of control.” But what causes cancer? Well, it happens about 20,000 times a day in your body. Luckily, it is almost always repaired. It is the mutation of DNA during cell division. Just one base out of place, and suddenly the gene that made a protein to tightly regulate cell division is making a protein that encourages the cell to divide continually. Depending…
esiegel | March 24, 2008This is some very basic biology: when resources are unlimited and there are no pressures on a species, its population grows exponentially. There's also no evolution other than random mutations; without selection pressures (regardless of whether it's natural or artificial), the genetic information content of a species doesn't change appreciably.
Biologists make use of this to perform tests on certain cells. If you simply put a population of cells in a petrie dish and left them there, they start out by doing this:
They divide. They take over the dish. But then, they run out of room. And when…