Every person starts as one fertilized egg, which by adulthood has turned into roughly 37 trillion cells. But those cells have a formidable challenge. These cells must copy 3.2 billion base pairs of DNA perfectly, about once every 24 hours. To speed up the process, cells start replication in multiple spots with people having tens of thousands of them throughout their genomes.
However, this poses its own challenge: How to know where to start and how to time everything. Without precision control, some DNA might get copied twice, causing cellular pandemonium. Bad things can happen if replication doesn’t start correctly. For DNA to be copied, the DNA double helix must open up, and the resulting single strands are vulnerable to breakage or the process can get stuck.
It takes a tightly coordinated dance involving dozens of proteins for the DNA-copying machinery to start replication at the right point in the cell’s life cycle. Keeping tight reins on the kickoff of DNA replication is particularly important to avoid that pandemonium.
Today, researchers are making steps toward a full understanding of the molecular checks and balances that have evolved in order to ensure that each origin initiates DNA copying once and only once, to produce precisely one complete new genome.
Possible Preaching Angle:
3,000 years ago, King David exclaimed, “I praise you because I am fearfully and wonderfully made; your works are wonderful, I know that full well” (Ps. 139:14). Scientific knowledge has increased exponentially since that time and we should be even more in awe of God’s creative genius on display.
