You probably remember that before a cell can divide into two daughter cells its DNA must be replicated into two duplicate copies. But what you didn't learn in high school biology class is what happens when the DNA is damaged. First let's review normal DNA replication.
Normal DNA Replication
DNA consists of pairs of long molecular strands, and a small army of proteins performs a series of fascinating and complex tasks to make a copy of these paired strands. At designated starting points the strands are separated and each strand then serves as a template upon which a new copy of the other, complementary strand is synthesized.
In the end, the result is two pairs of strands where originally there was just one pair. One intriguing aspect of this operation is that the synthesis is performed in opposite directions on each strand. That is, as the strands are unzipped a "Y" is formed. On one of the single strands, the proteins synthesize a new strand continuously as the original DNA strands are unzipped. This way, as more strand becomes exposed it quickly is covered with a newly synthesized strand.
On the other single strand, however, the proteins synthesize the new strand in the opposite direction, away from the unzipping action. This makes sense because paired DNA strands are chemically anti-parallel. But this makes for a complex process.
As the strand is exposed due to unzipping, the proteins start close to the intersection of the "Y" at the location that has most recently been exposed. The proteins then move away from the intersection as they synthesize the new strand.
At some point the proteins halt, move back toward the intersection of the "Y", and begin the process again on the newly exposed section of strand. Hence on one of the strands replication is continuous (the "leading" strand), and on the other strand replication is discontinuous (the "lagging" strand).
Did it Evolve?
Can you see why evolution is not a very good scientific theory? Evolutionists want us to believe that, in addition to the DNA molecule and its information, this incredible DNA replication process just arose all on its own. And of course this is only the beginning (the DNA has to be used somehow, for instance).
How do evolutionists respond to such criticism? They say that with evolution we are not allowed to be incredulous. Why? Because such disbelief is not scientific.
This means that with evolution one need not search for likely explanations. It is the perfect venue for speculation. Of course anything can happen, but the evolution narrative makes fairy tales appear likely by comparison. How many miracles are we supposed to swallow? Well here is one more.
The normal DNA replication process won't work very well when DNA is damaged, by radiation for example. When such damage is detected the normal copying machines are paused and a special "sloppier copier" is ushered in to do the job. This backup copying machine is able to replicate a damaged section of DNA by not reading it so precisely. This means that there are more copying errors, but a copy with more errors is better than no copy at all.
So now we are to believe that in addition to the normal DNA copying machines, this "sloppier copier" also just happened to evolve along with helper machines that tell it when and where to go to work.
It is remarkable that the theory of evolution is taken seriously. What is utterly astonishing, though, is that evolutionists insist that, every bit as much as gravity, it is a fact.